@article {pmid39120521, year = {2024}, author = {Fu, Y and Takeuchi, N}, title = {Evolution of the division of labour between templates and catalysts in spatial replicator models.}, journal = {Journal of evolutionary biology}, volume = {37}, number = {10}, pages = {1158-1169}, doi = {10.1093/jeb/voae098}, pmid = {39120521}, issn = {1420-9101}, support = {//University of Auckland/ ; //Digital Life Institute Seed Funding/ ; }, mesh = {*Biological Evolution ; Models, Biological ; Catalysis ; Models, Genetic ; }, abstract = {The central dogma of molecular biology can be conceptualised as the division of labour between templates and catalysts, where templates transmit genetic information, catalysts accelerate chemical reactions, and the information flows from templates to catalysts but not from catalysts to templates. How can template-catalyst division evolve in primordial replicating systems? A previous study has shown that even if the template-catalyst division does not provide an immediate fitness benefit, it can evolve through symmetry breaking between replicating molecules when the molecules are compartmentalised into protocells. However, cellular compartmentalisation may have been absent in primordial replicating systems. Here, we investigate whether cellular compartmentalisation is necessary for the evolution of the template-catalyst division via symmetry breaking using an individual-based model of replicators in a two-dimensional space. Our results show that replicators evolve the template-catalyst division via symmetry breaking when their diffusion constant is sufficiently high, a condition that results in low genetic relatedness between replicators. The evolution of the template-catalyst division reduces the risk of invasion by "cheaters," replicators that have no catalytic activities, encode no catalysts, but replicate to the detriment of local population growth. Our results suggest that the evolution of the template-catalyst division via symmetry breaking does not require cellular compartmentalization and is, instead, a general phenomenon in replicators with structured populations.}, }
@article {pmid39314835, year = {2024}, author = {Dong, B and Paracchini, S and Gardner, A}, title = {Kin selection as a modulator of human handedness: sex-specific, parental and parent-of-origin effects.}, journal = {Evolutionary human sciences}, volume = {6}, number = {}, pages = {e32}, pmid = {39314835}, issn = {2513-843X}, abstract = {The frequency of left-handedness in humans is ~10% worldwide and slightly higher in males than females. Twin and family studies estimate the heritability of human handedness at around 25%. The low but substantial frequency of left-handedness has been suggested to imply negative frequency-dependent selection, e.g. owing to a 'surprise' advantage of left-handers in combat against opponents more used to fighting right-handers. Because such game-theoretic hypotheses involve social interaction, here we perform an analysis of the evolution of handedness based on kin-selection, which is understood to play a major role in the evolution of social behaviour generally. We show that: (1) relatedness modulates the balance of right-handedness vs. left-handedness, according to whether left-handedness is marginally selfish vs. marginally altruistic; (2) sex differences in relatedness to social partners may drive sex differences in handedness; (3) differential relatedness of parents and offspring may generate parent-offspring conflict and sexual conflict leading to the evolution of maternal and paternal genetic effects in relation to handedness; and (4) differential relatedness of maternal-origin vs. paternal-origin genes may generate intragenomic conflict leading to the evolution of parent-of-origin-specific gene effects - such as 'genomic imprinting' - and associated maladaptation.}, }
@article {pmid39255001, year = {2024}, author = {Dos Santos, M and Downing, PA and Griffin, AS and Cornwallis, CK and West, SA}, title = {Altruism and natural selection in a variable environment.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {121}, number = {38}, pages = {e2402974121}, pmid = {39255001}, issn = {1091-6490}, support = {834164//EC | ERC | HORIZON EUROPE European Research Council (ERC)/ ; SESE//EC | ERC | HORIZON EUROPE European Research Council (ERC)/ ; WAF 2018.0138//Knut och Alice Wallenbergs Stiftelse (Knut and Alice Wallenberg Foundation)/ ; VR 2017-03880//Vetenskapsrådet (VR)/ ; }, mesh = {*Altruism ; Animals ; *Selection, Genetic ; *Birds/physiology ; Reproduction/physiology ; Biological Evolution ; Environment ; Behavior, Animal/physiology ; Social Behavior ; Cooperative Behavior ; Helping Behavior ; }, abstract = {Hamilton's rule provides the cornerstone for our understanding of the evolution of all forms of social behavior, from altruism to spite, across all organisms, from viruses to humans. In contrast to the standard prediction from Hamilton's rule, recent studies have suggested that altruistic helping can be favored even if it does not benefit relatives, as long as it decreases the environmentally induced variance of their reproductive success ("altruistic bet-hedging"). However, previous predictions both rely on an approximation and focus on variance-reducing helping behaviors. We derived a version of Hamilton's rule that fully captures environmental variability. This shows that decreasing (or increasing) the variance in the absolute reproductive success of relatives does not have a consistent effect-it can either favor or disfavor the evolution of helping. We then empirically quantified the effect of helping on the variance in reproductive success across 15 species of cooperatively breeding birds. We found that a) helping did not consistently decrease the variance of reproductive success and often increased it, and b) the mean benefits of helping across environments consistently outweighed other variability components of reproductive success. Altogether, our theoretical and empirical results suggest that the effects of helping on the variability components of reproductive success have not played a consistent or strong role in favoring helping.}, }
@article {pmid39247287, year = {2024}, author = {He, J and Zhao, Y and Chen, B and Bao, Y and Xiao, Z}, title = {Similarity enhances psychological compatibility: Serial mediation effect of psychological kinship and intergroup contact.}, journal = {Heliyon}, volume = {10}, number = {16}, pages = {e36262}, pmid = {39247287}, issn = {2405-8440}, abstract = {PURPOSE: This study elucidates the relationship between similarity and ethnic psychological compatibility and its underlying psychological mechanisms. According to kin selection theory, similarity can promote ethnic psychological compatibility by enhancing psychological kinship and intergroup contact.<br><br>PARTICIPANTS: and methods: A questionnaire survey was administered to 1523 participants from 25 ethnic groups in China. Data analysis was carried out via conditional process modelling. A multigroup comparison of mediation models between the ethnic majority and minorities was detected via the Stats Tools Package.<br><br>RESULTS: Our findings demonstrated that: (1) cultural and attitude similarity both showed a significant positive correlation with ethnic psychological compatibility; (2) psychological kinship and intergroup contact served as mediators in the relationship of attitude and cultural similarity with ethnic psychological compatibility and psychological kinship and intergroup contact were independent mediators, while psychological kinship-intergroup contact showed a significant serial mediation effect; (3) there were no significant differences in mediation effects between different ethnic groups.<br><br>CONCLUSION: Our findings expand on kin selection theory and provide valuable paths for psychologically supporting ethnic psychological compatibility.}, }
@article {pmid39182628, year = {2024}, author = {Andersen, K and Rothausen, KW and Håberg, SE and Myrskylä, M and Ramlau-Hansen, CH and Gaml-Sørensen, A}, title = {Sibling relatedness and pubertal development in girls and boys: A population-based cohort study.}, journal = {Annals of epidemiology}, volume = {98}, number = {}, pages = {51-58}, doi = {10.1016/j.annepidem.2024.08.004}, pmid = {39182628}, issn = {1873-2585}, mesh = {Humans ; Male ; Female ; Denmark ; *Siblings/psychology ; *Puberty/psychology/physiology ; Child ; Adolescent ; Cohort Studies ; Sibling Relations ; }, abstract = {PURPOSE: To investigate the association between sibling relatedness and pubertal development in girls and boys.<br><br>METHODS: This cohort study consisted of 10,657 children from the Puberty Cohort, Denmark. Information on sibling relatedness was obtained by self-report. Information on pubertal markers was obtained half yearly from age 11 and throughout puberty. Mean age difference at attaining pubertal markers was estimated using interval-censored regression models according to sibling relatedness (full, half and/or step siblings; half and/or step siblings; no siblings; relative to full siblings).<br><br>RESULTS: Girls with both full, half and/or step siblings (-1.2 (CI 95&#xa0;%: -2.5; 0.1) months), only half- and/or stepsiblings (-2.2 (CI 95&#xa0;%: -3.7; -0.7) months), and no siblings (-5.5 (CI 95&#xa0;%: -8.5; -2.5) months) entered puberty earlier than girls with full siblings. Boys with full, half and/or step siblings (-1.4 (CI 95&#xa0;%: -2.7; -0.1) months), only half and/or step siblings (-1.2 (CI 95&#xa0;%: -3.0; 0.6) months), and no siblings (-4.5 (CI 95&#xa0;%: -8.8; -0.3) months) entered puberty earlier than boys with full siblings.<br><br>CONCLUSIONS: Children with sibling relatedness other than full siblings entered puberty earlier than their peers with full siblings even after adjustment for parental cohabitation status, childhood body mass index and childhood internalizing and externalizing symptoms.}, }
@article {pmid39152078, year = {2024}, author = {Cremer, S and Pull, CD}, title = {Unconditional versus condition-dependent social immunity.}, journal = {Trends in parasitology}, volume = {40}, number = {9}, pages = {780-787}, doi = {10.1016/j.pt.2024.07.014}, pmid = {39152078}, issn = {1471-5007}, mesh = {Animals ; *Social Behavior ; Insecta/immunology/physiology ; Reproduction/immunology/physiology ; Behavior, Animal/physiology ; }, abstract = {Socially living animals can counteract disease through cooperative defences, leading to social immunity that collectively exceeds the sum of individual defences. In superorganismal colonies of social insects with permanent caste separation between reproductive queen(s) and nonreproducing workers, workers are obligate altruists and thus engage in unconditional social immunity, including highly specialised and self-sacrificial hygiene behaviours. Contrastingly, cooperation is facultative in cooperatively breeding families, where all members are reproductively totipotent but offspring transiently forgo reproduction to help their parents rear more siblings. Here, helpers should either express condition-dependent social immunity or disperse to pursue independent reproduction. We advocate inclusive fitness theory as a framework to predict when and how indirect fitness gains may outweigh direct fitness costs, thus favouring conditional social immunity.}, }
@article {pmid39110731, year = {2024}, author = {Rees-Baylis, E and Pen, I and Kreider, JJ}, title = {Maternal manipulation of offspring size can trigger the evolution of eusociality in promiscuous species.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {121}, number = {33}, pages = {e2402179121}, pmid = {39110731}, issn = {1091-6490}, mesh = {Animals ; Female ; *Social Behavior ; *Biological Evolution ; *Body Size ; *Sexual Behavior, Animal/physiology ; *Reproduction/physiology ; Male ; Models, Biological ; Behavior, Animal/physiology ; }, abstract = {Eusocial organisms typically live in colonies with one reproductive queen supported by thousands of sterile workers. It is widely believed that monogamous mating is a precondition for the evolution of eusociality. Here, we present a theoretical model that simulates a realistic scenario for the evolution of eusociality. In the model, mothers can evolve control over resource allocation to offspring, affecting offspring's body size. The offspring can evolve body-size-dependent dispersal, by which they disperse to breed or stay at the nest as helpers. We demonstrate that eusociality can evolve even if mothers are not strictly monogamous, provided that they can constrain their offspring's reproduction through manipulation. We also observe the evolution of social polymorphism with small individuals that help and larger individuals that disperse to breed. Our model unifies the traditional kin selection and maternal manipulation explanations for the evolution of eusociality and demonstrates that-contrary to current consensus belief-eusociality can evolve despite highly promiscuous mating.}, }
@article {pmid38903092, year = {2024}, author = {Updegrove, TB and Delerue, T and Anantharaman, V and Cho, H and Chan, C and Nipper, T and Choo-Wosoba, H and Jenkins, LM and Zhang, L and Su, Y and Shroff, H and Chen, J and Bewley, CA and Aravind, L and Ramamurthi, KS}, title = {Altruistic feeding and cell-cell signaling during bacterial differentiation actively enhance phenotypic heterogeneity.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, pmid = {38903092}, issn = {2692-8205}, abstract = {Starvation triggers bacterial spore formation, a committed differentiation program that transforms a vegetative cell into a dormant spore. Cells in a population enter sporulation non-uniformly to secure against the possibility that favorable growth conditions, which puts sporulation-committed cells at a disadvantage, may resume. This heterogeneous behavior is initiated by a passive mechanism: stochastic activation of a master transcriptional regulator. Here, we identify a cell-cell communication pathway that actively promotes phenotypic heterogeneity, wherein Bacillus subtilis cells that start sporulating early utilize a calcineurin-like phosphoesterase to release glycerol, which simultaneously acts as a signaling molecule and a nutrient to delay non-sporulating cells from entering sporulation. This produced a more diverse population that was better poised to exploit a sudden influx of nutrients compared to those generating heterogeneity via stochastic gene expression alone. Although conflict systems are prevalent among microbes, genetically encoded cooperative behavior in unicellular organisms can evidently also boost inclusive fitness.}, }
@article {pmid38842146, year = {2024}, author = {Munasinghe, M and Brandvain, Y}, title = {Together Inbreeding and Reproductive Compensation Favor Lethal t-Haplotypes.}, journal = {The Journal of heredity}, volume = {}, number = {}, pages = {}, doi = {10.1093/jhered/esae030}, pmid = {38842146}, issn = {1465-7333}, abstract = {Male mice who are heterozygous for distorting and non-distorting alleles at the t-haplotype transmit the driving t-haplotype around 90% of the time - a drastic departure from Mendelian expectations. This selfish act comes at a cost. The mechanism underlying transmission distortion in this system causes severe sterility in males homozygous for the drive alleles, ultimately preventing its fixation. Curiously, many driving t-haplotypes also induce embryonic lethality in both sexes when homozygous; however, this is neither universal nor a necessity for this distortion mechanism. Charlesworth provided an adaptive explanation for the evolution of lethal t-haplotypes in a population segregating for distorting and non-distorting t alleles - if mothers compensate by replacing dead embryos with new offspring (or by transferring energy to surviving offspring), a recessive lethal can be favored because it effectively allows mothers the opportunity to trade in infertile males for potentially fertile offspring. This model, however, requires near complete reproductive compensation for the invasion of the lethal t-haplotype and produces an equilibrium frequency of lethal drivers well below what is observed in nature. We show that low levels of systemic inbreeding, which we model as brother-sister mating, allow lethal t-haplotypes to invade with much lower levels of reproductive compensation. Furthermore, inbreeding allows these lethal haplotypes to largely displace the ancestral male-sterile haplotypes. Our results show that together inbreeding and reproductive compensation move expected equilibria closer to observed haplotype frequencies in natural populations and occur under lower, potentially more reasonable, parameters.}, }
@article {pmid38818418, year = {2024}, author = {Ferreira, HM and Alves, DA and Cool, L and Oi, CA and Oliveira, RC and Wenseleers, T}, title = {Toward greater realism in inclusive fitness models: the case of caste fate conflict in insect societies.}, journal = {Evolution letters}, volume = {8}, number = {3}, pages = {387-396}, pmid = {38818418}, issn = {2056-3744}, abstract = {In the field of social evolution, inclusive fitness theory has been successful in making a wide range of qualitative predictions on expected patterns of cooperation and conflict. Nevertheless, outside of sex ratio theory, inclusive fitness models that make accurate quantitative predictions remain relatively rare. Past models dealing with caste fate conflict in insect societies, for example, successfully predicted that if female larvae can control their own caste fate, an excess should opt to selfishly develop as queens. Available models, however, were unable to accurately predict levels of queen production observed in Melipona bees-a genus of stingless bees where caste is self-determined-as empirically observed levels of queen production are approximately two times lower than the theoretically predicted ones. Here, we show that this discrepancy can be resolved by explicitly deriving the colony-level cost of queen overproduction from a dynamic model of colony growth, requiring the incorporation of parameters of colony growth and demography, such as the per-capita rate at which new brood cells are built and provisioned, the percentage of the queen's eggs that are female, costs linked with worker reproduction and worker mortality. Our revised model predicts queen overproduction to more severely impact colony productivity, resulting in an evolutionarily stable strategy that is approximately half that of the original model, and is shown to accurately predict actual levels of queen overproduction observed in different Melipona species. Altogether, this shows how inclusive fitness models can provide accurate quantitative predictions, provided that costs and benefits are modeled in sufficient detail and are measured precisely.}, }
@article {pmid38785769, year = {2024}, author = {Kuszewska, K and Woloszczuk, A and Woyciechowski, M}, title = {Reproductive Cessation and Post-Reproductive Lifespan in Honeybee Workers.}, journal = {Biology}, volume = {13}, number = {5}, pages = {}, pmid = {38785769}, issn = {2079-7737}, support = {2019/35/B/NZ8/00666//National Science Center/ ; DS/BiNoZ/INo&#x15a;/761/10-14//Jagiellonian University/ ; }, abstract = {The post-reproductive lifespan is an evolutionary enigma because the cessation of reproduction in animals seems contrary to the maximization of Darwinian fitness. Several theories aim to explain the evolution of menopause, one of which suggests that females of a certain age receive more fitness benefits via indirect selection (kin selection) than they would directly from continuing reproduction. Post-reproductive lifespans are not very common in nature but have been described in humans, nonhuman primates, a few species of toothed whales, guppies, and in some insect societies consisting of clonal colony members, such as aphid and ant societies. Here, we provide evidence that menopause also exists in honeybee societies. Our study shows that workers with a short life expectancy (older and/or injured workers) invest fewer resources and less time in their own reproduction than workers with a long life expectancy (younger and/or uninjured workers), even if their colony is hopelessly queenless. These results are consistent with the kin selection explanation for the evolution of menopause and help us understand the net effects of relatedness and social cooperation in animals.}, }
@article {pmid38772422, year = {2024}, author = {Walsman, JC and Lambe, M and Stephenson, JF}, title = {Associating with kin selects for disease resistance and against tolerance.}, journal = {Proceedings. Biological sciences}, volume = {291}, number = {2023}, pages = {20240356}, pmid = {38772422}, issn = {1471-2954}, mesh = {Animals ; *Poecilia/physiology/parasitology ; *Disease Resistance ; *Host-Parasite Interactions ; Fish Diseases/parasitology ; Biological Evolution ; Models, Biological ; }, abstract = {Behavioural and physiological resistance are key to slowing epidemic spread. We explore the evolutionary and epidemic consequences of their different costs for the evolution of tolerance that trades off with resistance. Behavioural resistance affects social cohesion, with associated group-level costs, while the cost of physiological resistance accrues only to the individual. Further, resistance, and the associated reduction in transmission, benefit susceptible hosts directly, whereas infected hosts only benefit indirectly, by reducing transmission to kin. We therefore model the coevolution of transmission-reducing resistance expressed in susceptible hosts with resistance expressed in infected hosts, as a function of kin association, and analyse the effect on population-level outcomes. Using parameter values for guppies, Poecilia reticulata, and their gyrodactylid parasites, we find that: (1) either susceptible or infected hosts should invest heavily in resistance, but not both; (2) kin association drives investment in physiological resistance more strongly than in behavioural resistance; and (3) even weak levels of kin association can favour altruistic infected hosts that invest heavily in resistance (versus selfish tolerance), eliminating parasites. Overall, our finding that weak kin association affects the coevolution of infected and susceptible investment in both behavioural and physiological resistance suggests that kin selection may affect disease dynamics across systems.}, }
@article {pmid38713735, year = {2024}, author = {Oszoli, I and Zachar, I}, title = {Group-selection via aggregative propagule-formation enables cooperative multicellularity in an individual based, spatial model.}, journal = {PLoS computational biology}, volume = {20}, number = {5}, pages = {e1012107}, pmid = {38713735}, issn = {1553-7358}, mesh = {*Models, Biological ; *Biological Evolution ; Computational Biology ; Ecosystem ; Animals ; Predatory Behavior/physiology ; Selection, Genetic ; Computer Simulation ; }, abstract = {The emergence of multicellularity is one of the major transitions in evolution that happened multiple times independently. During aggregative multicellularity, genetically potentially unrelated lineages cooperate to form transient multicellular groups. Unlike clonal multicellularity, aggregative multicellular organisms do not rely on kin selection instead other mechanisms maintain cooperation against cheater phenotypes that benefit from cooperators but do not contribute to groups. Spatiality with limited diffusion can facilitate group selection, as interactions among individuals are restricted to local neighbourhoods only. Selection for larger size (e.g. avoiding predation) may facilitate the emergence of aggregation, though it is unknown, whether and how much role such selection played during the evolution of aggregative multicellularity. We have investigated the effect of spatiality and the necessity of predation on the stability of aggregative multicellularity via individual-based modelling on the ecological timescale. We have examined whether aggregation facilitates the survival of cooperators in a temporally heterogeneous environment against cheaters, where only a subset of the population is allowed to periodically colonize a new, resource-rich habitat. Cooperators constitutively produce adhesive molecules to promote aggregation and propagule-formation while cheaters spare this expense to grow faster but cannot aggregate on their own, hence depending on cooperators for long-term survival. We have compared different population-level reproduction modes with and without individual selection (predation) to evaluate the different hypotheses. In a temporally homogeneous environment without propagule-based colonization, cheaters always win. Predation can benefit cooperators, but it is not enough to maintain the necessary cooperator amount in successive dispersals, either randomly or by fragmentation. Aggregation-based propagation however can ensure the adequate ratio of cooperators-to-cheaters in the propagule and is sufficient to do so even without predation. Spatiality combined with temporal heterogeneity helps cooperators via group selection, thus facilitating aggregative multicellularity. External stress selecting for larger size (e.g. predation) may facilitate aggregation, however, according to our results, it is neither necessary nor sufficient for aggregative multicellularity to be maintained when there is effective group-selection.}, }
@article {pmid38659681, year = {2024}, author = {Andersen, S}, title = {The maps of meaning consciousness theory.}, journal = {Frontiers in psychology}, volume = {15}, number = {}, pages = {1161132}, pmid = {38659681}, issn = {1664-1078}, abstract = {In simple terms, consciousness is constituted by multiple goals for action and the continuous adjudication of such goals to implement action, which is referred to as the maps of meaning (MoM) consciousness theory. The MoM theory triangulates through three parallel corollaries: action (behavior), mechanism (morphology/pathophysiology), and goals (teleology). (1) An organism's consciousness contains fluid, nested goals. These goals are not intentionality, but intersectionality, via the Darwinian byproduct of embodiment meeting the world, i.e., Darwinian inclusive fitness or randomization and then survival of the fittest. (2) These goals are formed via a gradual descent under inclusive fitness and are the abstraction of a "match" between the evolutionary environment and the organism. (3) Human consciousness implements the brain efficiency hypothesis, genetics, epigenetics, and experience-crystallized efficiencies, not necessitating best or objective but fitness, i.e., perceived efficiency based on one's adaptive environment. These efficiencies are objectively arbitrary but determine the operation and level of one's consciousness, termed as extreme thrownness. (4) Since inclusive fitness drives efficiencies in the physiologic mechanism, morphology, and behavior (action) and originates one's goals, embodiment is necessarily entangled to human consciousness as it is at the intersection of mechanism or action (both necessitating embodiment) occurring in the world that determines fitness. (5) Perception is the operant process of consciousness and is the de facto goal adjudication process of consciousness. Goal operationalization is fundamentally efficiency-based via one's unique neuronal mapping as a byproduct of genetics, epigenetics, and experience. (6) Perception involves information intake and information discrimination, equally underpinned by efficiencies of inclusive fitness via extreme thrownness. Perception is not a 'frame rate' but Bayesian priors of efficiency based on one's extreme thrownness. (7) Consciousness and human consciousness are modular (i.e., a scalar level of richness, which builds up like building blocks) and dimensionalized (i.e., cognitive abilities become possibilities as the emergent phenomena at various modularities such as the stratified factors in factor analysis). (8) The meta dimensions of human consciousness seemingly include intelligence quotient, personality (five-factor model), richness of perception intake, and richness of perception discrimination, among other potentialities. (9) Future consciousness research should utilize factor analysis to parse modularities and dimensions of human consciousness and animal models.}, }
@article {pmid38657758, year = {2024}, author = {Kobayashi, Y and Ueno, M}, title = {Proximity and preening in captive Humboldt penguins.}, journal = {Behavioural processes}, volume = {218}, number = {}, pages = {105032}, doi = {10.1016/j.beproc.2024.105032}, pmid = {38657758}, issn = {1872-8308}, mesh = {Animals ; *Spheniscidae/physiology ; *Social Behavior ; *Grooming/physiology ; Male ; *Animals, Zoo ; Female ; Behavior, Animal/physiology ; }, abstract = {Group-living animals, including penguins, exhibit affiliative behaviors such as grooming (preening) and proximity. Such behaviors in non-primate animals have been less studied than those in primates. Our research focused on 20 identifiable Humboldt penguins in a zoo, analyzing kin relationships and reciprocity in preening and proximity by employing a 5-minute scan sampling method to observe and record individual behavior. Our findings revealed that preening and proximity were more prevalent among mate pairs. However, among non-mate pairs, such behaviors were more commonly observed between siblings and parent-offspring pairs. Notably, the individuals preened on each other simultaneously in all instances. This study highlights the potential influence of kin selection in shaping the affiliative behavior of penguins. Additionally, our findings indicate that penguins gain benefits from mutual preening. This study contributes to our understanding of social behaviors in non-primate species and emphasizes the need for further comparative studies of various animal taxa to elucidate the evolution of sociality.}, }
@article {pmid38577983, year = {2024}, author = {West, SA and Griffin, AS}, title = {Microbial Primer: Cooperation in bacteria.}, journal = {Microbiology (Reading, England)}, volume = {170}, number = {4}, pages = {}, doi = {10.1099/mic.0.001440}, pmid = {38577983}, issn = {1465-2080}, mesh = {*Cooperative Behavior ; *Altruism ; Biological Evolution ; Bacteria/genetics ; }, abstract = {The growth and success of many bacteria appear to rely on a stunning range of cooperative behaviours. But what is cooperation and how is it studied?}, }
@article {pmid38560219, year = {2024}, author = {Yang, J and Wang, Y and El Wakil, A and Moussian, B}, title = {Extra-corporeal detoxification in insects.}, journal = {Heliyon}, volume = {10}, number = {7}, pages = {e28392}, pmid = {38560219}, issn = {2405-8440}, abstract = {Upon uptake of toxins, insects launch a detoxification program. This program is deployed in multiple organs and cells to raise their tolerance against the toxin. The molecular mechanisms of this program inside the insect body have been studied and understood in detail. Here, we report on a yet unexplored extra-corporeal detoxification of insecticides in Drosophila melanogaster. Wild-type D. melanogaster incubated with DDT, a contact insecticide, in a closed environment died as expected. However, incubation of a second cohort in the same environment after removal of the dead flies was not lethal. The effect was significantly lower if the flies of the two cohorts were unrelated. Incubation assays with Chlorpyrifos, another contact insecticide, yielded identical results, while incubation assays with Chlorantraniliprole, again a contact insecticide, was toxic for the second cohort of flies. A cohort of flies incubated in a DDT environment after an initial incubation of a honeybee survived treatment. Together, our data suggest that insects including Apis mellifera and D. melanogaster have the capacity to modify their proximate environment. Consequently, in their ecological niche, following individuals might be saved from intoxication thereby facilitating colonisation of an attractive site.}, }
@article {pmid38492917, year = {2024}, author = {McGrane-Corrigan, B and Mason, O and de Andrade Moral, R}, title = {Inferring stochastic group interactions within structured populations via coupled autoregression.}, journal = {Journal of theoretical biology}, volume = {584}, number = {}, pages = {111793}, doi = {10.1016/j.jtbi.2024.111793}, pmid = {38492917}, issn = {1095-8541}, mesh = {Animals ; *Ecosystem ; Population Dynamics ; Bayes Theorem ; *Predatory Behavior ; Models, Biological ; Group Dynamics ; Food Chain ; }, abstract = {The internal behaviour of a population is an important feature to take account of when modelling its dynamics. In line with kin selection theory, many social species tend to cluster into distinct groups in order to enhance their overall population fitness. Temporal interactions between populations are often modelled using classical mathematical models, but these sometimes fail to delve deeper into the, often uncertain, relationships within populations. Here, we introduce a stochastic framework that aims to capture the interactions of animal groups and an auxiliary population over time. We demonstrate the model's capabilities, from a Bayesian perspective, through simulation studies and by fitting it to predator-prey count time series data. We then derive an approximation to the group correlation structure within such a population, while also taking account of the effect of the auxiliary population. We finally discuss how this approximation can lead to ecologically realistic interpretations in a predator-prey context. This approximation also serves as verification to whether the population in question satisfies our various assumptions. Our modelling approach will be useful for empiricists for monitoring groups within a conservation framework and also theoreticians wanting to quantify interactions, to study cooperation and other phenomena within social populations.}, }
@article {pmid38477032, year = {2024}, author = {Fromhage, L and Jennions, MD and Myllymaa, L and Henshaw, JM}, title = {Fitness as the organismal performance measure guiding adaptive evolution.}, journal = {Evolution; international journal of organic evolution}, volume = {78}, number = {6}, pages = {1039-1053}, doi = {10.1093/evolut/qpae043}, pmid = {38477032}, issn = {1558-5646}, support = {456626331//Bundesministerium f&#xfc;r Bildung und Forschung and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)/ ; 340130//Research Council of Finland/ ; }, mesh = {*Genetic Fitness ; *Selection, Genetic ; *Biological Evolution ; Adaptation, Biological ; Animals ; Models, Genetic ; Phenotype ; Adaptation, Physiological/genetics ; }, abstract = {A long-standing problem in evolutionary theory is to clarify in what sense (if any) natural selection cumulatively improves the design of organisms. Various concepts, such as fitness and inclusive fitness, have been proposed to resolve this problem. In addition, there have been attempts to replace the original problem with more tractable questions, such as whether a given gene or trait is favored by selection. Here, we ask what theoretical properties the concept fitness should possess to encapsulate the improvement criterion required to talk meaningfully about adaptive evolution. We argue that natural selection tends to shape phenotypes based on the causal properties of individuals and that this tendency is, therefore, best captured by a fitness concept that focuses on these properties. We highlight a fitness concept that meets this role under broad conditions but requires adjustments in our conceptual understanding of adaptive evolution. These adjustments combine elements of Dawkinsian gene selectionism and Egbert Leigh's "parliament of genes."}, }
@article {pmid38471475, year = {2024}, author = {Schradin, C and Jaeggi, AV and Criscuolo, F}, title = {Quick Guide to Evolutionary Medicine in Neuroimmunomodulation: Why "Evolved for the Benefit of the Species" Is Not a Valid Argument.}, journal = {Neuroimmunomodulation}, volume = {31}, number = {1}, pages = {66-77}, doi = {10.1159/000538294}, pmid = {38471475}, issn = {1423-0216}, mesh = {Humans ; *Biological Evolution ; *Neuroimmunomodulation/physiology ; Animals ; Phylogeny ; Selection, Genetic ; }, abstract = {BACKGROUND: Evolutionary medicine builds on evolutionary biology and explains why natural selection has left us vulnerable to disease. Unfortunately, several misunderstandings exist in the medical literature about the levels and mechanisms of evolution. Reasons for these problems start from the lack of teaching evolutionary biology in medical schools. A common mistake is to assume that "traits must benefit the species, as otherwise the species would have gone extinct in the past" confusing evolutionary history (phylogeny) with evolutionary function (fitness).<br><br>SUMMARY: Here we summarise some basic aspects of evolutionary medicine by pointing out: (1) Evolution has no aim. (2) For adaptive evolution to occur, a trait does not have to be beneficial to its carrier throughout its entire life. (3) Not every single individual carrying an adaptive trait needs to have higher than average fitness. (4) Traits do not evolve for the benefit of the species. Using examples from the field of neuroimmunomodulation like sickness behaviour (nervous system), testosterone (hormones), and cytokines (immunity), we show how misconceptions arise from not differentiating between the explanatory categories of phylogeny (evolutionary history) and evolutionary function (fitness).<br><br>KEY MESSAGES: Evolution has no aim but is an automatism that does not function for the benefit of the species. In evolution, successful individuals are those that maximise the transmission of their genes, and health and survival are just strategies to have the opportunity to do so. Thus, a trait enabling survival of the individual until reproductive age will spread even if at later age the same trait leads to disease and death. Natural and sexual selection do not select for traits that benefit the health or happiness of the individual, but for traits that increase inclusive fitness even if this increases human suffering. In contrast, our humane aim is to increase individual well-being. Evolutionary medicine can help us achieve this aim against evolutionary constraints.}, }
@article {pmid38462458, year = {2023}, author = {Libertini, G}, title = {Phenoptosis and the Various Types of Natural Selection.}, journal = {Biochemistry. Biokhimiia}, volume = {88}, number = {12}, pages = {2007-2022}, doi = {10.1134/S0006297923120052}, pmid = {38462458}, issn = {1608-3040}, mesh = {Animals ; Bees ; *Aging/genetics ; Ecosystem ; Selection, Genetic ; *Ants ; Reproduction ; Biological Evolution ; }, abstract = {In the first description of evolution, the fundamental mechanism is the natural selection favoring the individuals best suited for survival and reproduction (selection at the individual level or classical Darwinian selection). However, this is a very reductive description of natural selection that does not consider or explain a long series of known phenomena, including those in which an individual sacrifices or jeopardizes his life on the basis of genetically determined mechanisms (i.e., phenoptosis). In fact, in addition to (i) selection at the individual level, it is essential to consider other types of natural selection such as those concerning: (ii) kin selection and some related forms of group selection; (iii) the interactions between the innumerable species that constitute a holobiont; (iv) the origin of the eukaryotic cell from prokaryotic organisms; (v) the origin of multicellular eukaryotic organisms from unicellular organisms; (vi) eusociality (e.g., in many species of ants, bees, termites); (vii) selection at the level of single genes, or groups of genes; (viii) the interactions between individuals (or more precisely their holobionts) of the innumerable species that make up an ecosystem. These forms of natural selection, which are all effects and not violations of the classical Darwinian selection, also show how concepts as life, species, individual, and phenoptosis are somewhat not entirely defined and somehow arbitrary. Furthermore, the idea of organisms selected on the basis of their survival and reproduction capabilities is intertwined with that of organisms also selected on the basis of their ability to cooperate and interact, even by losing their lives or their distinct identities.}, }
@article {pmid38443305, year = {2024}, author = {Erler, S and Cotter, SC and Freitak, D and Koch, H and Palmer-Young, EC and de Roode, JC and Smilanich, AM and Lattorff, HMG}, title = {Insects' essential role in understanding and broadening animal medication.}, journal = {Trends in parasitology}, volume = {40}, number = {4}, pages = {338-349}, doi = {10.1016/j.pt.2024.02.003}, pmid = {38443305}, issn = {1471-5007}, mesh = {Animals ; Humans ; *Insecta ; *Parasites ; Reproduction ; Host-Parasite Interactions ; }, abstract = {Like humans, animals use plants and other materials as medication against parasites. Recent decades have shown that the study of insects can greatly advance our understanding of medication behaviors. The ease of rearing insects under laboratory conditions has enabled controlled experiments to test critical hypotheses, while their spectrum of reproductive strategies and living arrangements - ranging from solitary to eusocial communities - has revealed that medication behaviors can evolve to maximize inclusive fitness through both direct and indirect fitness benefits. Studying insects has also demonstrated in some cases that medication can act through modulation of the host's innate immune system and microbiome. We highlight outstanding questions, focusing on costs and benefits in the context of inclusive host fitness.}, }
@article {pmid38420213, year = {2024}, author = {Kemp, JT and Kline, AG and Bettencourt, LMA}, title = {Information synergy maximizes the growth rate of heterogeneous groups.}, journal = {PNAS nexus}, volume = {3}, number = {2}, pages = {pgae072}, pmid = {38420213}, issn = {2752-6542}, support = {R01 EB026943/EB/NIBIB NIH HHS/United States ; }, abstract = {Collective action and group formation are fundamental behaviors among both organisms cooperating to maximize their fitness and people forming socioeconomic organizations. Researchers have extensively explored social interaction structures via game theory and homophilic linkages, such as kin selection and scalar stress, to understand emergent cooperation in complex systems. However, we still lack a general theory capable of predicting how agents benefit from heterogeneous preferences, joint information, or skill complementarities in statistical environments. Here, we derive general statistical dynamics for the origin of cooperation based on the management of resources and pooled information. Specifically, we show how groups that optimally combine complementary agent knowledge about resources in statistical environments maximize their growth rate. We show that these advantages are quantified by the information synergy embedded in the conditional probability of environmental states given agents' signals, such that groups with a greater diversity of signals maximize their collective information. It follows that, when constraints are placed on group formation, agents must intelligently select with whom they cooperate to maximize the synergy available to their own signal. Our results show how the general properties of information underlie the optimal collective formation and dynamics of groups of heterogeneous agents across social and biological phenomena.}, }
@article {pmid38417560, year = {2024}, author = {Flatrès, A and Wild, G}, title = {Evolution of delayed dispersal with group size effect and population dynamics.}, journal = {Theoretical population biology}, volume = {157}, number = {}, pages = {1-13}, doi = {10.1016/j.tpb.2024.02.007}, pmid = {38417560}, issn = {1096-0325}, mesh = {*Population Dynamics ; Animals ; Biological Evolution ; Population Density ; Fertility ; Social Behavior ; Reproduction ; }, abstract = {Individuals delay natal dispersal for many reasons. There may be no place to disperse to; immediate dispersal or reproduction may be too costly; immediate dispersal may mean that the individual and their relatives miss the benefits of group living. Understanding the factors that lead to the evolution of delayed dispersal is important because delayed dispersal sets the stage for complex social groups and social behavior. Here, we study the evolution of delayed dispersal when the quality of the local environment is improved by greater numbers of individuals (e.g., safety in numbers). We assume that individuals who delay natal dispersal also expect to delay personal reproduction. In addition, we assume that improved environmental quality benefits manifest as changes to fecundity and survival. We are interested in how do the changes in these life-history features affect delayed dispersal. We use a model that ties evolution to population dynamics. We also aim to understand the relationship between levels of delayed dispersal and the probability of establishing as an independent breeder (a population-level feature) in response to changes in life-history details. Our model emphasizes kin selection and considers a sexual organism, which allows us to study parent-offspring conflict over delayed dispersal. At evolutionary equilibrium, fecundity and survival benefits of group size or quality promote higher levels of delayed dispersal over a larger set of life histories with one exception. The exception is for benefits of increased group size or quality reaped by the individuals who delay dispersal. There, the increased benefit does not change the life histories supporting delay dispersal. Next, in contrast to previous predictions, we find that a low probability of establishing in a new location is not always associated with a higher incidence of delayed dispersal. Finally, we find that increased personal benefits of delayed dispersal exacerbate the conflict between parents and their offspring. We discuss our findings in relation to previous theoretical and empirical work, especially work related to cooperative breeding.}, }
@article {pmid38412971, year = {2024}, author = {Dewar, AE and Belcher, LJ and Scott, TW and West, SA}, title = {Genes for cooperation are not more likely to be carried by plasmids.}, journal = {Proceedings. Biological sciences}, volume = {291}, number = {2017}, pages = {20232549}, pmid = {38412971}, issn = {1471-2954}, mesh = {Plasmids/genetics ; *Genome, Bacterial ; *Bacteria/genetics ; Genomics ; Gene Transfer, Horizontal ; }, abstract = {Cooperation is prevalent across bacteria, but risks being exploited by non-cooperative cheats. Horizontal gene transfer, particularly via plasmids, has been suggested as a mechanism to stabilize cooperation. A key prediction of this hypothesis is that genes which are more likely to be transferred, such as those on plasmids, should be more likely to code for cooperative traits. Testing this prediction requires identifying all genes for cooperation in bacterial genomes. However, previous studies used a method which likely misses some of these genes for cooperation. To solve this, we used a new genomics tool, SOCfinder, which uses three distinct modules to identify all kinds of genes for cooperation. We compared where these genes were located across 4648 genomes from 146 bacterial species. In contrast to the prediction of the hypothesis, we found no evidence that plasmid genes are more likely to code for cooperative traits. Instead, we found the opposite-that genes for cooperation were more likely to be carried on chromosomes. Overall, the vast majority of genes for cooperation are not located on plasmids, suggesting that the more general mechanism of kin selection is sufficient to explain the prevalence of cooperation across bacteria.}, }
@article {pmid38409256, year = {2024}, author = {Galdino, ACM and Vaillancourt, M and Celedonio, D and Huse, K and Doi, Y and Lee, JS and Jorth, P}, title = {Siderophores promote cooperative interspecies and intraspecies cross-protection against antibiotics in vitro.}, journal = {Nature microbiology}, volume = {9}, number = {3}, pages = {631-646}, pmid = {38409256}, issn = {2058-5276}, support = {JORTH19P0//Cystic Fibrosis Foundation (CF Foundation)/ ; K22 AI127473/AI/NIAID NIH HHS/United States ; R01 AI146425/AI/NIAID NIH HHS/United States ; R01Hl136143//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; R01 HL136143/HL/NHLBI NIH HHS/United States ; R01AI14642//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; R21 AI151362/AI/NIAID NIH HHS/United States ; JORTH17F5//Cystic Fibrosis Foundation (CF Foundation)/ ; MILESI21F0//Cystic Fibrosis Foundation (CF Foundation)/ ; R21AI151362//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; K22AI127473//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; }, mesh = {Humans ; *Anti-Bacterial Agents/pharmacology/metabolism ; *Siderophores/metabolism/pharmacology ; Cefiderocol ; Iron/metabolism ; Enterobacteriaceae/metabolism ; Pseudomonas aeruginosa/metabolism ; }, abstract = {The antibiotic cefiderocol hijacks iron transporters to facilitate its uptake and resists β-lactamase degradation. While effective, resistance has been detected clinically with unknown mechanisms. Here, using experimental evolution, we identified cefiderocol resistance mutations in Pseudomonas aeruginosa. Resistance was multifactorial in host-mimicking growth media, led to multidrug resistance and paid fitness costs in cefiderocol-free environments. However, kin selection drove some resistant populations to cross-protect susceptible individuals from killing by increasing pyoverdine secretion via a two-component sensor mutation. While pyochelin sensitized P. aeruginosa to cefiderocol killing, pyoverdine and the enterobacteria siderophore enterobactin displaced iron from cefiderocol, preventing uptake by susceptible cells. Among 113 P. aeruginosa intensive care unit clinical isolates, pyoverdine production directly correlated with cefiderocol tolerance, and high pyoverdine producing isolates cross-protected susceptible P. aeruginosa and other Gram-negative bacteria. These in vitro data show that antibiotic cross-protection can occur via degradation-independent mechanisms and siderophores can serve unexpected protective cooperative roles in polymicrobial communities.}, }
@article {pmid38403933, year = {2024}, author = {Montazeaud, G and Keller, L}, title = {Greenbeards in plants?.}, journal = {The New phytologist}, volume = {242}, number = {3}, pages = {870-877}, doi = {10.1111/nph.19599}, pmid = {38403933}, issn = {1469-8137}, support = {101030712//HORIZON EUROPE Marie Sklodowska-Curie Actions/ ; }, abstract = {Greenbeards are selfish genetic elements that make their bearers behave either altruistically towards individuals bearing similar greenbeard copies or harmfully towards individuals bearing different copies. They were first proposed by W. D. Hamilton over 50 yr ago, to illustrate that kin selection may operate at the level of single genes. Examples of greenbeards have now been reported in a wide range of taxa, but they remain undocumented in plants. In this paper, we discuss the theoretical likelihood of greenbeard existence in plants. We then question why the greenbeard concept has never been applied to plants and speculate on how hypothetical greenbeards could affect plant-plant interactions. Finally, we point to different research directions to improve our knowledge of greenbeards in plants.}, }
@article {pmid38371869, year = {2024}, author = {Thomson, L and Espinosa, DP and Brandvain, Y and Van Cleve, J}, title = {Linked selection and the evolution of altruism in family-structured populations.}, journal = {Ecology and evolution}, volume = {14}, number = {2}, pages = {e10980}, pmid = {38371869}, issn = {2045-7758}, abstract = {Much research on the evolution of altruism via kin selection, group selection, and reciprocity focuses on the role of a single locus or quantitative trait. Very few studies have explored how linked selection, or selection at loci neighboring an altruism locus, impacts the evolution of altruism. While linked selection can decrease the efficacy of selection at neighboring loci, it might have other effects including promoting selection for altruism by increasing relatedness in regions of low recombination. Here, we used population genetic simulations to study how negative selection at linked loci, or background selection, affects the evolution of altruism. When altruism occurs between full siblings, we found that background selection interfered with selection on the altruistic allele, increasing its fixation probability when the altruistic allele was disfavored and reducing its fixation when the allele was favored. In other words, background selection has the same effect on altruistic genes in family-structured populations as it does on other, nonsocial, genes. This contrasts with prior research showing that linked selective sweeps can favor the evolution of cooperation, and we discuss possibilities for resolving these contrasting results.}, }
@article {pmid38368855, year = {2024}, author = {Crespi, BJ}, title = {The Roots of Science, Technology, Engineering, and Mathematics: What Are the Evolutionary and Neural Bases of Human Mathematics and Technology?.}, journal = {Brain, behavior and evolution}, volume = {99}, number = {1}, pages = {1-12}, doi = {10.1159/000537908}, pmid = {38368855}, issn = {1421-9743}, mesh = {Animals ; Humans ; Biological Evolution ; *Brain/physiology/anatomy &amp; histology ; Cognition/physiology ; *Engineering ; *Mathematics ; *Science ; *Technology ; }, abstract = {INTRODUCTION: Neural exaptations represent descent via transitions to novel neural functions. A primary transition in human cognitive and neural evolution was from a predominantly socially oriented primate brain to a brain that also instantiates and subserves science, technology, and engineering, all of which depend on mathematics. Upon what neural substrates and upon what evolved cognitive mechanisms did human capacities for science, technology, engineering, and mathematics (STEM), and especially its mathematical underpinnings, emerge? Previous theory focuses on roles for tools, language, and arithmetic in the cognitive origins of STEM, but none of these factors appears sufficient to support the transition.<br><br>METHODS: In this article, I describe and evaluate a novel hypothesis for the neural origins and substrates of STEM-based cognition: that they are based in human kinship systems and human maximizing of inclusive fitness.<br><br>RESULTS: The main evidence for this hypothesis is threefold. First, as demonstrated by anthropologists, human kinship systems exhibit complex mathematical and geometrical structures that function under sets of explicit rules, and such systems and rules pervade and organize all human cultures. Second, human kinship underlies the core algebraic mechanism of evolution, maximization of inclusive fitness, quantified as personal reproduction plus the sum of all effects on reproduction of others, each multiplied by their coefficient of relatedness to self. This is the only "natural" equation expected to be represented in the human brain. Third, functional imaging studies show that kinship-related cognition activates frontal-parietal regions that are also activated in STEM-related tasks. In turn, the decision-making that integrates kinship levels with costs and benefits from alternative behaviors has recently been shown to recruit the lateral septum, a hub region that combines internal (from the prefrontal cortex, amygdala, and other regions) and external information relevant to social behavior, using a dedicated subsystem of neurons specific to kinship.<br><br>CONCLUSIONS: Taken together, these lines of evidence suggest that kinship systems and kin-associated behaviors may represent exaptations for the origin of human STEM.}, }
@article {pmid38358814, year = {2024}, author = {Kerr, NZ and Morris, WF and Walters, JR}, title = {Inclusive Fitness May Explain Some but Not All Benefits Derived from Helping Behavior in a Cooperatively Breeding Bird.}, journal = {The American naturalist}, volume = {203}, number = {3}, pages = {393-410}, doi = {10.1086/728670}, pmid = {38358814}, issn = {1537-5323}, mesh = {Animals ; Male ; *Helping Behavior ; *Cooperative Behavior ; Birds ; Reproduction ; }, abstract = {AbstractIn cooperative breeding systems, inclusive fitness theory predicts that nonbreeding helpers more closely related to the breeders should be more willing to provide costly alloparental care and thus have more impact on breeder fitness. In the red-cockaded woodpecker (Dryobates borealis), most helpers are the breeders' earlier offspring, but helpers do vary within groups in both relatedness to the breeders (some even being unrelated) and sex, and it can be difficult to parse their separate impacts on breeder fitness. Moreover, most support for inclusive fitness theory has been positive associations between relatedness and behavior rather than actual fitness consequences. We used functional linear models to evaluate the per capita effects of helpers of different relatedness on eight breeder fitness components measured for up to 41 years at three sites. In support of inclusive fitness theory, helpers more related to the breeding pair made greater contributions to six fitness components. However, male helpers made equal contributions to increasing prefledging survival regardless of relatedness. These findings suggest that both inclusive fitness benefits and other direct benefits may underlie helping behaviors in the red-cockaded woodpecker. Our results also demonstrate the application of an underused statistical approach to disentangle a complex ecological phenomenon.}, }
@article {pmid38353866, year = {2024}, author = {Waynforth, D}, title = {Alloparental Support and Infant Psychomotor Developmental Delay.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {35}, number = {1}, pages = {43-62}, pmid = {38353866}, issn = {1936-4776}, mesh = {Humans ; Infant ; *Developmental Disabilities ; Female ; *Social Support ; Male ; United Kingdom ; Mothers/psychology ; Child Development/physiology ; Adult ; Infant Care ; }, abstract = {Receiving social support from community and extended family has been typical for mothers with infants in human societies past and present. In non-industrialised contexts, infants of mothers with extended family support often have better health and higher survival through the vulnerable infant period, and hence shared infant care has a clear fitness benefit. However, there is scant evidence that these benefits continue in industrialised contexts. Better infant health and development with allocare support would indicate continued evolutionary selection for allocare. The research reported here used multiple logistic regression analysis to test whether a lack of family and other social support for mothers was associated with an increased risk of developmental delay in 9-month-old infants in the UK Millennium Cohort (analysis sample size, 15,696 infants). Extended family-based childcare during work hours and more maternal time spent with friends were the most influential kin and social support variables: infants of mothers with kin-based childcare versus all other childcare arrangements had a lower risk of developmental delay (OR = 0.61, 95% CIs: 0.46-0.82). Infants of mothers who spent no time with friends when compared with those who saw friends every day had double the odds of delay. Greater paternal involvement in infant care was associated with a lower odds of developmental delay. In conclusion, shared care of infants and social support for mothers may influence fitness-related traits in industrialised societies rather than being factors that influenced selection only in the past and in societies which retain close kin networks and a strong local community focus.}, }
@article {pmid38350872, year = {2024}, author = {Araujo, NS and Ogihara, F and Martins, PM and Arias, MC}, title = {Insights from Melipona bicolor hybrid genome assembly: a stingless bee genome with chromosome-level scaffold.}, journal = {BMC genomics}, volume = {25}, number = {1}, pages = {171}, pmid = {38350872}, issn = {1471-2164}, support = {2019/23186-9; 2016/24669-5//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; 2019/23186-9; 2016/24669-5//Funda&#xe7;&#xe3;o de Amparo &#xe0; Pesquisa do Estado de S&#xe3;o Paulo/ ; 40005980//Fonds De La Recherche Scientifique - FNRS/ ; 307356/2019-1//Conselho Nacional de Desenvolvimento Cient&#xed;fico e Tecnol&#xf3;gico/ ; }, mesh = {Bees/genetics ; Animals ; *Ecosystem ; *Social Behavior ; Reproduction ; Chromosomes/genetics ; }, abstract = {BACKGROUND: The highly eusocial stingless bees are crucial pollinators of native and agricultural ecosystems. Nevertheless, genomic studies within this bee tribe remain scarce. We present the genome assembly of the stingless bee Melipona bicolor. This bee is a remarkable exception to the typical single-queen colony structure, since in this species, multiple queens may coexist and share reproductive duties, resulting in genetically diverse colonies with weak kinship connections. As the only known genuinely polygynous bee, M. bicolor's genome provides a valuable resource for investigating sociality beyond kin selection.<br><br>RESULTS: The genome was assembled employing a hybrid approach combining short and long reads, resulting in 241 contigs spanning 259&#xa0;Mb (N50 of 6.2&#xa0;Mb and 97.5% complete BUSCOs). Comparative analyses shed light on some evolutionary aspects of stingless bee genomics, including multiple chromosomal rearrangements in Melipona. Additionally, we explored the evolution of venom genes in M. bicolor and other stingless bees, revealing that, apart from two genes, the conserved repertoire of venom components remains under purifying selection in this clade.<br><br>CONCLUSION: This study advances our understanding of stingless bee genomics, contributing to the conservation efforts of these vital pollinators and offering insights into the evolutionary mechanisms driving their unique adaptations.}, }
@article {pmid38309717, year = {2024}, author = {Downing, PA}, title = {Michener's group-size paradox in cooperatively breeding birds.}, journal = {Journal of evolutionary biology}, volume = {37}, number = {3}, pages = {353-359}, doi = {10.1093/jeb/voae008}, pmid = {38309717}, issn = {1420-9101}, support = {//University of Oulu/ ; 336449//Academy of Finland/ ; }, mesh = {Humans ; Animals ; *Altruism ; *Birds ; Breeding ; Head ; Reproduction ; }, abstract = {According to Michener's paradox, most altruistic groups in nature should be small and large groups should not exist. This is because per capita productivity is thought to decrease as groups get larger, meaning that the share of indirect fitness available to each group member declines, which favours dispersal. The empirical evidence for a decrease in per capita productivity is contradictory, however, and limited to the social Hymenoptera. I report that per capita reproductive success decreased with increasing group size across 26 cooperatively breeding bird species. Small groups comprising two or three individuals were the most common (79% of 16,101 groups), and these had the highest per capita reproductive success. This close fit between per capita reproductive success and the distribution of group sizes in nature suggests that it may indeed be difficult for large groups to evolve through indirect fitness benefits alone.}, }
@article {pmid38274864, year = {2024}, author = {Schroeder, JL and Worm, AJ and Sweet, AD and Rolland, V}, title = {Genomic data reveal unexpected relatedness between a brown female Eastern Bluebird and her brood.}, journal = {Ecology and evolution}, volume = {14}, number = {1}, pages = {e10851}, pmid = {38274864}, issn = {2045-7758}, abstract = {Because plumage coloration is frequently involved in sexual selection, for both male and female mate choice, birds with aberrant plumage should have fewer mating opportunities and thus lower reproductive output. Here we report an Eastern Bluebird (Sialia sialis) female with a brown phenotype that raised a brood of four chicks to fledging. The brown female and her mate were only related to their social offspring to the second degree and one of the offspring was a half-sibling. We propose four family tree scenarios and discuss their implications (e.g., extra-pair paternity, conspecific brood parasitism). Regardless of the tree, the brown female was able to find a mate, which may have been facilitated by the bottleneck created by the severe snowstorms in February 2021.}, }
@article {pmid38267842, year = {2024}, author = {Chapman, H and Hsiung, KC and Rawlinson, I and Galimov, ER and Gems, D}, title = {Colony level fitness analysis identifies a trade-off between population growth rate and dauer yield in Caenorhabditis elegans.}, journal = {BMC ecology and evolution}, volume = {24}, number = {1}, pages = {13}, pmid = {38267842}, issn = {2730-7182}, mesh = {Animals ; *Caenorhabditis elegans ; *Population Growth ; Apoptosis ; Benchmarking ; Biological Assay ; }, abstract = {BACKGROUND: In the evolution from unicellular to multicellular life forms, natural selection favored reduced cell proliferation and even programmed cell death if this increased organismal fitness. Could reduced individual fertility or even programmed organismal death similarly increase the fitness of colonies of closely-related metazoan organisms? This possibility is at least consistent with evolutionary theory, and has been supported by computer modelling. Caenorhabditis elegans has a boom and bust life history, where populations of nematodes that are sometimes near clonal subsist on and consume food patches, and then generate dauer larva dispersal propagules. A recent study of an in silico model of C. elegans predicted that one determinant of colony fitness (measured as dauer yield) is minimization of futile food consumption (i.e. that which does not contribute to dauer yield). One way to achieve this is to optimize colony population structure by adjustment of individual fertility.<br><br>RESULTS: Here we describe development of a C. elegans colony fitness assay, and its use to investigate the effect of altering population structure on colony fitness after population bust. Fitness metrics measured were speed of dauer production, and dauer yield, an indirect measure of efficiency of resource utilization (i.e. conversion of food into dauers). We find that with increasing founder number, speed of dauer production increases (due to earlier bust) but dauer yield rises and falls. In addition, some dauer recovery was detected soon after the post-colony bust peak of dauer yield, suggesting possible bet hedging among dauers.<br><br>CONCLUSIONS: These results suggest the presence of a fitness trade-off at colony level between speed and efficiency of resource utilization in C. elegans. They also provide indirect evidence that population structure is a determinant of colony level fitness, potentially by affecting level of futile food consumption.}, }
@article {pmid38246487, year = {2024}, author = {Scott, TW}, title = {Crozier's paradox and kin recognition: Insights from simplified models.}, journal = {Journal of theoretical biology}, volume = {581}, number = {}, pages = {111735}, doi = {10.1016/j.jtbi.2024.111735}, pmid = {38246487}, issn = {1095-8541}, mesh = {*Genetics, Population ; *Biological Evolution ; Altruism ; }, abstract = {Crozier's paradox suggests that genetic kin recognition will not be evolutionarily stable. The problem is that more common tags (markers) are more likely to be recognised and helped. This causes common tags to increase in frequency, eliminating the genetic variability that is required for genetic kin recognition. In recent years, theoretical models have resolved Crozier's paradox in different ways, but they are based on very complicated multi-locus population genetics. Consequently, it is hard to see exactly what is going on, and whether different theoretical resolutions of Crozier's paradox lead to different types of kin discrimination. I address this by making unrealistic simplifying assumptions to produce a more tractable and understandable model of Crozier's paradox. I use this to interpret a more complex multi-locus population genetic model where I have not made the same simplifying assumptions. I explain how Crozier's paradox can be resolved, and show that only one known theoretical resolution of Crozier's paradox - multiple social encounters - leads without restrictive assumptions to the type of highly cooperative and reliable form of kin discrimination that we observe in nature. More generally, I show how adopting a methodological approach where complex models are compared with simplified ones can lead to greater understanding and accessibility.}, }
@article {pmid38232110, year = {2024}, author = {Komatsu, H and Kubota, H and Asano, K and Nagai, Y}, title = {Effect of information provision by familial nudging on attitudes toward offshore wind power.}, journal = {PloS one}, volume = {19}, number = {1}, pages = {e0297199}, pmid = {38232110}, issn = {1932-6203}, mesh = {Humans ; *Wind ; *Attitude ; }, abstract = {Offshore wind power (OWP) is a promising way to achieve decarbonization and tackle global climate change, but acceptance by residents is an important issue for site location. Information provision could be a more cost-effective intervention than debates or subsidies, assuming that scientifically correct information alone is insufficient and information design to boost the message effects considering realistic human responses is necessary. Thus, we designed nudging messages to increase acceptance of OWP, using a message framework to moderate risk-averse attitudes by reminding readers of familial support based on insights from kin selection theory from evolutionary psychology. A randomized controlled trial based on an internet survey of more than 4000 responses from the general public was performed to investigate the message effects. The messages significantly moderated the risk-averse attitudes toward OWP by 0.228 on average on a five-point Likert scale, which meant that about 5 people out of 100 changed their attitudes to be safer by 1 point. This suggests that disseminating flyers using nudging messages might be an effective way to increase acceptance. We also extracted responses from those who mentioned fisheries in an open-ended question as an alternative to actual fishers. Responses from this segment were more complex and the message effects were limited compared with those who did not mention fisheries; although the attitudes toward OWP before receiving the messages were safer, reading descriptions for potential risks on fisheries may have unexpectedly led them to focus on the risks of which they were unaware at first. Because information provision based on nudging is effective but just one of a wide variety of political interventions available, practitioners should consider a combination of multiple options instead of using only nudging messages.}, }
@article {pmid38214699, year = {2024}, author = {Pretelli, I and Crittenden, AN and Dounias, E and Friant, S and Koster, J and Kramer, KL and Mangola, SM and Saez, AM and Lew-Levy, S}, title = {Child and adolescent foraging: New directions in evolutionary research.}, journal = {Evolutionary anthropology}, volume = {33}, number = {2}, pages = {e22020}, doi = {10.1002/evan.22020}, pmid = {38214699}, issn = {1520-6505}, support = {ANR-17-EURE-0010//French National Research Agency (ANR)/ ; }, mesh = {Adolescent ; Humans ; Child ; *Feeding Behavior ; }, abstract = {Young children and adolescents in subsistence societies forage for a wide range of resources. They often target child-specific foods, they can be very successful foragers, and they share their produce widely within and outside of their nuclear family. At the same time, while foraging, they face risky situations and are exposed to diseases that can influence their immune development. However, children's foraging has largely been explained in light of their future (adult) behavior. Here, we reinterpret findings from human behavioral ecology, evolutionary medicine and cultural evolution to center foraging children's contributions to life history evolution, community resilience and immune development. We highlight the need to foreground immediate alongside delayed benefits and costs of foraging, including inclusive fitness benefits, when discussing children's food production from an evolutionary perspective. We conclude by recommending that researchers carefully consider children's social and ecological context, develop cross-cultural perspectives, and incorporate children's foraging into Indigenous sovereignty discourse.}, }
@article {pmid38214204, year = {2024}, author = {Qian, C and Wen, C and Guo, X and Yang, X and Wen, X and Ma, T and Wang, C}, title = {Gregariousness in lepidopteran larvae.}, journal = {Insect science}, volume = {}, number = {}, pages = {}, doi = {10.1111/1744-7917.13312}, pmid = {38214204}, issn = {1744-7917}, support = {2022A1515010080//Guangdong Basic and Applied Basic Research Foundation/ ; }, abstract = {The gregarious lifestyle of lepidopteran larvae is diverse and shaped by a complex interplay of ecological and evolutionary factors. Our review showed that the larval-aggregation behavior has been reported in 23 lepidopteran families, indicating multiple evolution of this behavior. Some larvae live in sibling groups throughout all larval instars and even pupation stages, which may result from the kin-selection. In contrast, group fusion may occur among different sibling or foraging groups of larvae and form larger aggregates, and the gregariousness of these species might be driven by the group-selection. While group size and foraging patterns vary greatly across species, it is generally associated with improved larval survivorship and accelerated development. However, the advantages of group living, such as facilitating feeding activities, adjusting the temperature, and defending natural enemies, may diminish along with development, with strong intraspecific competition occurring at later instars, even when food is abundant. Therefore, the group sizes and fission-fusion dynamics of certain gregarious lepidopteran larvae may be a consequence of their cost-benefit balance depending on various biotic and abiotic factors. Trail and aggregation pheromones, silk trails, or body contact contribute to collective movement and group cohesion of gregarious lepidopteran larvae. However, frequent contact among group members may cause the horizontal transmission of pathogens and pesticides, which may bring an integrated pest management strategy controlling gregarious lepidopteran pests.}, }
@article {pmid38207145, year = {2024}, author = {Schmid, M and Rueffler, C and Lehmann, L and Mullon, C}, title = {Resource Variation Within and Between Patches: Where Exploitation Competition, Local Adaptation, and Kin Selection Meet.}, journal = {The American naturalist}, volume = {203}, number = {1}, pages = {E19-E34}, doi = {10.1086/727483}, pmid = {38207145}, issn = {1537-5323}, mesh = {Humans ; Population Dynamics ; *Ecosystem ; *Models, Theoretical ; Genetic Drift ; Polymorphism, Genetic ; Biological Evolution ; Selection, Genetic ; }, abstract = {AbstractIn patch- or habitat-structured populations, different processes can favor adaptive polymorphism at different scales. While spatial heterogeneity can generate spatially disruptive selection favoring variation between patches, local competition can lead to locally disruptive selection promoting variation within patches. So far, almost all theory has studied these two processes in isolation. Here, we use mathematical modeling to investigate how resource variation within and between habitats influences the evolution of variation in a consumer population where individuals compete in finite patches connected by dispersal. We find that locally and spatially disruptive selection typically act in concert, favoring polymorphism under a wider range of conditions than when in isolation. But when patches are small and dispersal between them is low, kin competition inhibits the emergence of polymorphism, especially when the latter is driven by local competition for resources. We further use our model to clarify what comparisons between trait and neutral genetic differentiation (QST/FST comparisons) can tell about the nature of selection. Overall, our results help us understand the interaction between two major drivers of polymorphism: locally and spatially disruptive selection, and how this interaction is modulated by the unavoidable effects of kin selection under limited dispersal.}, }
@article {pmid38161549, year = {2023}, author = {Hayman, J and Fortune, DW}, title = {Sexual Orientation in Twins: Evidence That Human Sexual Identity May Be Determined Five Days Following Fertilization.}, journal = {Cureus}, volume = {15}, number = {12}, pages = {e51346}, pmid = {38161549}, issn = {2168-8184}, abstract = {Human same-sex sexual attraction has been recorded from the beginning of written history. It remains a controversial topic, but recent theories favor prenatal influences. A paradox is the occurrence of same-sex orientation in twins in that there is a higher level of concordance in monozygous twins compared to that in dizygous twins or non-twin siblings. If sexual orientation was entirely genetically determined monozygous twins would be expected to have identical sexual inclinations. Monozygous twins have twice the incidence of sexual concordance in comparison to dizygous twins but a third of these pairs have different sexual identities. An explanation for this disparity may lie in the time an embryo splits to form two separate fetuses. If splitting occurs early in twin development each twin may develop his or her own sexual identity; splitting occurring later results in twins that have the same sexual dispositions. A possible process for such determination may be in the mitochondria, with universal maternal inheritance of a proportion of normal functioning but alternate mitochondria. Variation in the distribution of these mitochondria in neural precursor cells becomes a mechanism for the development of intrinsic sexual orientation and for the spectrum of human sexual inclinations. The timing of embryonic splitting may be determined from the examination of fetal membranes, and the concept of early fetal sexual orientation is open to support or disproval.}, }
@article {pmid38117204, year = {2023}, author = {Belcher, LJ and Dewar, AE and Hao, C and Katz, Z and Ghoul, M and West, SA}, title = {SOCfinder: a genomic tool for identifying social genes in bacteria.}, journal = {Microbial genomics}, volume = {9}, number = {12}, pages = {}, pmid = {38117204}, issn = {2057-5858}, mesh = {*Genomics ; *Bacteria/genetics ; Genes, Bacterial/genetics ; Computational Biology ; Anti-Bacterial Agents ; Pseudomonas aeruginosa ; }, abstract = {Bacteria cooperate by working collaboratively to defend their colonies, share nutrients, and resist antibiotics. Nevertheless, our understanding of these remarkable behaviours primarily comes from studying a few well-characterized species. Consequently, there is a significant gap in our understanding of microbial social traits, particularly in natural environments. To address this gap, we can use bioinformatic tools to identify genes that control cooperative or otherwise social traits. Existing tools address this challenge through two approaches. One approach is to identify genes that encode extracellular proteins, which can provide benefits to neighbouring cells. An alternative approach is to predict gene function using annotation tools. However, these tools have several limitations. Not all extracellular proteins are cooperative, and not all cooperative behaviours are controlled by extracellular proteins. Furthermore, existing functional annotation methods frequently miss known cooperative genes. We introduce SOCfinder as a new tool to find bacterial genes that control cooperative or otherwise social traits. SOCfinder combines information from several methods, considering if a gene is likely to [1] code for an extracellular protein [2], have a cooperative functional annotation, or [3] be part of the biosynthesis of a cooperative secondary metabolite. We use data on two extensively-studied species (P. aeruginosa and B. subtilis) to show that SOCfinder is better at finding known cooperative genes than existing tools. We also use theory from population genetics to identify a signature of kin selection in SOCfinder cooperative genes, which is lacking in genes identified by existing tools. SOCfinder opens up a number of exciting directions for future research, and is available to download from https://github.com/lauriebelch/SOCfinder.}, }
@article {pmid38018113, year = {2023}, author = {Rodrigues, AMM and Gardner, A}, title = {Transmission of social status drives cooperation and offspring philopatry.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2011}, pages = {20231314}, pmid = {38018113}, issn = {1471-2954}, mesh = {Animals ; Humans ; *Biological Evolution ; *Social Status ; Models, Theoretical ; Fertility ; }, abstract = {The evolution of cooperation depends on two crucial overarching factors: relatedness, which describes the extent to which the recipient shares genes in common with the actor; and quality, which describes the recipient's basic capacity to transmit genes into the future. While most research has focused on relatedness, there is a growing interest in understanding how quality modulates the evolution of cooperation. However, the impact of inheritance of quality on the evolution of cooperation remains largely unexplored, especially in spatially structured populations. Here, we develop a mathematical model to understand how inheritance of quality, in the form of social status, influences the evolution of helping and harming within social groups in a viscous-population setting. We find that: (1) status-reversal transmission, whereby parental and offspring status are negatively correlated, strongly inhibits the evolution of cooperation, with low-status individuals investing less in cooperation and high-status individuals being more prone to harm; (2) transmission of high status promotes offspring philopatry, with more cooperation being directed towards the higher-dispersal social class; and (3) fertility inequality and inter-generational status inheritance reduce within-group conflict. Overall, our study highlights the importance of considering different mechanisms of phenotypic inheritance, including social support, and their potential interactions in shaping animal societies.}, }
@article {pmid38016596, year = {2024}, author = {Reynolds-Hogland, M and Brooks, C and Ramsey, AB and Hogland, JS and Pilgrim, KL and Engkjer, C and Ramsey, PW}, title = {Long-term video and genetic data yield insights into complex sociality of a solitary large carnivore.}, journal = {Behavioural processes}, volume = {214}, number = {}, pages = {104972}, doi = {10.1016/j.beproc.2023.104972}, pmid = {38016596}, issn = {1872-8308}, mesh = {Animals ; Female ; Male ; *Ursidae ; Animals, Wild ; Social Behavior ; Reproduction ; Ethology ; }, abstract = {American black bears (Ursus americanus) may be more social than currently understood. We used long-term video and genetic data to evaluate social interactions among wild, independent-aged black bear on a conservation property in western Montana, USA. We used multinomial logistic regression to evaluate predictions about male-male interactions within the context of individual fitness, female-female interactions within the context of inclusive fitness, and male-female interactions within the context of female counterstrategies to infanticide. Overall, our findings challenged the assumption that independent-aged bears interact only during the mating season or when concentrated feeding sites are present. We documented 169 interaction events by at least 66 bear pairs, 92 (54%) of which occurred outside of the peak mating season and in the absence of concentrated feeding sites. The probability that male-male pairs engaged in play and other non-agonistic behaviours was higher than that for female-female pairs. Conversely, the probability that female-female pairs engaged in chase behaviour was higher than that for male-male and male-female pairs. We documented evidence of female mate choice, female resource defense, sexually selected infanticide (SSI), and female counterstrategies to avoid SSI. Our findings improve our understanding of ursid ethology and underscore the complexity of ursid sociality.}, }
@article {pmid37975504, year = {2023}, author = {Alizon, S}, title = {Multiple infection theory rather than 'socio-virology'? A commentary on Leeks et al. 2023.}, journal = {Journal of evolutionary biology}, volume = {36}, number = {11}, pages = {1571-1576}, doi = {10.1111/jeb.14245}, pmid = {37975504}, issn = {1420-9101}, mesh = {*Onions ; *Cooperative Behavior ; Genetic Fitness ; Biological Evolution ; }, }
@article {pmid37969551, year = {2023}, author = {McCormack, JL and Arbuckle, K and Fullard, K and Amos, W and Nichols, HJ}, title = {Lack of intergenerational reproductive conflict, rather than lack of inclusive fitness benefits, explains absence of post-reproductive lifespan in long-finned pilot whales.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {34}, number = {6}, pages = {950-959}, pmid = {37969551}, issn = {1045-2249}, abstract = {Life-history theory suggests that individuals should reproduce until death, yet females of a small number of mammals live for a significant period after ceasing reproduction, a phenomenon known as post-reproductive lifespan. It is thought that the evolution of this trait is facilitated by increasing local relatedness throughout a female's lifetime. This allows older females to gain inclusive fitness through helping their offspring (known as a mother effect) and/or grandoffspring (known as a grandmother effect), rather than gaining direct fitness through reproducing. However, older females may only benefit from stopping reproducing when their direct offspring compete with those of their daughters. Here, we investigate whether a lack of post-reproductive lifespan in long-finned pilot whales (Globicephala melas) results from minimal benefits incurred from the presence of older females, or from a lack of costs resulting from mother-daughter co-reproduction. Using microsatellite data, we conducted parentage analysis on individuals from 25 pods and find that younger females were more likely to have offspring if their mother was present in their pod, indicating that mothers may assist inexperienced daughters to reproduce. However, we found no evidence of reproductive conflict between co-reproducing mothers and daughters, indicating that females may be able to reproduce into old age while simultaneously aiding their daughters in reproduction. This highlights the importance of reproductive conflict in the evolution of a post-reproductive lifespan and demonstrates that mother and grandmother effects alone do not result in the evolution of a post-reproductive lifespan.}, }
@article {pmid37934441, year = {2023}, author = {Liechty, T and Woo, M and Rice, LA and Chiu, CY and Kirkpatrick, S and Hankins, K and Hedgspeth, E and Nichols, A and Porter, C and Smeltzer, M and Adamson, B}, title = {Community Partners' Perspectives on Partnering With an Academic Research Team to Promote Disability-inclusive Fitness Programming.}, journal = {Progress in community health partnerships : research, education, and action}, volume = {17}, number = {3}, pages = {429-437}, pmid = {37934441}, issn = {1557-055X}, mesh = {Humans ; *Community-Based Participatory Research ; *Disabled Persons ; Schools ; Communication ; Exercise ; }, abstract = {BACKGROUND: Community-based fitness programs can support public health by providing access to physical activity opportunities for a vulnerable population with significant barriers. Unfortunately, programs specifically designed for people with disabilities (PWD) and staff training to promote inclusion for PWD in general population programs is limited. The current study aimed to review an on-going partnership that had formed to address this need.<br><br>OBJECTIVES: The purpose of this study was to assess community partners' experiences with a community-academic partnership designed to implement a fitness program for people with multiple sclerosis and also to promote inclusion for PWD in community-based fitness programming.<br><br>METHODS: Semi-structured interviews were conducted with six community partners who had been engaged in a formal partnership with the academic institution for 2 or more years to understand partners' experiences and perspectives about the partnership. Interviews were audio/video recorded, transcribed verbatim, and analyzed thematically.<br><br>RESULTS: Participants described their experiences as falling into four main areas. Pre-partnership experiences (or lack thereof) shaped participants views on entering into academic partnerships. Communication and planning for mutual benefit were key to getting the partnership started. Partners identified challenges and factors for success while they were in the thick of partnership activities. Finally, evaluation allowed for assessment and improvement of the partnership itself and its ultimate goals.<br><br>CONCLUSIONS: Findings suggest that academic-community partnerships can be ideal for promoting inclusion for PWD and highlight insights that can be used in the development of future partnerships.}, }
@article {pmid37926425, year = {2024}, author = {Gardner, A}, title = {A geometric approach to the evolution of altruism.}, journal = {Journal of theoretical biology}, volume = {576}, number = {}, pages = {111653}, doi = {10.1016/j.jtbi.2023.111653}, pmid = {37926425}, issn = {1095-8541}, mesh = {*Altruism ; *Selection, Genetic ; Biological Evolution ; Mathematics ; Probability ; }, abstract = {Fisher's geometric model provides a powerful tool for making predictions about key properties of Darwinian adaptation. Here, I apply the geometric model to predict differences between the evolution of altruistic versus nonsocial phenotypes. I recover Kimura's prediction that probability of fixation is greater for mutations of intermediate size, but I find that the effect size that maximises probability of fixation is relatively small in the context of altruism and relatively large in the context of nonsocial phenotypes, and that the overall probability of fixation is lower for altruism and is higher for nonsocial phenotypes. Accordingly, the first selective substitution is expected to be smaller, and to take longer, in the context of the evolution of altruism. These results strengthen the justification for employing streamlined social evolutionary methodologies that assume adaptations are underpinned by many genes of small effect.}, }
@article {pmid37867189, year = {2023}, author = {Szilágyi, A and Czárán, T and Santos, M and Szathmáry, E}, title = {Directional selection coupled with kin selection favors the establishment of senescence.}, journal = {BMC biology}, volume = {21}, number = {1}, pages = {230}, pmid = {37867189}, issn = {1741-7007}, mesh = {Humans ; *Aging/genetics ; *Longevity ; Mutation ; Reproduction ; Biological Evolution ; Selection, Genetic ; }, abstract = {BACKGROUND: Conventional wisdom in evolutionary theory considers aging as a non-selected byproduct of natural selection. Based on this, conviction aging was regarded as an inevitable phenomenon. It was also thought that in the wild organisms tend to die from diseases, predation and other accidents before they could reach the time when senescence takes its course. Evidence has accumulated, however, that aging is not inevitable and there are organisms that show negative aging even. Furthermore, old age does play a role in the deaths of many different organisms in the wild also. The hypothesis of programmed aging posits that a limited lifespan can evolve as an adaptation (i.e., positively selected for) in its own right, partly because it can enhance evolvability by eliminating "outdated" genotypes. A major shortcoming of this idea is that non-aging sexual individuals that fail to pay the demographic cost of aging would be able to steal good genes by recombination from aging ones.<br><br>RESULTS: Here, we show by a spatially explicit, individual-based simulation model that aging can positively be selected for if a sufficient degree of kin selection complements directional selection. Under such conditions, senescence enhances evolvability because the rate of aging and the rate of recombination play complementary roles. The selected aging rate is highest at zero recombination (clonal reproduction). In our model, increasing extrinsic mortality favors evolved aging by making up free space, thereby decreasing competition and increasing drift, even when selection is stabilizing and the level of aging is set by mutation-selection balance. Importantly, higher extrinsic mortality is not a substitute for evolved aging under directional selection either. Reduction of relatedness decreases the evolved level of aging; chance relatedness favors non-aging genotypes. The applicability of our results depends on empirical values of directional and kin selection in the wild.<br><br>CONCLUSIONS: We found that aging can positively be selected for in a spatially explicit population model when sufficiently strong directional and kin selection prevail, even if reproduction is sexual. The view that there is a conceptual link between giving up clonal reproduction and evolving an aging genotype is supported by computational results.}, }
@article {pmid37829498, year = {2023}, author = {Belcher, LJ and Dewar, AE and Hao, C and Ghoul, M and West, SA}, title = {Signatures of kin selection in a natural population of the bacteria Bacillus subtilis.}, journal = {Evolution letters}, volume = {7}, number = {5}, pages = {315-330}, pmid = {37829498}, issn = {2056-3744}, support = {834164/ERC_/European Research Council/International ; }, abstract = {Laboratory experiments have suggested that bacteria perform a range of cooperative behaviors, which are favored because they are directed toward relatives (kin selection). However, there is a lack of evidence for cooperation and kin selection in natural bacterial populations. Molecular population genetics offers a promising method to study natural populations because the theory predicts that kin selection will lead to relaxed selection, which will result in increased polymorphism and divergence at cooperative genes. Examining a natural population of Bacillus subtilis, we found consistent evidence that putatively cooperative traits have higher polymorphism and greater divergence than putatively private traits expressed at the same rate. In addition, we were able to eliminate alternative explanations for these patterns and found more deleterious mutations in genes controlling putatively cooperative traits. Overall, our results suggest that cooperation is favored by kin selection, with an average relatedness of r = .79 between interacting individuals.}, }
@article {pmid37817595, year = {2023}, author = {Bourke, AFG}, title = {Conflict and conflict resolution in the major transitions.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2008}, pages = {20231420}, pmid = {37817595}, issn = {1471-2954}, mesh = {Humans ; *Negotiating ; *Biological Evolution ; Sexual Behavior ; }, abstract = {Conflict and conflict resolution have been argued to be fundamental to the major transitions in evolution. These were key events in life's history in which previously independently living individuals cooperatively formed a higher-level individual, such as a multicellular organism or eusocial colony. Conflict has its central role because, to proceed stably, the evolution of individuality in each major transition required within-individual conflict to be held in check. This review revisits the role of conflict and conflict resolution in the major transitions, addressing recent work arguing for a minor role. Inclusive fitness logic suggests that differences between the kin structures of clones and sexual families support the absence of conflict at the origin of multicellularity but, by contrast, suggest that key conflicts existed at the origin of eusociality. A principal example is conflict over replacing the founding queen (queen replacement). Following the origin of each transition, conflict remained important, because within-individual conflict potentially disrupts the attainment of maximal individuality (organismality) in the system. The conclusion is that conflict remains central to understanding the major transitions, essentially because conflict arises from differences in inclusive fitness optima while conflict resolution can help the system attain a high degree of coincidence of inclusive fitness interests.}, }
@article {pmid37788701, year = {2023}, author = {Scott, TW and Wild, G}, title = {How to make an inclusive-fitness model.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2008}, pages = {20231310}, pmid = {37788701}, issn = {1471-2954}, mesh = {Humans ; *Biological Evolution ; *Social Behavior ; Altruism ; Reproduction ; Sex Ratio ; Selection, Genetic ; Genetic Fitness ; }, abstract = {Social behaviours are typically modelled using neighbour-modulated fitness, which focuses on individuals having their fitness altered by neighbours. However, these models are either interpreted using inclusive fitness, which focuses on individuals altering the fitness of neighbours, or not interpreted at all. This disconnect leads to interpretational mistakes and obscures the adaptive significance of behaviour. We bridge this gap by presenting a systematic methodology for constructing inclusive-fitness models. We find a behaviour's 'inclusive-fitness effect' by summing primary and secondary deviations in reproductive value. Primary deviations are the immediate result of a social interaction; for example, the cost and benefit of an altruistic act. Secondary deviations are compensatory effects that arise because the total reproductive value of the population is fixed; for example, the increased competition that follows an altruistic act. Compared to neighbour-modulated fitness methodologies, our approach is often simpler and reveals the model's inclusive-fitness narrative clearly. We implement our methodology first in a homogeneous population, with supplementary examples of help under synergy, help in a viscous population and Creel's paradox. We then implement our methodology in a class-structured population, where the advantages of our approach are most evident, with supplementary examples of altruism between age classes, and sex-ratio evolution.}, }
@article {pmid37766488, year = {2023}, author = {Li, Z and Chen, S and Wei, S and Komdeur, J and Lu, X}, title = {Should sons breed independently or help? Local relatedness matters.}, journal = {The Journal of animal ecology}, volume = {92}, number = {11}, pages = {2189-2200}, doi = {10.1111/1365-2656.14005}, pmid = {37766488}, issn = {1365-2656}, mesh = {Humans ; Male ; Animals ; *Nuclear Family ; Social Behavior ; *Passeriformes/genetics ; Breeding ; Reproduction ; Cooperative Behavior ; }, abstract = {In cooperatively breeding birds, why do some individuals breed independently but others have to help at home? This question has been rarely addressed despite its fundamental importance for understanding the evolution of social cooperation. We address it using 15 years of data from Tibetan ground tits Pseudopodoces humilis where helpers consist of younger males. Since whether younger males successfully breed depends critically on their chances to occupy territories nearby home, our analytic strategy is to identify the determinants of individual differences in gaining territory ownership among these ready-to-breed males. Across widowed, last-year helper and yearling males, an age advantage was evident in inheriting resident territories, occupying adjacent vacancies and budding off part of adjacent territories, which left some last-year helpers and most yearling males to take the latter two routes. These males were more likely to acquire a territory if they were genetically related to the previous or current territory owners; otherwise they remained on natal territories as helpers. The relatedness effect can arise from the prior residence advantage established in the preceding winter when younger males followed their parents to perform kin-directed off-territory forays. Our research highlights the key role of local kinship in determining younger males' territory acquisition and thus their fate in terms of independent reproduction versus help. This finding provides insight into the formation of kin-based, facultative cooperative societies prevailing among vertebrates.}, }
@article {pmid37746895, year = {2023}, author = {Bresnahan, ST and Galbraith, D and Ma, R and Anton, K and Rangel, J and Grozinger, CM}, title = {Beyond conflict: Kinship theory of intragenomic conflict predicts individual variation in altruistic behaviour.}, journal = {Molecular ecology}, volume = {32}, number = {21}, pages = {5823-5837}, doi = {10.1111/mec.17145}, pmid = {37746895}, issn = {1365-294X}, support = {DGE1255832//Division of Graduate Education/ ; MCB-0950896//Division of Molecular and Cellular Biosciences/ ; PEN04716//National Institute of Food and Agriculture/ ; }, abstract = {Behavioural variation is essential for animals to adapt to different social and environmental conditions. The Kinship Theory of Intragenomic Conflict (KTIC) predicts that parent-specific alleles can support different behavioural strategies to maximize allele fitness. Previous studies, including in honey bees (Apis mellifera), supported predictions of the KTIC for parent-specific alleles to promote selfish behaviour. Here, we test the KTIC prediction that for altruism-promoting genes (i.e. those that promote behaviours that support the reproductive fitness of kin), the allele with the higher altruism optimum should be selected to be expressed while the other is silenced. In honey bee colonies, workers act altruistically when tending to the queen by performing a 'retinue' behaviour, distributing the queen's mandibular pheromone (QMP) throughout the hive. Workers exposed to QMP do not activate their ovaries, ensuring they care for the queen's brood instead of competing to lay unfertilized eggs. Due to the haplodiploid genetics of honey bees, the KTIC predicts that response to QMP is favoured by the maternal genome. We report evidence for parent-of-origin effects on the retinue response behaviour, ovarian development and gene expression in brains of worker honey bees exposed to QMP, consistent with the KTIC. Additionally, we show enrichment for genes with parent-of-origin expression bias within gene regulatory networks associated with variation in bees' response to QMP. Our study demonstrates that intragenomic conflict can shape diverse social behaviours and influence expression patterns of single genes as well as gene networks.}, }
@article {pmid37700652, year = {2023}, author = {Twyman, KZ and Gardner, A}, title = {Kin selection of time travel: the social evolutionary causes and consequences of dormancy.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2006}, pages = {20231247}, pmid = {37700652}, issn = {1471-2954}, mesh = {Humans ; *Social Evolution ; *Altruism ; Travel ; }, abstract = {A basic mechanism of kin selection is limited dispersal, whereby individuals remain close to their place of origin such that even indiscriminate social interaction tends to modify the fitness of genealogical kin. Accordingly, the causes and consequences of dispersal have received an enormous amount of attention in the social evolution literature. This work has focused on dispersal of individuals in space, yet similar logic should apply to dispersal of individuals in time (e.g. dormancy). We investigate how kin selection drives the evolution of dormancy and how dormancy modulates the evolution of altruism. We recover dormancy analogues of key results that have previously been given for dispersal, showing that: (1) kin selection favours dormancy as a means of relaxing competition between relatives; (2) when individuals may adjust their dormancy behaviour to local density, they are favoured to do so, resulting in greater dormancy in high-density neighbourhoods and a concomitant 'constant non-dormant principle'; (3) when dormancy is constrained to be independent of density, there is no relationship between the rate of dormancy and the evolutionary potential for altruism; and (4) when dormancy is able to evolve in a density-dependent manner, a greater potential for altruism is expected in populations with lower dormancy.}, }
@article {pmid37670147, year = {2023}, author = {Roper, M and Green, JP and Salguero-Gómez, R and Bonsall, MB}, title = {Inclusive fitness forces of selection in an age-structured population.}, journal = {Communications biology}, volume = {6}, number = {1}, pages = {909}, pmid = {37670147}, issn = {2399-3642}, support = {BB/M011224/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Humans ; *Exercise ; Population Dynamics ; *Population Growth ; Reproduction ; }, abstract = {Hamilton's force of selection acting against age-specific mortality is constant and maximal prior to the age of first reproduction, before declining to zero at the age of last reproduction. The force of selection acting on age-specific reproduction declines monotonically from birth in a growing or stationary population. Central to these results is the assumption that individuals do not interact with one another. This assumption is violated in social organisms, where an individual's survival and/or reproduction may shape the inclusive fitness of other group members. Yet, it remains unclear how the forces of selection might be modified when inclusive fitness, rather than population growth rate, is considered the appropriate metric for fitness. Here, we derive such inclusive fitness forces of selection, and show that selection on age-specific survival is not always constant before maturity, and can remain above zero in post-reproductive age classes. We also show how the force of selection on age-specific reproduction does not always decline monotonically from birth, but instead depends on the balance of costs and benefits of increasing reproduction to both direct and indirect fitness. Our theoretical framework provides an opportunity to expand our understanding of senescence across social species.}, }
@article {pmid37667646, year = {2023}, author = {Nonacs, P}, title = {Why do Hymenopteran workers drift to non-natal groups? Generalized reciprocity and the maximization of group and parental success.}, journal = {Journal of evolutionary biology}, volume = {36}, number = {10}, pages = {1365-1374}, doi = {10.1111/jeb.14215}, pmid = {37667646}, issn = {1420-9101}, mesh = {Humans ; Animals ; *Hymenoptera/genetics ; Biological Evolution ; Hybrid Vigor ; Social Behavior ; }, abstract = {Eusocial Hymenoptera are often characterized by having facultatively or obligately sterile worker castes. However, findings across an increasing number of species are that some workers are non-natal-they have 'drifted' away from where they were born and raised. Moreover, drifters are often indistinguishable from natal workers in the work and benefits provided to joined groups. This seems an evolutionary paradox of providing benefits to potentially unrelated individuals over close kin. Rather than being mistakes, drifting is proposed to be adaptive if joiners either gain inclusive fitness by preferentially moving to other kin groups or through generalized reciprocity in which exchanging workers across groups raises group-level genetic diversity and creates social heterosis. It is unclear, however, if reciprocity is unlikely because of a susceptibility to cheating. In resolving this question, a series of evolutionary simulations show: (1) Reciprocity can persist under a range of genetic assumptions and scenarios of cheating, (2) cheating almost always evolves, but can be expressed in a variety of ways that are not always predictable, (3) the inclusive fitness hypothesis is equally or more susceptible to cheating. Moreover, existing data in Hymenoptera (although not extensive) are more consistent with generalized reciprocity. This supports a hypothesis that drifting, as a phenomenon, may more often reflect maximization of group and parental fitness rather than fitness gains for the individual drifters.}, }
@article {pmid37642131, year = {2023}, author = {Walasek, L and Brown, GDA}, title = {Incomparability and Incommensurability in Choice: No Common Currency of Value?.}, journal = {Perspectives on psychological science : a journal of the Association for Psychological Science}, volume = {}, number = {}, pages = {17456916231192828}, doi = {10.1177/17456916231192828}, pmid = {37642131}, issn = {1745-6924}, abstract = {Models of decision-making typically assume the existence of some common currency of value, such as utility, happiness, or inclusive fitness. This common currency is taken to allow comparison of options and to underpin everyday choice. Here we suggest instead that there is no universal value scale, that incommensurable values pervade everyday choice, and hence that most existing models of decision-making in both economics and psychology are fundamentally limited. We propose that choice objects can be compared only with reference to specific but nonuniversal "covering values." These covering values may reflect decision-makers' goals, motivations, or current states. A complete model of choice must accommodate the range of possible covering values. We show that abandoning the common-currency assumption in models of judgment and decision-making necessitates rank-based and "simple heuristics" models that contrast radically with conventional utility-based approaches. We note that if there is no universal value scale, then Arrow's impossibility theorem places severe bounds on the rationality of individual decision-making and hence that there is a deep link between the incommensurability of value, inconsistencies in human decision-making, and rank-based coding of value. More generally, incommensurability raises the question of whether it will ever be possible to develop single-quantity-maximizing models of decision-making.}, }
@article {pmid37637319, year = {2023}, author = {Zhang, K and Zhang, ZQ}, title = {A thelytokous predatory mite is more cannibalistic towards distant kin.}, journal = {Current zoology}, volume = {69}, number = {5}, pages = {578-584}, pmid = {37637319}, issn = {1674-5507}, abstract = {Kin recognition has been widely observed in various taxa. Cannibalism avoidance may be a strong driver for the evolution of kin recognition, as it may avoid a reduction in inclusive fitness. Kin recognition has recently been observed in a generalist phytoseiid, Amblyseius herbicolus (Acari: Phytoseiidae). This study experimentally examined the degree of relatedness needed between prey larvae and cannibal adults of A. herbicolus for the occurrence of kin discrimination. The adults were individually placed in enclosed arenas with two prey, a daughter and a more distant related larva, to observe their cannibalizing choice. The adults of A. herbicolus did not discriminate between close relatives (daughter versus niece) but preferably cannibalized more distant kin (i.e., first and second cousins once removed). Phenotype matching and familiarization seem prominent as recognition mechanisms used by A. herbicolus adults. The effect of learning on kin recognition through prior contact in A. herbicolus requires further investigation. Studies on other adaptive functions of kin recognition of A. herbicolus, such as cooperation and parental care, may provide meaningful insights.}, }
@article {pmid37608718, year = {2023}, author = {Úbeda, F and Wild, G}, title = {Microchimerism as a source of information on future pregnancies.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2005}, pages = {20231142}, pmid = {37608718}, issn = {1471-2954}, mesh = {Pregnancy ; Humans ; Female ; *Chimerism ; *Information Sources ; Mothers ; Pelvis ; Placenta ; }, abstract = {Small numbers of fetal cells cross the placenta during pregnancy turning mothers into microchimeras. Fetal cells from all previous pregnancies accumulate forming the mother's fetal microchiome. What is significant about microchimeric cells is that they have been linked to health problems including reproductive and autoimmune diseases. Three decades after the discovery of fetal microchimerism, the function of these cells remains a mystery. Here, we contend that the role of microchimeric cells is to inform the fetus about the likelihood that its genes are present in future pregnancies. We argue that, when genes are more likely than average to be in future maternal siblings, fetuses will send a fixed number of cells that will not elicit a maternal immune response against them. However, when genes are less likely to be in future maternal siblings, fetuses will send an ever-increasing number of cells that will elicit an ever-stronger maternal immune response. Our work can explain the observed clinical association between microchimeric cells and pre-eclampsia. However, our work predicts that this association should be stronger in women with a genetically diverse microchiome. If supported by medical tests, our work would allow establishing the likelihood of pregnancy or autoimmune problems advising medical interventions.}, }
@article {pmid37588900, year = {2022}, author = {He, QQ and Rui, JW and Zhang, L and Tao, Y and Wu, JJ and Mace, R and Ji, T}, title = {Communal breeding by women is associated with lower investment from husbands.}, journal = {Evolutionary human sciences}, volume = {4}, number = {}, pages = {e50}, pmid = {37588900}, issn = {2513-843X}, abstract = {According to Hamilton's rule, matrilineal-biased investment restrains men in matrilineal societies from maximising their inclusive fitness (the 'matrilineal puzzle'). A recent hypothesis argues that when women breed communally and share household resources, a man should help his sisters' household, rather than his wife's household, as investment to the later but not the former would be diluted by other unrelated members (Wu et al., 2013). According to this hypothesis, a man is less likely to help on his wife's farm when there are more women reproducing in the wife's household, because on average he would be less related to his wife's household. We used a farm-work observational dataset, that we collected in the matrilineal Mosuo in southwest China, to test this hypothesis. As predicted, high levels of communal breeding by women in his wife's households do predict less effort spent by men on their wife's farm, and communal breeding in men's natal households do not affect whether men help on their natal farms. Thus, communal breeding by women dilutes the inclusive fitness benefits men receive from investment to their wife and children, and may drive the evolution of matrilineal-biased investment by men. These results can help solve the 'matrilineal puzzle'.}, }
@article {pmid37528574, year = {2023}, author = {Couto, A and Marty, S and Dawson, EH and d'Ettorre, P and Sandoz, JC and Montgomery, SH}, title = {Evolution of the neuronal substrate for kin recognition in social Hymenoptera.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {98}, number = {6}, pages = {2226-2242}, doi = {10.1111/brv.13003}, pmid = {37528574}, issn = {1469-185X}, mesh = {Bees ; Animals ; *Wasps/physiology ; Social Behavior ; *Ants ; Reproduction/physiology ; Selection, Genetic ; Biological Evolution ; Mammals ; }, abstract = {In evolutionary terms, life is about reproduction. Yet, in some species, individuals forgo their own reproduction to support the reproductive efforts of others. Social insect colonies for example, can contain up to a million workers that actively cooperate in tasks such as foraging, brood care and nest defence, but do not produce offspring. In such societies the division of labour is pronounced, and reproduction is restricted to just one or a few individuals, most notably the queen(s). This extreme eusocial organisation exists in only a few mammals, crustaceans and insects, but strikingly, it evolved independently up to nine times in the order Hymenoptera (including ants, bees and wasps). Transitions from a solitary lifestyle to an organised society can occur through natural selection when helpers obtain a fitness benefit from cooperating with kin, owing to the indirect transmission of genes through siblings. However, this process, called kin selection, is vulnerable to parasitism and opportunistic behaviours from unrelated individuals. An ability to distinguish kin from non-kin, and to respond accordingly, could therefore critically facilitate the evolution of eusociality and the maintenance of non-reproductive workers. The question of how the hymenopteran brain has adapted to support this function is therefore a fundamental issue in evolutionary neuroethology. Early neuroanatomical investigations proposed that social Hymenoptera have expanded integrative brain areas due to selection for increased cognitive capabilities in the context of processing social information. Later studies challenged this assumption and instead pointed to an intimate link between higher social organisation and the existence of developed sensory structures involved in recognition and communication. In particular, chemical signalling of social identity, known to be mediated through cuticular hydrocarbons (CHCs), may have evolved hand in hand with a specialised chemosensory system in Hymenoptera. Here, we compile the current knowledge on this recognition system, from emitted identity signals, to the molecular and neuronal basis of chemical detection, with particular emphasis on its evolutionary history. Finally, we ask whether the evolution of social behaviour in Hymenoptera could have driven the expansion of their complex olfactory system, or whether the early origin and conservation of an olfactory subsystem dedicated to social recognition could explain the abundance of eusocial species in this insect order. Answering this question will require further comparative studies to provide a comprehensive view on lineage-specific adaptations in the olfactory pathway of Hymenoptera.}, }
@article {pmid37492150, year = {2023}, author = {Capp, JP and Thomas, F and Marusyk, A and M Dujon, A and Tissot, S and Gatenby, R and Roche, B and Ujvari, B and DeGregori, J and Brown, JS and Nedelcu, AM}, title = {The paradox of cooperation among selfish cancer cells.}, journal = {Evolutionary applications}, volume = {16}, number = {7}, pages = {1239-1256}, pmid = {37492150}, issn = {1752-4571}, support = {U01 CA271830/CA/NCI NIH HHS/United States ; }, abstract = {It is traditionally assumed that during cancer development, tumor cells abort their initially cooperative behavior (i.e., cheat) in favor of evolutionary strategies designed solely to enhance their own fitness (i.e., a "selfish" life style) at the expense of that of the multicellular organism. However, the growth and progress of solid tumors can also involve cooperation among these presumed selfish cells (which, by definition, should be noncooperative) and with stromal cells. The ultimate and proximate reasons behind this paradox are not fully understood. Here, in the light of current theories on the evolution of cooperation, we discuss the possible evolutionary mechanisms that could explain the apparent cooperative behaviors among selfish malignant cells. In addition to the most classical explanations for cooperation in cancer and in general (by-product mutualism, kin selection, direct reciprocity, indirect reciprocity, network reciprocity, group selection), we propose the idea that "greenbeard" effects are relevant to explaining some cooperative behaviors in cancer. Also, we discuss the possibility that malignant cooperative cells express or co-opt cooperative traits normally expressed by healthy cells. We provide examples where considerations of these processes could help understand tumorigenesis and metastasis and argue that this framework provides novel insights into cancer biology and potential strategies for cancer prevention and treatment.}, }
@article {pmid37476514, year = {2023}, author = {Catitti, B and Kormann, UG and van Bergen, VS and Grüebler, MU}, title = {Turning tables: food availability shapes dynamic aggressive behaviour among asynchronously hatching siblings in red kites Milvus milvus.}, journal = {Royal Society open science}, volume = {10}, number = {7}, pages = {230328}, pmid = {37476514}, issn = {2054-5703}, abstract = {Aggression represents the backbone of dominance acquisition in several animal societies, where the decision to interact is dictated by its relative cost. Among siblings, such costs are weighted in the light of inclusive fitness, but how this translates to aggression patterns in response to changing external and internal conditions remains unclear. Using a null-model-based approach, we investigate how day-to-day changes in food provisioning affect aggression networks and food allocation in growing red kite (Milvus milvus) nestlings, whose dominance rank is largely dictated by age. We show that older siblings, irrespective of age, change from targeting only close-aged peers (close-competitor pattern) when food provisioning is low, to uniformly attacking all other peers (downward heuristic pattern) as food conditions improve. While food allocation was generally skewed towards the older siblings, the youngest sibling in the nest increased its probability of accessing food as more was provisioned and as downward heuristic patterns became more prominent, suggesting that different aggression patterns allow for catch-up growth after periods of low food. Our results indicate that dynamic aggression patterns within the nest modulate environmental effects on juvenile development by influencing the process of dominance acquisition and potentially impacting the fledging body condition, with far-reaching fitness consequences.}, }
@article {pmid37459126, year = {2023}, author = {Prigent, I and Mullon, C}, title = {The molding of intraspecific trait variation by selection under ecological inheritance.}, journal = {Evolution; international journal of organic evolution}, volume = {77}, number = {10}, pages = {2144-2161}, doi = {10.1093/evolut/qpad124}, pmid = {37459126}, issn = {1558-5646}, mesh = {Humans ; *Biological Evolution ; *Polymorphism, Genetic ; Models, Theoretical ; Inheritance Patterns ; Phenotype ; }, abstract = {Organisms continuously modify their environment, often impacting the fitness of future conspecifics due to ecological inheritance. When this inheritance is biased toward kin, selection favors modifications that increase the fitness of downstream individuals. How such selection shapes trait variation within populations remains poorly understood. Using mathematical modelling, we investigate the coevolution of multiple traits in a group-structured population when these traits affect the group environment, which is then bequeathed to future generations. We examine when such coevolution favors polymorphism as well as the resulting associations among traits. We find in particular that two traits become associated when one trait affects the environment while the other influences the likelihood that future kin experience this environment. To illustrate this, we model the coevolution of (a) the attack rate on a local renewable resource, which deteriorates environmental conditions, with (b) dispersal between groups, which reduces the likelihood that kin suffers from such deterioration. We show this often leads to the emergence of two highly differentiated morphs: one that readily disperses and depletes local resources, and another that maintains these resources and tends to remain philopatric. More broadly, we suggest that ecological inheritance can contribute to phenotypic diversity and lead to complex polymorphism.}, }
@article {pmid37457894, year = {2023}, author = {Tasaki, E and Mitaka, Y and Takahashi, Y and Waliullah, ASM and Tamannaa, Z and Sakamoto, T and Islam, A and Kamiya, M and Sato, T and Aramaki, S and Kikushima, K and Horikawa, M and Nakamura, K and Kahyo, T and Takata, M and Setou, M and Matsuura, K}, title = {The royal food of termites shows king and queen specificity.}, journal = {PNAS nexus}, volume = {2}, number = {7}, pages = {pgad222}, pmid = {37457894}, issn = {2752-6542}, abstract = {Society in eusocial insects is based on the reproductive division of labor, with a small number of reproductive individuals supported by a large number of nonreproductive individuals. Because inclusive fitness of all colony members depends on the survival and fertility of reproductive members, sterile members provide royals with special treatment. Here, we show that termite kings and queens each receive special food of a different composition from workers. Sequential analysis of feeding processes demonstrated that workers exhibit discriminative trophallaxis, indicating their decision-making capacity in allocating food to the kings and queens. Liquid chromatography tandem-mass spectrometry analyses of the stomodeal food and midgut contents revealed king- and queen-specific compounds, including diacylglycerols and short-chain peptides. Desorption electrospray ionization mass spectrometry imaging analyses of [13]C-labeled termites identified phosphatidylinositol and acetyl-l-carnitine in the royal food. Comparison of the digestive tract structure showed remarkable differences in the volume ratio of the midgut-to-hindgut among castes, indicating that digestive division of labor underlies reproductive division of labor. Our demonstration of king- and queen-specific foods in termites provides insight into the nutritional system that underpins the extraordinary reproduction and longevity of royals in eusocial insects.}, }
@article {pmid37454193, year = {2023}, author = {Green, JP and Franco, C and Davidson, AJ and Lee, V and Stockley, P and Beynon, RJ and Hurst, JL}, title = {Cryptic kin discrimination during communal lactation in mice favours cooperation between relatives.}, journal = {Communications biology}, volume = {6}, number = {1}, pages = {734}, pmid = {37454193}, issn = {2399-3642}, mesh = {Female ; Animals ; Mice ; *Lactation ; *Milk ; Mammals ; }, abstract = {Breeding females can cooperate by rearing their offspring communally, sharing synergistic benefits of offspring care but risking exploitation by partners. In lactating mammals, communal rearing occurs mostly among close relatives. Inclusive fitness theory predicts enhanced cooperation between related partners and greater willingness to compensate for any partner under-investment, while females are less likely to bias investment towards own offspring. We use a dual isotopic tracer approach to track individual milk allocation when familiar pairs of sisters or unrelated house mice reared offspring communally. Closely related pairs show lower energy demand and pups experience better access to non-maternal milk. Lactational investment is more skewed between sister partners but females pay greater energetic costs per own offspring reared with an unrelated partner. The choice of close kin as cooperative partners is strongly favoured by these direct as well as indirect benefits, providing a driver to maintain female kin groups for communal breeding.}, }
@article {pmid37452552, year = {2023}, author = {Achorn, A and Lindshield, S and Ndiaye, PI and Winking, J and Pruetz, JD}, title = {Reciprocity and beyond: Explaining meat transfers in savanna-dwelling chimpanzees at Fongoli, Senegal.}, journal = {American journal of biological anthropology}, volume = {182}, number = {2}, pages = {224-236}, doi = {10.1002/ajpa.24815}, pmid = {37452552}, issn = {2692-7691}, mesh = {Male ; Animals ; *Pan troglodytes ; *Grassland ; Senegal ; Feeding Behavior ; Meat ; }, abstract = {OBJECTIVES: To understand the function of food sharing among our early hominin ancestors, we can turn to our nonhuman primate relatives for insight. Here, we examined the function of meat sharing by Fongoli chimpanzees, a community of western chimpanzees (Pan troglodytes verus) in southeastern Sénégal.<br><br>MATERIALS AND METHODS: We tested three non-mutually exclusive hypotheses that have been used to explain patterns of food sharing: kin selection, generalized reciprocity, and meat-for-mating opportunities. We analyzed meat sharing events (n&#x2009;=&#x2009;484) resulting from hunts, along with data on copulations, age-sex class, and kinship to determine which variables predict the likelihood of meat sharing during this study period (2006-2019).<br><br>RESULTS: We found full or partial support for kin selection, direct reciprocity, and meat-for-mating-opportunities. However, the analyses reveal that reciprocity and a mother/offspring relationship were the strongest predictors of whether or not an individual shared meat.<br><br>CONCLUSIONS: The results of this study emphasize the complexity of chimpanzee meat sharing behaviors, especially at a site where social tolerance offers increased opportunities for meat sharing by individuals other than dominant males. These findings can be placed in a referential model to inform hypotheses about the sensitivity of food sharing to environmental pressures, such as resource scarcity in savanna landscapes.}, }
@article {pmid37434638, year = {2023}, author = {Bose, APH and Dabernig-Heinz, J and Oberkofler, J and Koch, L and Grimm, J and Sefc, KM and Jordan, A}, title = {Aggression and spatial positioning of kin and non-kin fish in social groups.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {34}, number = {4}, pages = {673-681}, pmid = {37434638}, issn = {1045-2249}, support = {P 27605/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Group-living animals are faced with the challenge of sharing space and local resources amongst group members who may be either relatives or non-relatives. Individuals may reduce the inclusive fitness costs they incur from competing with relatives by either reducing their levels of aggression toward kin, or by maintaining physical separation between kin. In this field study, we used the group-living cichlid Neolamprologus multifasciatus to examine whether within-group aggression is reduced among group members that are kin, and whether kin occupy different regions of their group's territory to reduce kin competition over space and local resources. We determined the kinship relationships among cohabiting adults via microsatellite genotyping and then combined these with spatial and behavioral analyses of groups in the wild. We found that aggressive contests between group members declined in frequency with spatial separation between their shelters. Female kin did not engage in aggressive contests with one another, whereas non-kin females did, despite the fact these females lived at similar distances from one another on their groups' territories. Contests within male-male and male-female dyads did not clearly correlate with kinship. Non-kin male-male and male-female dyads lived at more variable distances from one another on their territories than their corresponding kin dyads. Together, our study indicates that contests among group members can be mediated by relatedness in a sex-dependent manner. We also suggest that spatial relationships can play an important role in determining the extent to which group members compete with one another.}, }
@article {pmid37339749, year = {2023}, author = {Micheletti, AJC and Ge, E and Zhou, L and Chen, Y and Du, J and Mace, R}, title = {Correction to: 'Religious celibacy brings inclusive fitness benefits' (2022) by Micheletti et al.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2001}, pages = {20231299}, doi = {10.1098/rspb.2023.1299}, pmid = {37339749}, issn = {1471-2954}, }
@article {pmid37339747, year = {2023}, author = {Micheletti, AJC and Ge, E and Zhou, L and Chen, Y and Du, J and Mace, R}, title = {Studying human culture with small datasets and evolutionary models.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2001}, pages = {20230753}, pmid = {37339747}, issn = {1471-2954}, mesh = {Humans ; *Biological Evolution ; *Selection, Genetic ; Culture ; }, }
@article {pmid37339744, year = {2023}, author = {von Pein, LI and Harper, KT and Zietsch, BP}, title = {No evidence that religious celibacy confers inclusive fitness benefits: a comment on: 'Studying human culture with small datasets and evolutionary models' Micheletti et al. (2022).}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2001}, pages = {20230176}, pmid = {37339744}, issn = {1471-2954}, mesh = {Humans ; *Sexual Abstinence ; *Selection, Genetic ; Biological Evolution ; Genetic Fitness ; Models, Genetic ; }, }
@article {pmid37300791, year = {2023}, author = {Pettay, JE and Danielsbacka, M and Helle, S and Perry, G and Daly, M and Tanskanen, AO}, title = {Parental Investment by Birth Fathers and Stepfathers : Roles of Mating Effort and Childhood Co-residence Duration.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {34}, number = {2}, pages = {276-294}, pmid = {37300791}, issn = {1936-4776}, support = {325857//Academy of Finland/ ; 331400//Academy of Finland/ ; 320162//Academy of Finland/ ; 317808//Academy of Finland/ ; 345183//Strategic Research Council/ ; }, mesh = {Adolescent ; Adult ; Female ; Humans ; Male ; Cross-Sectional Studies ; *Father-Child Relations ; *Fathers/psychology ; Mothers/psychology ; Parenting ; Parents ; Young Adult ; }, abstract = {This study investigates the determinants of paternal investment by birth fathers and stepfathers. Inclusive fitness theory predicts higher parental investment in birth children than stepchildren, and this has consistently been found in previous studies. Here we investigate whether paternal investment varies with childhood co-residence duration and differs between stepfathers and divorced birth fathers by comparing the investment of (1) stepfathers, (2) birth fathers who are separated from the child's mother, and (3) birth fathers who still are in a relationship with her. Path analysis was conducted using cross-sectional data from adolescents and younger adults (aged 17-19, 27-29, and 37-39 years) from the German Family Panel (pairfam), collected in 2010-2011 (n = 8326). As proxies of paternal investment, we used financial and practical help, emotional support, intimacy, and emotional closeness, as reported by the children. We found that birth fathers who were still in a relationship with the mother invested the most, and stepfathers invested the least. Furthermore, the investment of both separated fathers and stepfathers increased with the duration of co-residence with the child. However, in the case of financial help and intimacy, the effect of childhood co-residence duration was stronger in stepfathers than in separated fathers. Our findings support inclusive fitness theory and mating effort theory in explaining social behavior and family dynamics in this population. Furthermore, social environment, such as childhood co-residence was associated with paternal investment.}, }
@article {pmid37285032, year = {2023}, author = {Hu, DZ and Gómez Jiménez, FR and VanderLaan, DP}, title = {A Test of the Kin Selection Hypothesis for Female Gynephilia in Thailand.}, journal = {Archives of sexual behavior}, volume = {52}, number = {5}, pages = {2153-2161}, pmid = {37285032}, issn = {1573-2800}, mesh = {Adult ; Child ; Male ; Humans ; Female ; *Homosexuality, Male ; *Gender Identity ; Thailand ; Sexual Behavior ; Reproduction ; Altruism ; }, abstract = {Female gynephilia (i.e., sexual attraction to adult females) is considered an evolutionary paradox because it reduces direct reproduction, yet it is influenced by genetic factors and has persisted over time and across different cultures. The Kin Selection Hypothesis proposes that same-sex attracted individuals offset their lowered direct reproduction by engaging in kin-directed altruism that increases the reproduction of close genetic relatives, thereby enhancing inclusive fitness. Previous research on male same-sex attraction found evidence to support this hypothesis in some cultures. The present study employed a Thai sample to compare altruistic tendencies towards kin and non-kin children in heterosexual women (n = 285), lesbian women (n = 59), toms (i.e., masculine gynephilic females who take on a nonbinary gender identity; n = 181), and dees (i.e., feminine gynephilic females who are attracted to toms; n = 154). The Kin Selection Hypothesis of same-sex attraction predicts that gynephilic groups would show increased kin-directed altruism compared with heterosexual women, but we did not find evidence supporting this prediction. Instead, the tendency to invest more towards kin than non-kin children was more exaggerated in heterosexual women than lesbian women. Also, heterosexual women showed greater dissociation between kin and non-kin altruistic tendencies compared with toms and dees, which may suggest the former's cognition is better attuned for kin-directed altruism. Thus, the present findings were contrary to the Kin Selection Hypothesis for female gynephilia. Alternative explanations regarding the maintenance of genetic factors predisposing individuals to female gynephilia are discussed and require further investigation.}, }
@article {pmid39296490, year = {2024}, author = {Stucky, K and Gardner, A}, title = {Kin selection favors religious traditions: ancestor worship as a cultural descendant-leaving strategy.}, journal = {Religion, brain &amp; behavior}, volume = {14}, number = {3}, pages = {231-244}, pmid = {39296490}, issn = {2153-599X}, abstract = {Recent years have seen renewed interest in the role of religious systems as drivers of the evolution of cooperation in human societies. One suggestion is that a cultural tradition of ancestor worship might have evolved as a "descendant-leaving strategy" of ancestors by encouraging increased altruism particularly between distant kin. Specifically, Coe and others have suggested a mechanism of cultural transmission exploiting social learning biases, whereby ancestors have been able to establish parental manipulation of kin recognition and perceived relatedness as a traditional behavior, leading to increased altruism among co-descendants and thereby maximizing the ancestor's long-term inclusive fitness. Here, we develop a demographically explicit model in order to quantify the resulting increase in altruism and concomitant "ancestor-descendant conflict", and to determine the evolutionary feasibility of religiously motivated cultural norms that promote altruism among co-descendants. Our analysis reveals that such norms could indeed drive an overall increase in altruism with potential for ancestor-descendant conflict, particularly in low-dispersal settings. Moreover, we find that natural selection can favor traditions encouraging increased altruism towards co-descendants under a range of conditions, with the inclusive-fitness costs of enacting an inappropriately high level of altruism being offset by inclusive-fitness benefits derived from the cultural tradition facilitating kin recognition.}, }
@article {pmid37251589, year = {2023}, author = {Choi, J and Lee, S and Kim, H and Park, J}, title = {The role of recognition error in the stability of green-beard genes.}, journal = {Evolution letters}, volume = {7}, number = {3}, pages = {157-167}, pmid = {37251589}, issn = {2056-3744}, abstract = {The empirical examples of the green-beard genes, once a conundrum of evolutionary biology, are accumulating, while theoretical analyses of this topic are occasional compared to those concerning (narrow-sense) kin selection. In particular, the recognition error of the green-beard effect that the cooperator fails to accurately recognize the other cooperators or defectors is readily found in numerous green-beard genes. To our knowledge, however, no model up to date has taken that effect into account. In this article, we investigated the effect of recognition error on the fitness of the green-beard gene. By employing theories of evolutionary games, our mathematical model predicts that the fitness of the green-beard gene is frequency dependent (frequency of the green-beard gene), which was corroborated by experiments performed with yeast FLO1. The experiment also shows that the cells with the green-beard gene (FLO1) are sturdier under severe stress. We conclude that the low recognition error among the cooperators, the higher reward of cooperation, and the higher cost of defection confer an advantage to the green-beard gene under certain conditions, confirmed by numerical simulation as well. Interestingly, we expect that the recognition error to the defectors may promote the cooperator fitness if the cooperator frequency is low and mutual defection is detrimental. Our ternary approach of mathematical analysis, experiments, and simulation lays the groundwork of the standard model for the green-beard gene that can be generalized to other species.}, }
@article {pmid37198896, year = {2023}, author = {Antfolk, J and Marklund, E and Nylund, I and Gunst, A}, title = {No Signs of Inclusive Fitness or Reciprocal Altruism in Advantageous Inequity Aversion.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {21}, number = {2}, pages = {14747049231173401}, pmid = {37198896}, issn = {1474-7049}, mesh = {Child ; Humans ; Child, Preschool ; *Altruism ; *Social Behavior ; Affect ; Biological Evolution ; Peer Group ; }, abstract = {Advantageous inequity aversion (i.e., the tendency to respond negatively to unfairness that benefits oneself) usually develops in 6-8-year-olds. However, little is known about the selection pressures that might have shaped this phenomenon. Using data collected from 120 4-8-year-old Finnish children, we tested two evolutionary explanations for the development of advantageous inequity aversion: reciprocal altruism (i.e., benefiting from sharing when the roles are likely reversed in the future) and inclusive fitness (i.e., benefiting from sharing with biological relatives that carry the same alleles). We first successfully replicated a previous experiment, showing that 6-8-year-olds display advantageous inequity aversion by preferring to throw away a resource rather than keep it for themselves. Here, this behavior was also displayed in 5-year-olds. Using a novel experiment, we then asked children to distribute five erasers between themselves, a sibling, a peer, and a stranger. That is, an equal distribution was only possible if throwing away one eraser. We found no support for advantageous inequity aversion being shaped by either inclusive fitness or reciprocal altruism. Future studies could investigate costly signaling and adherence to social norms to avoid negative consequences as ultimate explanations for advantageous inequity aversion.}, }
@article {pmid37192926, year = {2023}, author = {Helanterä, H and Ozan, M and Sundström, L}, title = {Relatedness modulates reproductive competition among queens in ant societies with multiple queens.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {34}, number = {3}, pages = {340-345}, pmid = {37192926}, issn = {1045-2249}, abstract = {Reproductive sharing in animal groups with multiple breeders, insects and vertebrates alike, contains elements of both conflict and cooperation, and depends on both relatedness between co-breeders, as well as their internal and external conditions. We studied how queens of the ant Formica fusca adjust their reproductive efforts in response to experimental manipulations of the kin competition regime in their nest. Queens respond to the presence of competitors by increasing their egg laying efforts, but only if the competitors are highly fecund and distantly related. Such a mechanism is likely to decrease harmful competition among close relatives. We demonstrate that queens of Formica fusca fine-tune their cooperative breeding behaviors in response to kinship and fecundity of others in a remarkably precise and flexible manner.}, }
@article {pmid37186853, year = {2023}, author = {Riehl, C and LaPergola, JB}, title = {Inclusive fitness explains behavioral diversity in a social bird.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {21}, pages = {e2305610120}, pmid = {37186853}, issn = {1091-6490}, mesh = {Animals ; *Selection, Genetic ; *Genetic Fitness ; Birds ; Biological Evolution ; Models, Genetic ; }, }
@article {pmid37161292, year = {2023}, author = {Tanskanen, AO and Helle, S and Danielsbacka, M}, title = {Differential grandparental investment when maternal grandmothers are living versus deceased.}, journal = {Biology letters}, volume = {19}, number = {5}, pages = {20230061}, pmid = {37161292}, issn = {1744-957X}, mesh = {Adolescent ; Humans ; *Grandparents ; Uncertainty ; }, abstract = {Grandparents can increase their inclusive fitness by investing time and resources in their grandchildren. However, not all grandparents make such investments equally, and between-grandparent differences in this regard can be predicted based on paternity uncertainty, lineage and grandparents' sex. Using population-based data for English and Welsh adolescents (n = 1430), we examined whether the death of the most important grandparent (in terms of investment), the maternal grandmother (MGM), changes relative support for existing hypotheses predicting differential grandparental-investment patterns. To contrast the predictions of the grandparental investment hypotheses, we used generalized order-restricted information criterion approximation. We consequently found that, when MGMs are alive, the most-supported hypothesis is 'discriminative grandparental solicitude', which ranks grandparental investment as MGMs > maternal grandfathers (MGFs) > paternal grandmothers (PGMs) > paternal grandfathers (PGFs). However, when MGMs are deceased, the paternity uncertainty hypothesis (MGFs = PGMs > PGFs) receives the most support; this is due to increased investment by PGMs. Thus, when the heaviest investors (i.e. MGMs) are deceased, PGM investments are closer to-but do not exceed-MGF investments.}, }
@article {pmid37140644, year = {2023}, author = {Gussone, L and Hüllen, A and Vitt, S and Scherer, U and Thünken, T}, title = {Impact of genetic relatedness on reproductive behavior in Pelvicachromis pulcher, a biparental cichlid fish with mutual mate choice and ornamentation.}, journal = {Die Naturwissenschaften}, volume = {110}, number = {3}, pages = {17}, pmid = {37140644}, issn = {1432-1904}, support = {TH 1615/3-1, TH1615/3-2//Deutsche Forschungsgemeinschaft/ ; SCHU-2927/2-1//Deutsche Forschungsgemeinschaft/ ; }, mesh = {Animals ; Female ; Male ; *Mating Preference, Animal ; *Cichlids/genetics ; Reproduction ; Inbreeding ; Sexual Behavior, Animal ; }, abstract = {Inbreeding can result in inbreeding depression. Therefore, many species seek to avoid inbreeding. However, theory predicts that inbreeding can be beneficial. Accordingly, some species tolerate inbreeding or even prefer mating with close relatives. Evidence for active inbreeding, i.e., kin-mating preference was reported in the biparental African cichlid fish Pelvicachromis taeniatus. Related mating partners revealed better parental cooperation due to kin selection, a potential benefit of inbreeding. In this study, we investigated kin-mating preference in a genetically diverse, outbred F2-lab population of Pelvicachromis pulcher, a closely related species to P. taeniatus. Like P. taeniatus, this species shows mutual ornamentation and mate choice as well as intense biparental brood care. The F1 P. pulcher generation had revealed signs of inbreeding depression but no inbreeding avoidance. We studied mating behavior and aggression in trios consisting of a male P. pulcher, an unfamiliar sister, and an unfamiliar, unrelated female. Because the study focused on kin-mating patterns, female pairs were matched for body size and coloration. The results provide no evidence for inbreeding avoidance but rather suggest inbreeding preference. We also found no significant impact of inbreeding on offspring survival. The results suggest no inbreeding avoidance in P. pulcher; however, the strength of inbreeding preference and inbreeding depression seems to be variable. We discuss possible causes for this variation like context-dependent inbreeding depression. The number of eggs positively correlated with female body size and coloration. Furthermore, the female aggressiveness was positively correlated with female coloration indicating that coloration signal female dominance and quality.}, }
@article {pmid37126712, year = {2023}, author = {Koenig, WD and Barve, S and Haydock, J and Dugdale, HL and Oli, MK and Walters, EL}, title = {Lifetime inclusive fitness effects of cooperative polygamy in the acorn woodpecker.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {19}, pages = {e2219345120}, pmid = {37126712}, issn = {1091-6490}, mesh = {Animals ; Female ; Male ; *Marriage ; *Birds ; Social Behavior ; Reproduction ; Altruism ; Cooperative Behavior ; }, abstract = {Although over 50 y have passed since W. D. Hamilton articulated kin selection and inclusive fitness as evolutionary explanations for altruistic behavior, quantifying inclusive fitness continues to be challenging. Here, using 30 y of data and two alternative methods, we outline an approach to measure lifetime inclusive fitness effects of cooperative polygamy (mate-sharing or cobreeding) in the cooperatively breeding acorn woodpecker Melanerpes formicivorus. For both sexes, the number of offspring (observed direct fitness) declined while the number of young parented by related cobreeders (observed indirect fitness effect) increased with cobreeding coalition size. Combining these two factors, the observed inclusive fitness effect of cobreeding was greater than breeding singly for males, while the pattern for females depended on whether fitness was age-weighted, as females breeding singly accrued greater fitness at younger ages than cobreeding females. Accounting for the fitness birds would have obtained by breeding singly, however, lifetime inclusive fitness effects declined with coalition size for males, but were greater for females breeding as duos compared to breeding singly, due largely to indirect fitness effects of kin. Our analyses provide a road map for, and demonstrate the importance of, quantifying indirect fitness as a powerful evolutionary force contributing to the costs and benefits of social behaviors.}, }
@article {pmid37094171, year = {2023}, author = {Shah, SS and Rubenstein, DR}, title = {Group augmentation underlies the evolution of complex sociality in the face of environmental instability.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {18}, pages = {e2212211120}, pmid = {37094171}, issn = {1091-6490}, mesh = {Humans ; Male ; Female ; Animals ; *Social Behavior ; *Birds ; Breeding ; Sex ; Reproduction ; Cooperative Behavior ; }, abstract = {Although kin selection is assumed to underlie the evolution of sociality, many vertebrates-including nearly half of all cooperatively breeding birds-form groups that also include unrelated individuals. Theory predicts that despite reducing kin structure, immigration of unrelated individuals into groups can provide direct, group augmentation benefits, particularly when offspring recruitment is insufficient for group persistence. Using population dynamic modeling and analysis of long-term data, we provide clear empirical evidence of group augmentation benefits favoring the evolution and maintenance of complex societies with low kin structure and multiple reproductives. We show that in the superb starling (Lamprotornis superbus)-a plural cooperative breeder that forms large groups with multiple breeding pairs, and related and unrelated nonbreeders of both sexes-offspring recruitment alone cannot prevent group extinction, especially in smaller groups. Further, smaller groups, which stand to benefit more from immigration, exhibit lower reproductive skew for immigrants, suggesting that reproductive opportunities as joining incentives lead to plural breeding. Yet, despite a greater likelihood of becoming a breeder in smaller groups, immigrants are more likely to join larger groups where they experience increased survivorship and greater reproductive success as breeders. Moreover, immigrants form additional breeding pairs, increasing future offspring recruitment into the group and guarding against complete reproductive failure in the face of environmental instability and high nest predation. Thus, plural breeding likely evolves because the benefits of group augmentation by immigrants generate a positive feedback loop that maintains societies with low and mixed kinship, large group sizes, and multiple reproductives.}, }
@article {pmid37092004, year = {2023}, author = {Guo, Y and Grueter, CC and Lu, J}, title = {Allomaternal care and 'adoption' in an edge-of-range population of Taihangshan macaques in Northern China.}, journal = {Current zoology}, volume = {69}, number = {2}, pages = {215-218}, pmid = {37092004}, issn = {1674-5507}, }
@article {pmid37075326, year = {2023}, author = {van Dokkum, NH and Fagan, LJ and Cullen, M and Loewy, JV}, title = {Assessing HeartSong as a Neonatal Music Therapy Intervention: A Qualitative Study on Personal and Professional Caregivers' Perspectives.}, journal = {Advances in neonatal care : official journal of the National Association of Neonatal Nurses}, volume = {23}, number = {3}, pages = {264-271}, doi = {10.1097/ANC.0000000000001068}, pmid = {37075326}, issn = {1536-0911}, mesh = {*Music Therapy ; *Caregivers ; Humans ; Object Attachment ; Qualitative Research ; Intensive Care, Neonatal ; Heart Rate ; *Parents ; Family Support ; Male ; Female ; Infant, Newborn ; Adult ; Bereavement ; }, abstract = {BACKGROUND: The music therapy HeartSong intervention pairs newborn infant heartbeats with parents' Song of Kin. Formal evidence on professional and personal caregiver perspectives of this intervention is lacking.<br><br>PURPOSE: This survey study evaluates the HeartSong music therapy intervention from parent and staff perspectives.<br><br>METHODS: A qualitative study assessing inclusion of HeartSong for family neonatal intensive care unit (NICU) care surveyed 10 professional caregivers comprising medical and psychosocial NICU teams anonymously reflecting their impressions of the intervention. Digital survey of parents/guardians contacted through semistructured phone interviews relayed impressions of recordings: subsequent setup, Song of Kin selection, and use of HeartSong, including thoughts/feelings about it as an intervention.<br><br>RESULTS: Professional and personal caregivers valued the HeartSong intervention for bereavement support, family support, including parental, extended family/infant support, and to enhance bonding. Emergent themes: memory-making, connectedness/closeness, support of parent role, processing mental health needs of stressful NICU days, and subsequent plans for lifelong HeartSong use. Therapeutic experience was named as a crucial intervention aspect and participants recommended the HeartSong as a viable, accessible NICU intervention.<br><br>HeartSong's use showed efficacy as a clinical NICU music therapy intervention for families of critically ill and extremely preterm infants, when provided by trained, specialized, board-certified music therapists. Future research focusing on HeartSong in other NICU populations might benefit infants with cardiac disease, parental stress, and anxiety attending to parent-infant bonding. Costs and time benefits related to investment are needed before implementation is considered.}, }
@article {pmid37072037, year = {2023}, author = {Fuirst, M and Strickland, D and Freeman, NE and Sutton, AO and Ryan Norris, D}, title = {Early-life sibling conflict in Canada jays has lifetime fitness consequences.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {1997}, pages = {20221863}, pmid = {37072037}, issn = {1471-2954}, mesh = {Animals ; Humans ; *Siblings ; *Songbirds ; Reproduction ; Ontario ; Birth Order ; Genetic Fitness ; }, abstract = {While delaying natal dispersal can provide short-term benefits for juveniles, lifetime fitness consequences are rarely assessed. Furthermore, competition for limited positions on a natal territory could impose an indirect fitness cost on the winner if the outcome has negative effects on its siblings. We use radio-tracking and 58 years of nesting data in Ontario, Canada to examine the lifetime fitness consequences of sibling expulsion in the Canada jay (Perisoreus canadensis). Six weeks after fledging, intra-brood dominance struggles result in one 'dominant juvenile' (DJ) remaining on the natal territory after expelling its subordinate siblings, the 'ejectees' (EJs). Despite an older age-at-first-reproduction, DJs produced more recruits over their lifetime and had higher first-year survival than EJs, leading to substantially higher direct fitness. Even though DJs incurred an indirect fitness cost by expelling their siblings and there was no evidence that their presence on the natal territory increased their parents' reproductive output the following year, they still had substantially higher inclusive fitness than EJs. Our results demonstrate how early-life sibling conflict can have lifetime consequences and that such fitness differences in Canada jays are driven by the enhanced first-year survival of DJs pursuant to the early-summer expulsion of their sibling competitors.}, }
@article {pmid37065817, year = {2023}, author = {Knorr, DA and Fox, M}, title = {An evolutionary perspective on the association between grandmother-mother relationships and maternal mental health among a cohort of pregnant Latina women.}, journal = {Evolution and human behavior : official journal of the Human Behavior and Evolution Society}, volume = {44}, number = {1}, pages = {30-38}, pmid = {37065817}, issn = {1090-5138}, support = {K01 DK105110/DK/NIDDK NIH HHS/United States ; P2C HD041022/HD/NICHD NIH HHS/United States ; R03 DK125524/DK/NIDDK NIH HHS/United States ; }, abstract = {Grandmothers are often critical helpers during a mother's reproductive career. Studies on the developmental origins of health and disease demonstrate how maternal psychological distress can negatively influence fetal development and birth outcomes, highlighting an area in which soon-to-be grandmothers (henceforth "grandmothers") can invest to improve both mother and offspring well-being. Here, we examine if and how a pregnant woman's mental health- specifically, depression, state-anxiety, and pregnancy-related anxiety- is influenced by her relationship with her fetus' maternal and paternal grandmother, controlling for relationship characteristics with her fetus' father. In a cohort of pregnant Latina women in Southern California (N = 216), we assessed social support, geographic proximity, and communication between the fetus' grandmothers and pregnant mother. We assessed maternal mental health with validated questionnaire-based instruments. We find that both social support from and communication with the maternal grandmother were statistically associated with less depression, while no paternal grandmother relationship characteristics were statistically significant in association with any mental health variable. These results align with the idea that maternal grandmothers are more adaptively incentivized to invest in their daughters' well-being during pregnancy than paternal grandmothers are for their daughters-in-law. Results suggest that the positive association of maternal grandmothers with mothers' mental health may not hinge on geographic proximity, but rather, potentially function through emotional support. This work represents a novel perspective describing a psychological and prenatal grandmaternal effect.}, }
@article {pmid37046187, year = {2023}, author = {Jones, CT and Meynell, L and Neto, C and Susko, E and Bielawski, JP}, title = {The role of the ecological scaffold in the origin and maintenance of whole-group trait altruism in microbial populations.}, journal = {BMC ecology and evolution}, volume = {23}, number = {1}, pages = {11}, pmid = {37046187}, issn = {2730-7182}, mesh = {*Biological Evolution ; *Altruism ; Models, Theoretical ; Computer Simulation ; Cooperative Behavior ; }, abstract = {BACKGROUND: Kin and multilevel selection provide explanations for the existence of altruism based on traits or processes that enhance the inclusive fitness of an altruist individual. Kin selection is often based on individual-level traits, such as the ability to recognize other altruists, whereas multilevel selection requires a metapopulation structure and dispersal process. These theories are unified by the general principle that altruism can be fixed by positive selection provided the benefit of altruism is preferentially conferred to other altruists. Here we take a different explanatory approach based on the recently proposed concept of an "ecological scaffold". We demonstrate that ecological conditions consisting of a patchy nutrient supply that generates a metapopulation structure, episodic mixing of groups, and severe nutrient limitation, can support or "scaffold" the evolution of altruism in a population of microbes by amplifying drift. This contrasts with recent papers in which the ecological scaffold was shown to support selective processes and demonstrates the power of scaffolding even in the absence of selection.<br><br>RESULTS: Using computer simulations motivated by a simple theoretical model, we show that, although an altruistic mutant can be fixed within a single population of non-altruists by drift when nutrients are severely limited, the resulting altruistic population remains vulnerable to non-altruistic mutants. We then show how the imposition of the "ecological scaffold" onto a population of non-altruists alters the balance between selection and drift in a way that supports the fixation and subsequent persistence of altruism despite the possibility of invasion by non-altruists.<br><br>CONCLUSIONS: The fixation of an altruistic mutant by drift is possible when supported by ecological conditions that impose a metapopulation structure, episodic mixing of groups, and severe nutrient limitation. This is significant because it offers an alternative explanation for the evolution of altruism based on drift rather than selection. Given the ubiquity of low-nutrient "oligotrophic" environments in which microbes exist (e.g., the open ocean, deep subsurface soils, or under the polar ice caps) our results suggest that altruistic and cooperative behaviors may be highly prevalent among microbial populations.}, }
@article {pmid37027070, year = {2023}, author = {Nautiyal, H and Tanaka, H and Huffman, MA}, title = {Anti-predator strategies of adult male Central Himalayan Langurs (Semnopithecus schistaceus) in response to domestic dogs in a human-dominated landscape.}, journal = {Primates; journal of primatology}, volume = {64}, number = {3}, pages = {361-379}, pmid = {37027070}, issn = {1610-7365}, mesh = {Humans ; Animals ; Male ; Dogs ; Female ; *Presbytini ; Reproduction ; Primates ; Predatory Behavior ; India ; }, abstract = {The evolution of predator-prey relationships is an important topic in primatology. Many aspects of primate society have been explained as a response to predation pressure. While predation has been discussed in broad theoretical terms, few systematically collected data exist on the subject. Furthermore, little information exists regarding the inter-male variation in responses to predators. To address this data gap, predatory dog-primate interactions were studied in a 78-member group of habituated, individually recognized Central Himalayan Langurs (CHL) (Semnopithecus schistaceus) living in a high-altitude subsistence agricultural landscape of northern India. We recorded 312 langur-dog interactions over 2 years. These predation events resulted in 15 serious attacks on adult females, infants, juveniles and sub-adults, in eight of which the prey was killed and consumed on the spot. In response to dog predation, adult males performed three types of anti-predator response behaviors: direct fighting with a predator, emitting alarm calls, fleeing and/or freezing. Differences were noted in each male's response to village dogs. The results showed that the likelihood of CHL adult males engaging in more costly counterattacks or attention getting alarm calls were better predicted by the level of investment in the group (genetic relatedness, duration of residency, social relationships), but not rank and mating rate. Long-duration resident adult males performed high and/or intermediate cost behaviors to protect vulnerable members of the group; their potential offspring, maternal siblings or cousins, and adult female social partners. Short-term residents or recent immigrant males exhibited two less energetically costly, more self-preserving behaviors, depending on their rank: (1) high-ranking short-tenure duration males, with high mating frequencies, performed flee and freeze responses; (2) low-ranking, low-mating-frequency males performed more alarm calls. Counterattacks and alarm calls were performed by adult males with relatively more experience with village dogs and were directed towards dogs with predatory histories significantly more often than dogs with non-predatory histories. Natural selection and kin selection have both contributed to the evolution of CHL anti-predator tactics.}, }
@article {pmid36974150, year = {2023}, author = {Li, Z and Da, X and Lu, X}, title = {Complementary interactions between indirect and direct fitness in a cooperatively breeding bird.}, journal = {Current zoology}, volume = {69}, number = {1}, pages = {76-81}, pmid = {36974150}, issn = {1674-5507}, abstract = {Altruism is difficult to explain evolutionarily and to understand it, there is a need to quantify the benefits and costs to altruists. Hamilton's theory of kin selection argues that altruism can persist if the costs to altruists are offset by indirect fitness payoffs from helping related recipients. Nevertheless, helping nonkin is also common and in such situations, the costs must be compensated for by direct benefits. While previous researchers tended to evaluate the indirect and direct fitness in isolation, we expect that they have a complementary interaction where altruists are associated with recipients of different relatedness within a population. The prediction is tested with 12 years of data on lifetime reproductive success for a cooperatively breeding bird, Tibetan ground tits Pseudopodoces humilis. Helpers who helped distantly related recipients gained significantly lower indirect benefits than those who helped closely related recipients, but the opposite was true for direct fitness, thereby making these helpers have an equal inclusive fitness. Helping efforts were independent of helpers' relatedness to recipients, but those helping distantly related recipients were more likely to inherit the resident territory, which could be responsible for their high direct reproductive success. Our findings provide an explanatory model for the widespread coexistence of altruists and recipients with varying relatedness within a single population.}, }
@article {pmid36972783, year = {2023}, author = {Wild, G and Flear, VJ and Thompson, GJ}, title = {A kin-selection model of fairness in heterogeneous populations.}, journal = {Journal of theoretical biology}, volume = {565}, number = {}, pages = {111469}, doi = {10.1016/j.jtbi.2023.111469}, pmid = {36972783}, issn = {1095-8541}, mesh = {Animals ; Humans ; *Altruism ; *Motivation ; Biological Evolution ; }, abstract = {Humans and other primates exhibit pro-social preferences for fairness. These preferences are thought to be reinforced by strong reciprocity, a policy that rewards fair actors and punishes unfair ones. Theories of fairness based on strong reciprocity have been criticized for overlooking the importance of individual differences in socially heterogeneous populations. Here, we explore the evolution of fairness in a heterogeneous population. We analyse the Ultimatum Game in cases where players' roles in the game are determined by their status. Importantly, our model allows for non-random pairing of players, and so we also explore the role played by kin selection in shaping fairness. Our kin-selection model shows that, when individuals condition their behaviour on their role in the game, fairness can be understood as either altruistic or spiteful. Altruistic fairness directs resources from less valuable members of a genetic lineage to more valuable members of the same lineage, whereas spiteful fairness keeps resources away from the competitors of the actor's high-value relatives. When individuals express fairness unconditionally it can be understood as altruistic or selfish. When it is altruistic, unconditional fairness again serves to direct resources to high-value members of genetic lineages. When it is selfish, unconditional fairness simply improves an individual's own standing. Overall, we expand kin-selection based explanations for fairness to include motivations other than spite. We show, therefore, that one need not invoke strong reciprocity to explain the advantage of fairness in heterogeneous populations.}, }
@article {pmid36934761, year = {2023}, author = {Lehtonen, J and Otsuka, J}, title = {Evolutionary game theory of continuous traits from a causal perspective.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {378}, number = {1876}, pages = {20210507}, pmid = {36934761}, issn = {1471-2970}, mesh = {Humans ; *Game Theory ; Biological Evolution ; Models, Theoretical ; *Frailty ; Phenotype ; }, abstract = {Modern evolutionary game theory typically deals with the evolution of continuous, quantitative traits under weak selection, allowing the incorporation of rich biological detail and complicated nonlinear interactions. While these models are commonly used to find candidates for evolutionary endpoints and to approximate evolutionary trajectories, a less appreciated property is their potential to expose and clarify the causal structure of evolutionary processes. The mathematical step of differentiation breaks a nonlinear model into additive components which are more intuitive to interpret, and when combined with a proper causal hypothesis, partial derivatives in such models have a causal meaning. Such an approach has been used in the causal analysis of game-theoretical models in an informal manner. Here we formalize this approach by linking evolutionary game theory to concepts developed in causal modelling over the past century, from path coefficients to the recently proposed causal derivative. There is a direct correspondence between the causal derivative and the derivative used in evolutionary game theory. Some game theoretical models (e.g. kin selection) consist of multiple causal derivatives. Components of these derivatives correspond to components of the causal derivative, to path coefficients, and to edges on a causal graph, formally linking evolutionary game theory to causal modelling. This article is part of the theme issue 'Half a century of evolutionary games: a synthesis of theory, application and future directions'.}, }
@article {pmid36934754, year = {2023}, author = {Van Cleve, J}, title = {Evolutionarily stable strategy analysis and its links to demography and genetics through invasion fitness.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {378}, number = {1876}, pages = {20210496}, pmid = {36934754}, issn = {1471-2970}, mesh = {Humans ; *Biological Evolution ; Phenotype ; Uncertainty ; Demography ; *Game Theory ; Models, Genetic ; Selection, Genetic ; }, abstract = {Evolutionarily stable strategy (ESS) analysis pioneered by Maynard Smith and Price took off in part because it often does not require explicit assumptions about the genetics and demography of a population in contrast to population genetic models. Though this simplicity is useful, it obscures the degree to which ESS analysis applies to populations with more realistic genetics and demography: for example, how does ESS analysis handle complexities such as kin selection, group selection and variable environments when phenotypes are affected by multiple genes? In this paper, I review the history of the ESS concept and show how early uncertainty about the method lead to important mathematical theory linking ESS analysis to general population genetic models. I use this theory to emphasize the link between ESS analysis and the concept of invasion fitness. I give examples of how invasion fitness can measure kin selection, group selection and the evolution of linked modifier genes in response to variable environments. The ESSs in these examples depend crucially on demographic and genetic parameters, which highlights how ESS analysis will continue to be an important tool in understanding evolutionary patterns as new models address the increasing abundance of genetic and long-term demographic data in natural populations. This article is part of the theme issue 'Half a century of evolutionary games: a synthesis of theory, application and future directions'.}, }
@article {pmid36916702, year = {2023}, author = {Mazal, L and Fajardo, A and Till-Bottraud, I and Corenblit, D and Fumanal, B}, title = {Kin selection, kin recognition and kin discrimination in plants revisited: A claim for considering environmental and genetic variability.}, journal = {Plant, cell &amp; environment}, volume = {46}, number = {7}, pages = {2007-2016}, doi = {10.1111/pce.14584}, pmid = {36916702}, issn = {1365-3040}, mesh = {*Biological Evolution ; Phenotype ; }, }
@article {pmid36862026, year = {2023}, author = {Fox, MM and Knorr, DA and Kwon, D and Wiley, KS and Parrish, MH}, title = {How prenatal cortisol levels relate to grandmother-mother relationships among a cohort of Latina women.}, journal = {American journal of human biology : the official journal of the Human Biology Council}, volume = {35}, number = {7}, pages = {e23883}, pmid = {36862026}, issn = {1520-6300}, support = {F32 MD015201/MD/NIMHD NIH HHS/United States ; K01 DK105110/DK/NIDDK NIH HHS/United States ; R03 DK125524/DK/NIDDK NIH HHS/United States ; }, mesh = {Female ; Humans ; Pregnancy ; *Mothers/psychology ; *Grandparents ; Hydrocortisone ; Nuclear Family ; Vitamins ; }, abstract = {INTRODUCTION: As part of the human reproductive strategy, mothers receive childcare assistance from others. For kin, allomothers are adaptively incentivized to provide assistance due to inclusive fitness benefits. Previous studies across a broad range of populations identify grandmothers as particularly consistent allomothers. Minimal attention has been paid to the possibility that allomothers may begin investing in offspring quality during the prenatal stage of life. Here, we innovate within the area of grandmother allocare research by examining the prenatal stage of life and biopsychosocial mechanisms by which prenatal grandmother effects may be enacted.<br><br>METHODS: Data derive from the Mothers' Cultural Experiences study, a cohort of 107 pregnant Latina women in Southern California. At <16&#x2009;weeks' gestation, we administered questionnaires, collected morning urine samples, and measured cortisol by enzyme-linked immunosorbent assay, correcting for specific gravity. We measured the soon-to-be maternal and paternal grandmothers' relationship quality, social support, frequency of seeing each other, communicating, and geographic proximity to pregnant mothers, that is, their daughters and daughters-in-law. These measures were self-reported by the pregnant mothers. We assessed how grandmother constructs related to the pregnant women's depression, stress, anxiety, and cortisol levels.<br><br>RESULTS: We observed benefits conferred by maternal grandmothers for mothers' prenatal mental health and lower cortisol levels. Paternal grandmothers also conferred mental health benefits to pregnant daughters-in-law, but higher cortisol levels.<br><br>CONCLUSION: Our results suggest that grandmothers, especially maternal grandmothers, are able to improve their inclusive fitness by caring for pregnant daughters, and allomother support may positively impact prenatal health. This work extends the traditional cooperative breeding model by identifying a prenatal grandmother effect, and, by examining a maternal biomarker.}, }
@article {pmid36802776, year = {2023}, author = {Rodrigues, AMM and Barker, JL and Robinson, EJH}, title = {The evolution of intergroup cooperation.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {378}, number = {1874}, pages = {20220074}, pmid = {36802776}, issn = {1471-2970}, mesh = {Animals ; *Biological Evolution ; *Social Behavior ; Aggression ; Altruism ; Primates ; Cooperative Behavior ; }, abstract = {Sociality is widespread among animals, and involves complex relationships within and between social groups. While intragroup interactions are often cooperative, intergroup interactions typically involve conflict, or at best tolerance. Active cooperation between members of distinct, separate groups occurs very rarely, predominantly in some primate and ant species. Here, we ask why intergroup cooperation is so rare, and what conditions favour its evolution. We present a model incorporating intra- and intergroup relationships and local and long-distance dispersal. We show that dispersal modes play a pivotal role in the evolution of intergroup interactions. Both long-distance and local dispersal processes drive population social structure, and the costs and benefits of intergroup conflict, tolerance and cooperation. Overall, the evolution of multi-group interaction patterns, including both intergroup aggression and intergroup tolerance, or even altruism, is more likely with mostly localized dispersal. However, the evolution of these intergroup relationships may have significant ecological impacts, and this feedback may alter the ecological conditions that favour its own evolution. These results show that the evolution of intergroup cooperation is favoured by a specific set of conditions, and may not be evolutionarily stable. We discuss how our results relate to empirical evidence of intergroup cooperation in ants and primates. This article is part of a discussion meeting issue 'Collective behaviour through time'.}, }
@article {pmid36792870, year = {2023}, author = {Santoriello, F and Pukatzki, S}, title = {Type VI Secretion Systems: Environmental and Intra-host Competition of Vibrio cholerae.}, journal = {Advances in experimental medicine and biology}, volume = {1404}, number = {}, pages = {41-63}, pmid = {36792870}, issn = {0065-2598}, mesh = {*Type VI Secretion Systems/genetics/metabolism ; *Vibrio cholerae/genetics/metabolism ; Bacterial Proteins/genetics/metabolism ; Virulence/genetics ; }, abstract = {The Vibrio Type VI Secretion System (T6SS) is a harpoon-like nanomachine that serves as a defense system and is encoded by approximately 25% of all gram-negative bacteria. In this chapter, we describe the structure of the T6SS in different Vibrio species and outline how the use of different T6SS effector and immunity proteins control kin selection. We summarize the genetic loci that encode the structural elements that make up the Vibrio T6SSs and how these gene clusters are regulated. Finally, we provide insights into T6SS-based competitive dynamics, the role of T6SS genetic exchange in those competitive dynamics, and roles for the Vibrio T6SS in virulence.}, }
@article {pmid36724459, year = {2023}, author = {Fischer, S and Duffield, C and Davidson, AJ and Bolton, R and Hurst, JL and Stockley, P}, title = {Fitness Costs of Female Competition Linked to Resource Defense and Relatedness of Competitors.}, journal = {The American naturalist}, volume = {201}, number = {2}, pages = {256-268}, doi = {10.1086/722513}, pmid = {36724459}, issn = {1537-5323}, mesh = {Animals ; Mice ; Female ; Humans ; *Social Behavior ; *Cooperative Behavior ; Social Environment ; Siblings ; Reproduction ; }, abstract = {AbstractFemale reproductive success is often limited by access to resources, and this can lead to social competition both within and between kin groups. Theory predicts that both resource availability and relatedness should influence the fitness consequences of social competition. However, testing key predictions requires differentiating the effects of these two factors. Here, we achieve this experimentally by manipulating the social environment of house mice, a facultative communal breeding species with known kin discrimination ability. This allows us to investigate (1) the reproductive costs of defending a limited resource in response to cues of social competition and (2) whether such costs, or their potential mitigation via cooperative behavior, are influenced by the relatedness of competitors. Our results support the hypothesis that resource defense can be costly for females, potentially trading off against maternal investment. When the availability of protected nest sites was limited, subjects (1) were more active, (2) responded more strongly to simulated territory intrusions via competitive signaling, and (3) produced smaller weaned offspring. However, we found no evidence that the propensity for kin to cooperate was influenced by the relatedness of rivals. Communal breeding between sisters occurred independently of the relatedness of competitors and communally breeding sisters weaned fewer offspring when competing with unrelated females, despite our study being designed to prevent infanticide between kin groups. Our findings thus demonstrate that female competition has fitness costs and that associating with kin is beneficial to avoid negative fitness consequences of competing with nonkin, in addition to more widely recognized kin-selected benefits.}, }
@article {pmid36717460, year = {2022}, author = {Leake, DW}, title = {Tracing Slow Phenoptosis to the Prenatal Stage in Social Vertebrates.}, journal = {Biochemistry. Biokhimiia}, volume = {87}, number = {12}, pages = {1512-1527}, doi = {10.1134/S0006297922120094}, pmid = {36717460}, issn = {1608-3040}, mesh = {Animals ; Humans ; Aged ; *Aging/genetics ; *Vertebrates ; }, abstract = {Vladimir Skulachev's coining of the term "phenoptosis" 25 years ago (Skulachev, V. P., Biochemistry (Moscow), 62, 1997) highlighted the theoretical possibility that aging is a programmed process to speed the exit of individuals posing some danger to their social group. While rapid "acute phenoptosis" might occur at any age (e.g., to prevent spread of deadly infections), "slow phenoptosis" is generally considered to occur later in life in the form of chronic age-related disorders. However, recent research indicates that risks for such chronic disorders can be greatly raised by early life adversity, especially during the prenatal stage. Much of this research uses indicators of biological aging, the speeding or slowing of natural physiological deterioration in response to environmental inputs, leading to divergence from chronological age. Studies using biological aging indicators commonly find it is accelerated not only in older individuals with chronic disorders, but also in very young individuals with health problems. This review will explain how accelerated biological aging equates to slow phenoptosis. Its occurrence even in the prenatal stage is theoretically supported by W. D. Hamilton's proposal that offsprings detecting they have dangerous mutations should then automatically speed their demise, in order to improve their inclusive fitness by giving their parents the chance to produce other fitter siblings.}, }
@article {pmid36717459, year = {2022}, author = {Pandey, T and Ma, DK}, title = {Stress-Induced Phenoptosis: Mechanistic Insights and Evolutionary Implications.}, journal = {Biochemistry. Biokhimiia}, volume = {87}, number = {12}, pages = {1504-1511}, doi = {10.1134/S0006297922120082}, pmid = {36717459}, issn = {1608-3040}, mesh = {Animals ; Humans ; *Caenorhabditis elegans/genetics ; *Apoptosis ; Aging/genetics ; Bacteria ; Signal Transduction ; Biological Evolution ; Mammals ; }, abstract = {Evolution by natural selection results in biological traits that enable organismic adaptation and survival under various stressful environments. External stresses can be sometimes too severe to overcome, leading to organismic death either because of failure in adapting to such stress, or alternatively, through a regulated form of organismic death (phenoptosis). While regulated cell deaths, including apoptosis, have been extensively studied, little is known about the molecular and cellular mechanisms underlying phenoptosis and its evolutionary significance for multicellular organisms. In this article, we review documented phenomena and mechanistic evidence emerging from studies of stress-induced phenoptosis in the multicellular organism C. elegans and stress-induced deaths at cellular levels in organisms ranging from bacteria to mammals, focusing on abiotic and pathogen stresses. Genes and signaling pathways involved in phenoptosis appear to promote organismic death during severe stress and aging, while conferring fitness and immune defense during mild stress and early life, consistent with their antagonistic pleiotropy actions. As cell apoptosis during development can shape tissues and organs, stress-induced phenoptosis may also contribute to possible benefits at the population level, through mechanisms including kin selection, abortive infection, and soma-to-germline resource allocation. Current models can generate experimentally testable predictions and conceptual frameworks with implications for understanding both stress-induced phenoptosis and natural aging.}, }
@article {pmid36717438, year = {2022}, author = {Lidsky, PV and Yuan, J and Rulison, JM and Andino-Pavlovsky, R}, title = {Is Aging an Inevitable Characteristic of Organic Life or an Evolutionary Adaptation?.}, journal = {Biochemistry. Biokhimiia}, volume = {87}, number = {12}, pages = {1413-1445}, pmid = {36717438}, issn = {1608-3040}, mesh = {Humans ; Aged ; *Biological Evolution ; *Aging ; Longevity ; Adaptation, Physiological ; }, abstract = {Aging is an evolutionary paradox. Several hypotheses have been proposed to explain it, but none fully explains all the biochemical and ecologic data accumulated over decades of research. We suggest that senescence is a primitive immune strategy which acts to protect an individual's kin from chronic infections. Older organisms are exposed to pathogens for a longer period of time and have a higher likelihood of acquiring infectious diseases. Accordingly, the parasitic load in aged individuals is higher than in younger ones. Given that the probability of pathogen transmission is higher within the kin, the inclusive fitness cost of infection might exceed the benefit of living longer. In this case, programmed lifespan termination might be an evolutionarily stable strategy. Here, we discuss the classical evolutionary hypotheses of aging and compare them with the pathogen control hypothesis, discuss the consistency of these hypotheses with existing empirical data, and present a revised conceptual framework to understand the evolution of aging.}, }
@article {pmid36652244, year = {2023}, author = {Wild, G}, title = {Technical comment on "sex ratios when helpers stay at the nest".}, journal = {Evolution; international journal of organic evolution}, volume = {77}, number = {3}, pages = {921-927}, doi = {10.1093/evolut/qpad007}, pmid = {36652244}, issn = {1558-5646}, mesh = {Female ; Male ; *Sex Ratio ; Animals ; }, abstract = {I contributed a paper to volume 60 of the journal. The paper reported on my study of sex-ratio evolution when one sex (females) is helpful but the other sex (males) suffers less from kin competition. I had based my study on a kin-selection model, and so I was dismayed to discover an error in the relatedness calculations therein. Specifically, relatedness coefficients that should have been calculated using a sampling-without-replacement scheme were instead calculated using sampling with replacement. Here, I correct my error and show how it impacts my original findings. I argue that my main conclusions are unchanged. Furthermore, only two new findings contrast with those I presented earlier. First, changing those model details unrelated to the marginal fitness benefits of help does not, in turn, impact substantially the conflict that occurs between mates over the brood sex ratio (I had previously reported some noteworthy impact was possible). Second, help can reduce sex-ratio conflict between mates more effectively when breeders occur in smaller groups (previously, I had said this occurred in larger groups).}, }
@article {pmid36621654, year = {2023}, author = {Schradin, C}, title = {Traits don't evolve for the benefit of the species but because they increase individuals' inclusive fitness.}, journal = {Brain, behavior, and immunity}, volume = {109}, number = {}, pages = {89}, doi = {10.1016/j.bbi.2023.01.002}, pmid = {36621654}, issn = {1090-2139}, mesh = {Humans ; *Exercise ; Phenotype ; }, }
@article {pmid36617555, year = {2023}, author = {Robinson, SD and Schendel, V and Schroeder, CI and Moen, S and Mueller, A and Walker, AA and McKinnon, N and Neely, GG and Vetter, I and King, GF and Undheim, EAB}, title = {Intra-colony venom diversity contributes to maintaining eusociality in a cooperatively breeding ant.}, journal = {BMC biology}, volume = {21}, number = {1}, pages = {5}, pmid = {36617555}, issn = {1741-7007}, support = {DE160101142//Australian Research Council/ ; DP160104025//Australian Research Council/ ; DP190103787//Australian Research Council/ ; FF160100055//Australian Research Council/ ; APP1136889//Australian National Health &amp; Medical Research Council/ ; 287462//Norges Forskningsr&#xe5;d/ ; /WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Ants/genetics ; Venoms ; Australia ; Reproduction ; Social Behavior ; }, abstract = {BACKGROUND: Eusociality is widely considered to evolve through kin selection, where the reproductive success of an individual's close relative is favored at the expense of its own. High genetic relatedness is thus considered a prerequisite for eusociality. While ants are textbook examples of eusocial animals, not all ants form colonies of closely related individuals. One such example is the ectatommine ant Rhytidoponera metallica, which predominantly forms queen-less colonies that have such a low intra-colony relatedness that they have been proposed to represent a transient, unstable form of eusociality. However, R. metallica is among the most abundant and widespread ants on the Australian continent. This apparent contradiction provides an example of how inclusive fitness may not by itself explain the maintenance of eusociality and raises the question of what other selective advantages maintain the eusocial lifestyle of this species.<br><br>RESULTS: We provide a comprehensive portrait of the venom of R. metallica and show that the colony-wide venom consists of an exceptionally high diversity of functionally distinct toxins for an ant. These toxins have evolved under strong positive selection, which is normally expected to reduce genetic variance. Yet, R. metallica exhibits remarkable intra-colony variation, with workers sharing only a relatively small proportion of toxins in their venoms. This variation is not due to the presence of chemical castes, but has a genetic foundation that is at least in part explained by toxin allelic diversity.<br><br>CONCLUSIONS: Taken together, our results suggest that the toxin diversity contained in R. metallica colonies may be maintained by a form of group selection that selects for colonies that can exploit more resources and defend against a wider range of predators. We propose that increased intra-colony genetic variance resulting from low kinship may itself provide a selective advantage in the form of an expanded pharmacological venom repertoire. These findings provide an example of how group selection on adaptive phenotypes may contribute to maintaining eusociality where a prerequisite for kin selection is diminished.}, }
@article {pmid38682366, year = {2023}, author = {Liechty, T and Woo, M and Rice, LA and Chiu, CY and Kirkpatrick, S and Hankins, K and Hedgspeth, E and Nichols, A and Porter, C and Smeltzer, M and Adamson, B}, title = {Community Partners' Perspectives on Partnering With an Academic Research Team to Promote Disability-inclusive Fitness Programming.}, journal = {Progress in community health partnerships : research, education, and action}, volume = {17}, number = {3}, pages = {e11-e12}, pmid = {38682366}, issn = {1557-055X}, mesh = {Humans ; *Community-Based Participatory Research/organization &amp; administration ; *Disabled Persons ; Physical Fitness ; Health Promotion/organization &amp; administration ; Community-Institutional Relations ; Cooperative Behavior ; }, }
@article {pmid36579168, year = {2022}, author = {Kreider, JJ and Kramer, BH and Komdeur, J and Pen, I}, title = {The evolution of ageing in cooperative breeders.}, journal = {Evolution letters}, volume = {6}, number = {6}, pages = {450-459}, pmid = {36579168}, issn = {2056-3744}, abstract = {Cooperatively breeding animals live longer than their solitary counterparts. This has been suggested for birds, mole rats, and social insects. A common explanation for these long lifespans is that cooperative breeding evolves more readily in long-lived species because lower mortality reduces the rate of territory turnover and thus leads to a limitation of breeding territories. Here, we reverse this argument and show that-rather than being a cause for its evolution-long lifespans are an evolutionary consequence of cooperative breeding. In evolutionary individual-based simulations, we show that natural selection favors a delayed onset of senescence in cooperative breeders, relative to solitary breeders, because cooperative breeders have a delayed age of first reproduction as helpers wait in a reproductive queue to obtain breeder status. Especially long lifespans evolve in cooperative breeders in which queue positions depend on the helpers' age rank among the helpers within the breeding territory. Furthermore, we show that lower genetic relatedness among group members leads to the evolution of longer lifespans. This is because selection against higher mortality is weaker when mortality reduces competition for breeding between relatives. Our results link the evolutionary theory of ageing with kin selection theory, demonstrating that the evolution of ageing in cooperative breeders is driven by the timing of reproduction and kin structure within breeding territories.}, }
@article {pmid36521752, year = {2023}, author = {Bruckner, S and Straub, L and Neumann, P and Williams, GR}, title = {Negative but antagonistic effects of neonicotinoid insecticides and ectoparasitic mites Varroa destructor on Apis mellifera honey bee food glands.}, journal = {Chemosphere}, volume = {313}, number = {}, pages = {137535}, doi = {10.1016/j.chemosphere.2022.137535}, pmid = {36521752}, issn = {1879-1298}, mesh = {Bees ; Animals ; *Mites ; *Varroidae ; *Insecticides/toxicity ; *Honey ; Host-Parasite Interactions ; Neonicotinoids/toxicity ; }, abstract = {Collaborative brood care by workers is essential for the functionality of eusocial Apis mellifera honey bee colonies. The hypopharyngeal food glands of workers play a crucial role in this context. Even though there is consensus that ubiquitous ectoparasitic mites Varroa destructor and widespread insecticides, such as neonicotinoids, are major stressors for honey bee health, their impact alone and in combination on the feeding glands of workers is poorly understood. Here, we show that combined exposure to V. destructor and neonicotinoids antagonistically interacted on hypopharyngeal gland size, yet they did not interact on emergence body mass or survival. While the observed effects of the antagonistic interaction were less negative than expected based on the sum of the individual effects, hypopharyngeal gland size was still significantly reduced. Alone, V. destructor parasitism negatively affected emergence body mass, survival, and hypopharyngeal gland size, whereas neonicotinoid exposure reduced hypopharyngeal gland size only. Since size is associated with hypopharyngeal gland functionality, a reduction could result in inadequate brood care. As cooperative brood care is a cornerstone of eusociality, smaller glands could have adverse down-stream effects on inclusive fitness of honey bee colonies. Therefore, our findings highlight the need to further study how ubiquitous stressors like V. destructor and neonicotinoids interact to affect honey bees.}, }
@article {pmid36514956, year = {2022}, author = {Davidian, E and Höner, OP}, title = {Kinship and similarity drive coordination of breeding-group choice in male spotted hyenas.}, journal = {Biology letters}, volume = {18}, number = {12}, pages = {20220402}, pmid = {36514956}, issn = {1744-957X}, mesh = {Animals ; Female ; Male ; *Hyaenidae/genetics ; }, abstract = {When and where animals reproduce influences the social, demographic and genetic properties of the groups and populations they live in. We examined the extent to which male spotted hyenas (Crocuta crocuta) coordinate their breeding-group choice. We tested whether their propensity to settle in the same group is shaped by passive processes driven by similarities in their socio-ecological background and genotype or by an adaptive process driven by kin selection. We compared the choices of 148 pairs of same-cohort males that varied in similarity and kinship. We found strong support for both processes. Coordination was highest (70% of pairs) for littermates, who share most cumulative similarity, lower (36%) among peers born in the same group to different mothers, and lowest (7%) among strangers originating from different groups and mothers. Consistent with the kin selection hypothesis, the propensity to choose the same group was density dependent for full siblings and close kin, but not distant kin. Coordination increased as the number of breeding females and male competitors in social groups increased, i.e. when costs of kin competition over mates decreased and benefits of kin cooperation increased. Our results contrast with the traditional view that breeding-group choice and dispersal are predominantly solitary processes.}, }
@article {pmid36502806, year = {2023}, author = {Wu, R and Pang, J and Xu, Z and Wu, X and Wang, W and Zheng, Y and Yang, S and Wei, W}, title = {Adolescence Predatory Risk Alters Social Behaviors and Cognitive Ability and Central Oxytocin and Vasopressin Expression in Adult Brandt's Voles.}, journal = {Neuroendocrinology}, volume = {113}, number = {5}, pages = {519-534}, doi = {10.1159/000528608}, pmid = {36502806}, issn = {1423-0194}, mesh = {Male ; Animals ; Female ; *Oxytocin/metabolism ; *Hypothalamo-Hypophyseal System/metabolism ; Pituitary-Adrenal System ; Arvicolinae/metabolism ; Social Behavior ; Arginine Vasopressin/metabolism ; Cognition ; }, abstract = {INTRODUCTION: Stress during adolescence causes long-term behavioral changes in adulthood. We previously found that adolescent exposure to predatory risk augments adolescent social contact and adult parental behavior in Brandt's voles (Lasiopodomys brandtii).<br><br>METHODS: Here, we determined whether this experience alters sexual behavior, pair-bond formation, and recognition ability as well as basal HPA axis activity, central oxytocin (OT), and arginine-vasopressin (AVP) expression in adulthood.<br><br>RESULTS: In the social interaction test, repeated cat odor (CO) exposure enhanced the frequency of lordosis by female voles toward an unfamiliar opposite-sex conspecific. CO voles preferred to engage with their partners after 48-h cohabitation whereas the control groups did not, which may reflect stable pair bonds in the CO treatment group. Furthermore, adolescent exposure to CO inhibited novel object recognition and place recognition ability, while it influenced social recognition only among adult males. No effect of adolescent CO exposure was observed for basal HPA axis activity, showing a habituation effect. Finally, we found that CO exposure increased OT and decreased AVP expression in the hypothalamus, including the paraventricular nucleus and anterior hypothalamus. The levels of OT in the medial amygdala were lower, and AVP in the lateral septum was higher in CO voles compared with the control.<br><br>CONCLUSION: These findings demonstrate that adolescent exposure to predator risk promotes adult reproductive behavior of Brandt's voles. Deficits in recognition ability may necessitate alterations in reproductive strategies to enhance inclusive fitness. OT and AVP systems may play a modulatory role in the alteration of social behaviors elicited by adolescent predatory risk.}, }
@article {pmid36483755, year = {2022}, author = {Boon-Falleur, M and Dormont, B and Chevallier, C}, title = {Does higher perceived risk of morbidity and mortality decrease risk-taking?.}, journal = {Royal Society open science}, volume = {9}, number = {12}, pages = {220486}, pmid = {36483755}, issn = {2054-5703}, abstract = {Previous studies have shown that people change their behaviour in response to negative shocks such as economic downturns or natural catastrophes. Indeed, the optimal behaviour in terms of inclusive fitness often varies according to a number of parameters, such as the level of mortality risk in the environment. Beyond unprecedented restrictions in everyday life, the COVID-19 pandemic has profoundly affected people's environment. In this study, we investigated how people form their perception of morbidity and mortality risk associated with COVID-19 and how this perception in turn affects psychological traits, such as risk-taking and patience. We analysed data from a large survey conducted during the first wave in France on 3353 nationally representative people. We found that people use public information on COVID-19 deaths in the area where they live to form their perceived morbidity and mortality risk. Using a structural model approach to lift endogeneity concerns, we found that higher perceived morbidity and mortality risk increases risk aversion. We also found that higher perceived morbidity and mortality risk leads to less patience, although this was only observed for high levels of perceived risk. Our results suggest that people adapt their behaviour to anticipated negative health shocks, namely the risk of becoming sick or dying of COVID-19.}, }
@article {pmid36457233, year = {2023}, author = {da Silva, J}, title = {The kin selection theory of genomic imprinting and modes of reproduction in the eusocial Hymenoptera.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {98}, number = {2}, pages = {677-695}, doi = {10.1111/brv.12925}, pmid = {36457233}, issn = {1469-185X}, mesh = {Animals ; Male ; *Genomic Imprinting ; *Ants/genetics ; Parthenogenesis ; Reproduction ; Sex Ratio ; Mammals ; }, abstract = {Genomic imprinting is known from flowering plants and mammals but has not been confirmed for the Hymenoptera even though the eusocial Hymenoptera are prime candidates for this peculiar form of gene expression. Here, the kin selection theory of genomic imprinting is reviewed and applied to the eusocial Hymenoptera. The evidence for imprinting in eusocial Hymenoptera with the typical mode of reproduction, involving the sexual production of diploid female offspring, which develop into workers or gynes, and the arrhenotokous parthenogenesis of haploid males, is also reviewed briefly. However, the focus of this review is how atypical modes of reproduction, involving thelytokous parthenogenesis, hybridisation and androgenesis, may also select for imprinting. In particular, naturally occurring hybridisation in several genera of ants may provide useful tests of the role of kin selection in the evolution of imprinting. Hybridisation is expected to disrupt the coadaptation of antagonistically imprinted loci, and thus affect the phenotypes of hybrids. Some of the limited data available on hybrid worker reproduction and on colony sex ratios support predictions about patterns of imprinting derived from kin selection theory.}, }
@article {pmid36425073, year = {2022}, author = {Card, DC and Van Camp, AG and Santonastaso, T and Jensen-Seaman, MI and Anthony, NM and Edwards, SV}, title = {Structure and evolution of the squamate major histocompatibility complex as revealed by two Anolis lizard genomes.}, journal = {Frontiers in genetics}, volume = {13}, number = {}, pages = {979746}, pmid = {36425073}, issn = {1664-8021}, abstract = {The major histocompatibility complex (MHC) is an important genomic region for adaptive immunity and has long been studied in ecological and evolutionary contexts, such as disease resistance and mate and kin selection. The MHC has been investigated extensively in mammals and birds but far less so in squamate reptiles, the third major radiation of amniotes. We localized the core MHC genomic region in two squamate species, the green anole (Anolis carolinensis) and brown anole (A. sagrei), and provide the first detailed characterization of the squamate MHC, including the presence and ordering of known MHC genes in these species and comparative assessments of genomic structure and composition in MHC regions. We find that the Anolis MHC, located on chromosome 2 in both species, contains homologs of many previously-identified mammalian MHC genes in a single core MHC region. The repetitive element composition in anole MHC regions was similar to those observed in mammals but had important distinctions, such as higher proportions of DNA transposons. Moreover, longer introns and intergenic regions result in a much larger squamate MHC region (11.7 Mb and 24.6 Mb in the green and brown anole, respectively). Evolutionary analyses of MHC homologs of anoles and other representative amniotes uncovered generally monophyletic relationships between species-specific homologs and a loss of the peptide-binding domain exon 2 in one of two mhc2β gene homologs of each anole species. Signals of diversifying selection in each anole species was evident across codons of mhc1, many of which appear functionally relevant given known structures of this protein from the green anole, chicken, and human. Altogether, our investigation fills a major gap in understanding of amniote MHC diversity and evolution and provides an important foundation for future squamate-specific or vertebrate-wide investigations of the MHC.}, }
@article {pmid36424400, year = {2022}, author = {Kristensen, NP and Ohtsuki, H and Chisholm, RA}, title = {Ancestral social environments plus nonlinear benefits can explain cooperation in human societies.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {20252}, pmid = {36424400}, issn = {2045-2322}, support = {WBS A-0004766-00-00//Ministry of Education - Singapore/ ; JP19H04431//Japan Society for the Promotion of Science/ ; }, mesh = {Humans ; *Game Theory ; *Cooperative Behavior ; Biological Evolution ; Social Environment ; }, abstract = {Human cooperation (paying a cost to benefit others) is puzzling from a Darwinian perspective, particularly in groups with strangers who cannot repay nor are family members. The beneficial effects of cooperation typically increase nonlinearly with the number of cooperators, e.g., increasing returns when cooperation is low and diminishing returns when cooperation is high. Such nonlinearity can allow cooperation between strangers to persist evolutionarily if a large enough proportion of the population are already cooperators. However, if a lone cooperator faces a conflict between the group's and its own interests (a social dilemma), that raises the question of how cooperation arose in the first place. We use a mathematically tractable evolutionary model to formalise a chronological narrative that has previously only been investigated verbally: given that ancient humans interacted mostly with family members (genetic homophily), cooperation evolved first by kin selection, and then persisted in situations with nonlinear benefits as homophily declined or even if interactions with strangers became the norm. The model also predicts the coexistence of cooperators and defectors observed in the human population (polymorphism), and may explain why cooperators in behavioural experiments prefer to condition their contribution on the contributions of others (conditional cooperation in public goods games).}, }
@article {pmid36421825, year = {2022}, author = {Kyrgiafini, MA and Giannoulis, T and Moutou, KA and Mamuris, Z}, title = {Investigating the Impact of a Curse: Diseases, Population Isolation, Evolution and the Mother's Curse.}, journal = {Genes}, volume = {13}, number = {11}, pages = {}, pmid = {36421825}, issn = {2073-4425}, mesh = {Male ; Female ; Humans ; *Mothers ; DNA, Mitochondrial/genetics ; Maternal Inheritance/genetics ; *Genome, Mitochondrial/genetics ; Mitochondria/genetics ; }, abstract = {The mitochondrion was characterized for years as the energy factory of the cell, but now its role in many more cellular processes is recognized. The mitochondrion and mitochondrial DNA (mtDNA) also possess a set of distinct properties, including maternal inheritance, that creates the Mother's Curse phenomenon. As mtDNA is inherited from females to all offspring, mutations that are harmful to males tend to accumulate more easily. The Mother's Curse is associated with various diseases, and has a significant effect on males, in many cases even affecting their reproductive ability. Sometimes, it even leads to reproductive isolation, as in crosses between different populations, the mitochondrial genome cannot cooperate effectively with the nuclear one resulting in a mito-nuclear incompatibility and reduce the fitness of the hybrids. This phenomenon is observed both in the laboratory and in natural populations, and have the potential to influence their evolution and speciation. Therefore, it turns out that the study of mitochondria is an exciting field that finds many applications, including pest control, and it can shed light on the molecular mechanism of several diseases, improving successful diagnosis and therapeutics. Finally, mito-nuclear co-adaptation, paternal leakage, and kin selection are some mechanisms that can mitigate the impact of the Mother's Curse.}, }
@article {pmid36420711, year = {2022}, author = {Higham, JP}, title = {Kin selection spreads.}, journal = {eLife}, volume = {11}, number = {}, pages = {}, pmid = {36420711}, issn = {2050-084X}, mesh = {Humans ; Infant ; *Mother-Child Relations ; *Sibling Relations ; Female ; }, abstract = {By spending more time around infants which physically resemble their own, mandrill mothers may increase how frequently their offspring interact with their paternal half siblings.}, }
@article {pmid36401071, year = {2023}, author = {Whyte, S and Chan, HF and Ferguson, N and Godwin, M and Hammarberg, K and Torgler, B}, title = {Understanding the Reasons Why Men and Women Do Not Donate Gametes.}, journal = {Reproductive sciences (Thousand Oaks, Calif.)}, volume = {30}, number = {5}, pages = {1651-1659}, pmid = {36401071}, issn = {1933-7205}, mesh = {Male ; Female ; Humans ; *Oocyte Donation ; *Semen ; Tissue Donors ; Spermatozoa ; Oocytes ; Surveys and Questionnaires ; }, abstract = {The global under-supply of sperm and oocyte donors is a serious concern for assisted reproductive medicine. Research has explored self-selected populations of gamete donors and their ex-post rationalisations of why they chose to donate. However, such studies may not provide the necessary insight into why the majority of people do not donate. Utilising the unique open form responses of a large sample (n = 1035) of online survey respondents, we examine the reasons participants cite when asked: "Why haven't you donated your sperm/eggs?." We categorise these responses into four core themes (conditional willingness, barriers, unconsidered, and conscientious objector) and eleven lower-order themes. We find that, on average, women are more conditionally willing (8.2% difference; p = 0.008) to participate in gamete donation than men. We also find that women are more likely than men to justify their non-donation based on their reproductive history (21.3% difference; p = 0.000) or kin selection and inclusive fitness (5.7% difference; p = 0.008). However, compared to women, men are more likely to validate their non-donation based on sociocultural or social norms (6% difference; p = 0.000) or religion (1.7% difference; p = 0.030). That so many of our study participants report in-principal willingness for future participation in gamete donation speaks to the need for increased research on understanding non-donor population preferences, motivations, and behaviours.}, }
@article {pmid36377479, year = {2022}, author = {Charpentier, MJE and Poirotte, C and Roura-Torres, B and Amblard-Rambert, P and Willaume, E and Kappeler, PM and Rousset, F and Renoult, JP}, title = {Mandrill mothers associate with infants who look like their own offspring using phenotype matching.}, journal = {eLife}, volume = {11}, number = {}, pages = {}, pmid = {36377479}, issn = {2050-084X}, mesh = {Humans ; Adult ; Female ; Animals ; *Mandrillus ; Social Behavior ; Phenotype ; Cooperative Behavior ; Maternal Behavior ; }, abstract = {Behavioral discrimination of kin is a key process structuring social relationships in animals. In this study, we provide evidence for discrimination towards non-kin by third-parties through a mechanism of phenotype matching. In mandrills, we recently demonstrated increased facial resemblance among paternally related juvenile and adult females indicating adaptive opportunities for paternal kin recognition. Here, we hypothesize that mandrill mothers use offspring's facial resemblance with other infants to guide offspring's social opportunities towards similar-looking ones. Using deep learning for face recognition in 80 wild mandrill infants, we first show that infants sired by the same father resemble each other the most, independently of their age, sex or maternal origin, extending previous results to the youngest age class. Using long-term behavioral observations on association patterns, and controlling for matrilineal origin, maternal relatedness and infant age and sex, we then show, as predicted, that mothers are spatially closer to infants that resemble their own offspring more, and that this maternal behavior leads to similar-looking infants being spatially associated. We then discuss the different scenarios explaining this result, arguing that an adaptive maternal behavior is a likely explanation. In support of this mechanism and using theoretical modeling, we finally describe a plausible evolutionary process whereby mothers gain fitness benefits by promoting nepotism among paternally related infants. This mechanism, that we call 'second-order kin selection', may extend beyond mother-infant interactions and has the potential to explain cooperative behaviors among non-kin in other social species, including humans.}, }
@article {pmid36349451, year = {2023}, author = {Penndorf, J and Ewart, KM and Klump, BC and Martin, JM and Aplin, LM}, title = {Social network analysis reveals context-dependent kin relationships in wild sulphur-crested cockatoos Cacatua galerita.}, journal = {The Journal of animal ecology}, volume = {92}, number = {1}, pages = {171-182}, doi = {10.1111/1365-2656.13839}, pmid = {36349451}, issn = {1365-2656}, mesh = {Female ; Animals ; *Cockatoos ; Social Network Analysis ; *Parrots ; Aggression ; Sulfur ; }, abstract = {A preference to associate with kin facilitates inclusive fitness benefits, and increased tolerance or cooperation between kin may be an added benefit of group living. Many species exhibit preferred associations with kin; however, it is often hard to disentangle active preferences from passive overlap, for example caused by limited dispersal or inheritance of social position. Many parrots exhibit social systems consisting of pair-bonded individuals foraging in variably sized fission-fusion flocks within larger communal roosts of hundreds of individuals. Previous work has shown that, despite these fission-fusion dynamics, individuals can exhibit long-term preferred foraging associations outside their pair bonds. Yet the underlying drivers of these social preferences remain largely unknown. In this study, we use a network approach to examine the influence of kinship on social associations and interactions in wild, communally roosting sulphur-crested cockatoos, Cacatua galerita. We recorded roost co-membership, social associations and interactions in 561 individually marked birds across three neighbouring roosts. We then collected genetic samples from 205 cockatoos, and conducted a relationship analysis to construct a kinship network. Finally, we tested correlations between kinship and four social networks: association, affiliative, low-intensity aggression and high-intensity aggression. Our result showed that while roosting groups were clearly defined, they showed little genetic differentiation or kin structuring. Between roost movement was high, with juveniles, especially females, repeatedly moving between roosts. Both within roosting communities, and when visiting different roosts, individuals preferentially associated with kin. Supporting this, individuals were also more likely to allopreen kin. However, contrary to expectation, individuals preferred to direct aggression towards kin, with this effect only observed when individuals shared roost membership. By measuring social networks within and between large roosting groups, we could remove potential effects of passive spatial overlap on kin structuring. Our study reveals that sulphur-crested cockatoos actively prefer to associate with kin, both within and between roosting groups. By examining this across different interaction types, we further demonstrate that sulphur-crested cockatoos exhibit behavioural and context-dependent interaction rules towards kin. Our results help reveal the drivers of social association in this species, while adding to the evidence for social complexity in parrots.}, }
@article {pmid36346221, year = {2022}, author = {Han, B and Wei, Q and Amiri, E and Hu, H and Meng, L and Strand, MK and Tarpy, DR and Xu, S and Li, J and Rueppell, O}, title = {The molecular basis of socially induced egg-size plasticity in honey bees.}, journal = {eLife}, volume = {11}, number = {}, pages = {}, pmid = {36346221}, issn = {2050-084X}, mesh = {Female ; Bees ; Animals ; *Reproduction ; *Oviposition ; Ovary ; Eggs ; }, abstract = {Reproduction involves the investment of resources into offspring. Although variation in reproductive effort often affects the number of offspring, adjustments of propagule size are also found in numerous species, including the Western honey bee, Apis mellifera. However, the proximate causes of these adjustments are insufficiently understood, especially in oviparous species with complex social organization in which adaptive evolution is shaped by kin selection. Here, we show in a series of experiments that queens predictably and reversibly increase egg size in small colonies and decrease egg size in large colonies, while their ovary size changes in the opposite direction. Additional results suggest that these effects cannot be solely explained by egg-laying rate and are due to the queens' perception of colony size. Egg-size plasticity is associated with quantitative changes of 290 ovarian proteins, most of which relate to energy metabolism, protein transport, and cytoskeleton. Based on functional and network analyses, we further study the small GTPase Rho1 as a candidate regulator of egg size. Spatio-temporal expression analysis via RNAscope and qPCR supports an important role of Rho1 in egg-size determination, and subsequent RNAi-mediated gene knockdown confirmed that Rho1 has a major effect on egg size in honey bees. These results elucidate how the social environment of the honey bee colony may be translated into a specific cellular process to adjust maternal investment into eggs. It remains to be studied how widespread this mechanism is and whether it has consequences for population dynamics and epigenetic influences on offspring phenotype in honey bees and other species.}, }
@article {pmid36344830, year = {2023}, author = {Cordoni, G and Comin, M and Collarini, E and Robino, C and Chierto, E and Norscia, I}, title = {Domestic pigs (Sus scrofa) engage in non-random post-conflict affiliation with third parties: cognitive and functional implications.}, journal = {Animal cognition}, volume = {26}, number = {2}, pages = {687-701}, pmid = {36344830}, issn = {1435-9456}, mesh = {Animals ; Swine ; *Social Behavior ; *Behavior, Animal/physiology ; Aggression/psychology ; Sus scrofa ; Cognition ; }, abstract = {In social mammals, conflict resolution involves the reunion of former opponents (aggressor and victim) after an aggressive event (reconciliation) or post-conflict triadic contacts with a third party, started by either opponent (solicited-TSC) or spontaneously offered by the third party (unsolicited-TUC). These post-conflict strategies can serve different functions, including consolation (specifically when TUCs reduce the victim's anxiety). We investigated the possible presence and modulating factors of such strategies on semi-free ranging pigs (Sus scrofa; N = 104), housed at the ethical farm Parva Domus (Cavagnolo, Italy). Kinship was known. Reconciliation was present and mainly occurred between weakly related pigs to possibly improve tolerant cohabitation. Triadic contacts (all present except aggressor TSCs) mostly occurred between close kin. TSCs enacted by victims reduced neither their post-conflict anxiety behaviors nor further attacks by the previous aggressor, possibly because TSCs remained largely unreciprocated. TUCs towards aggressors did not reduce aggressor post-conflict anxiety but limited aggression redirection towards third parties. TUCs towards the victim reduced the victim but not the third-party's anxiety. However, TUCs may also provide inclusive fitness benefits to third parties by benefiting close kin. In sum, pigs engaged in non-random solicited/unsolicited triadic contacts, which suggests that pigs might possess socio-emotional regulation abilities to change their own or others' experience and elements of social appraisal, necessary to detect the emotional arousal of relevant others and (in case of TUCs) take the agency to restore homeostasis.}, }
@article {pmid36343483, year = {2022}, author = {Wang, X and Harrison, A}, title = {Non-kin selection enhances complexity in cooperation: A unified quantitative law.}, journal = {Computational biology and chemistry}, volume = {101}, number = {}, pages = {107782}, doi = {10.1016/j.compbiolchem.2022.107782}, pmid = {36343483}, issn = {1476-928X}, support = {BB/E001742/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Humans ; *Biological Evolution ; Genotype ; }, abstract = {How cooperation evolves in the presence of selfishness is a core problem in evolutionary biology. Selfish individuals tend to benefit themselves, which makes it harder to maintain cooperation between unrelated individuals and for living systems to evolve towards complex organizations. The general evolutionary model presented here identifies that non-kin selection is the root cause for cooperation between unrelated individuals and can enable and maintain higher complexity of biological organizations (the coexistence of more individuals of different types). The maintained number of genotypes within a cooperation organization is shown to follow a universal exponential law as a quantitative function of the population size and non-kin selection strength, showing a gene-pool-size invariance. Our results highlight that non-kin selection may be a hallmark of biological evolution, and play an important role in shaping life's potentials.}, }
@article {pmid36333950, year = {2023}, author = {Hammer, TJ and Easton-Calabria, A and Moran, NA}, title = {Microbiome assembly and maintenance across the lifespan of bumble bee workers.}, journal = {Molecular ecology}, volume = {32}, number = {3}, pages = {724-740}, pmid = {36333950}, issn = {1365-294X}, support = {R35 GM131738/GM/NIGMS NIH HHS/United States ; R35GM131738/NH/NIH HHS/United States ; 2018-08156//National Institute of Food and Agriculture/ ; }, mesh = {Humans ; Bees/genetics ; Animals ; Longevity/genetics ; RNA, Ribosomal, 16S/genetics ; *Microbiota/genetics ; *Gastrointestinal Microbiome/genetics ; Bacteria/genetics ; }, abstract = {How a host's microbiome changes over its lifespan can influence development and ageing. As these temporal patterns have only been described in detail for a handful of hosts, an important next step is to compare microbiome succession more broadly and investigate why it varies. Here we characterize the temporal dynamics and stability of the bumble bee worker gut microbiome. Bumble bees have simple and host-specific gut microbiomes, and their microbial dynamics may influence health and pollination services. We used 16S rRNA gene sequencing, quantitative PCR and metagenomics to characterize gut microbiomes over the lifespan of Bombus impatiens workers. We also sequenced gut transcriptomes to examine host factors that may control the microbiome. At the community level, microbiome assembly is highly predictable and similar to patterns of primary succession observed in the human gut. However, at the strain level, partitioning of bacterial variants among colonies suggests stochastic colonization events similar to those observed in flies and nematodes. We also find strong differences in temporal dynamics among symbiont species, suggesting ecological differences among microbiome members in colonization and persistence. Finally, we show that both the gut microbiome and host transcriptome-including expression of key immunity genes-stabilize, as opposed to senesce, with age. We suggest that in highly social groups such as bumble bees, maintenance of both microbiomes and immunity contribute to inclusive fitness, and thus remain under selection even in old age. Our findings provide a foundation for exploring the mechanisms and functional outcomes of bee microbiome succession.}, }
@article {pmid36330299, year = {2022}, author = {Biernaskie, JM}, title = {Kin selection theory and the design of cooperative crops.}, journal = {Evolutionary applications}, volume = {15}, number = {10}, pages = {1555-1564}, pmid = {36330299}, issn = {1752-4571}, abstract = {In agriculture and plant breeding, plant traits may be favoured because they benefit neighbouring plants and ultimately increase total crop yield. This idea of promoting cooperation among crop plants has existed almost as long as W.D. Hamilton's inclusive fitness (kin selection) theory, the leading framework for explaining cooperation in biology. However, kin selection thinking has not been adequately applied to the idea of cooperative crops. Here, I give an overview of modern kin selection theory and consider how it explains three key strategies for designing cooperative crops: (1) selection for a less-competitive plant type (a 'communal ideotype'); (2) group-level selection for yield; and (3) exploiting naturally selected cooperation. The first two strategies, using artificial selection, have been successful in the past but suffer from limitations that could hinder future progress. Instead, I propose an alternative strategy and a new 'colonial ideotype' that exploits past natural selection for cooperation among the modules (e.g., branches or stems) of individual plants. More generally, I suggest that Hamiltonian agriculture-a kin selection view of agriculture and plant breeding-transforms our understanding of how to improve crops of the future.}, }
@article {pmid36259168, year = {2022}, author = {Barreto Filho, MM and Vieira, HH and Morris, JJ and Bagatini, IL}, title = {Species-specific effects and the ecological role of programmed cell death in the microalgae Ankistrodesmus (Sphaeropleales, Selenastraceae).}, journal = {Biology letters}, volume = {18}, number = {10}, pages = {20220259}, pmid = {36259168}, issn = {1744-957X}, mesh = {*Microalgae ; Phytoplankton ; Apoptosis/physiology ; Species Specificity ; Nitrogen ; }, abstract = {Reports of programmed cell death (PCD) in phytoplankton raise questions about the ecological evolutionary role of cell death in these organisms. We induced PCD by nitrogen deprivation and unregulated cell death (non-PCD) in one strain of the green microalga Ankistrodesmus densus and investigated the effects of the cell death supernatants on phylogenetically related co-occurring organisms using growth rates and maximum biomass as proxies of fitness. PCD-released materials from A. densus CCMA-UFSCar-3 significantly increased growth rates of two conspecific strains compared to healthy culture (HC) supernatants and improved the maximum biomass of all A. densus strains compared to related species. Although growth rates of non-A. densus with PCD supernatants were not statistically different from HC treatment, biomass gain was significantly reduced. Thus, the organic substances released by PCD, possibly nitrogenous compounds, could promote conspecific growth. These results support the argument that PCD may differentiate species or subtypes and increases inclusive fitness in this model unicellular chlorophyte. Further research, however, is needed to identify the responsible molecules and how they interact with cells to provide the PCD benefits.}, }
@article {pmid36251655, year = {2022}, author = {Khadraoui, M and Merritt, JR and Hoekstra, HE and Bendesky, A}, title = {Post-mating parental behavior trajectories differ across four species of deer mice.}, journal = {PloS one}, volume = {17}, number = {10}, pages = {e0276052}, pmid = {36251655}, issn = {1932-6203}, support = {/HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; Female ; Male ; Paternal Behavior ; *Peromyscus ; Pregnancy ; *Reproduction ; }, abstract = {Among species, parental behaviors vary in their magnitude, onset relative to reproduction, and sexual dimorphism. In deer mice (genus Peromyscus), while most species are promiscuous with low paternal care, monogamy and biparental care have evolved at least twice under different ecological conditions. Here, in a common laboratory setting, we monitored parental behaviors of males and females of two promiscuous (eastern deer mouse P. maniculatus and white-footed mouse P. leucopus) and two monogamous (oldfield mouse P. polionotus and California mouse P. californicus) species from before mating to after giving birth. In the promiscuous species, females showed parental behaviors largely after parturition, while males showed little parental care. In contrast, both sexes of monogamous species performed parental behaviors. However, while oldfield mice began to display parental behaviors before mating, California mice showed robust parental care behaviors only postpartum. These different parental-care trajectories in the two monogamous species align with their socioecology. Oldfield mice have overlapping home ranges with relatives, so infants they encounter, even if not their own, are likely to be closely related. By contrast, California mice disperse longer distances into exclusive territories with possibly unrelated neighbors, decreasing the inclusive fitness benefits of caring for unfamiliar pups before parenthood. Together, we find that patterns of parental behaviors in Peromyscus are consistent with predictions from inclusive fitness theory.}, }
@article {pmid36218362, year = {2022}, author = {Liu, Y and Huang, R and Chen, Y and Miao, Y and Štefanič, P and Mandic-Mulec, I and Zhang, R and Shen, Q and Xu, Z}, title = {Involvement of Flagellin in Kin Recognition between Bacillus velezensis Strains.}, journal = {mSystems}, volume = {7}, number = {6}, pages = {e0077822}, pmid = {36218362}, issn = {2379-5077}, mesh = {*Flagellin/genetics ; *Bacillus/genetics ; Polymorphism, Genetic ; Amino Acid Sequence ; }, abstract = {Kin discrimination in nature is an effective way for bacteria to stabilize population cooperation and maintain progeny benefits. However, so far, the research on kin discrimination for Bacillus still has concentrated on "attack and defense" between cells and diffusion-dependent molecular signals of quorum sensing, kin recognition in Bacillus, however, has not been reported. To determine whether flagellar is involve in the kin recognition of Bacillus, we constructed Bacillus velezensis SQR9 assembled with flagellin of its kin and non-kin strains, and performed a swarm boundary assay with SQR9, then analyzed sequence variation of flagellin and other flagellar structural proteins in B. velezensis genus. Our results showed that SQR9 assembled with flagellin of non-kin strains was more likely to form a border phenotype with wild-type strain SQR9 in swarm assay than that of kin strains, and that non-kin strains had greater variation in flagellin than kin strains. In B. velezensis, these variations in flagellin were prevalent and had evolved significantly faster than other flagellar structural proteins. Therefore, we proposed that flagellin is an effective tool partly involved in the kin recognition of B. velezensis strains. IMPORTANCE Kin selection plays an important role in stabilizing population cooperation and maintaining the progeny benefits for bacteria in nature. However, to date, the role of flagellin in kin recognition in Bacillus has not been reported. By using rhizospheric Bacillus velezensis SQR9, we accomplished flagellin region interchange among its related strains, and show that flagellin acts as a mediator to distinguish kin from non-kin in B. velezensis. We demonstrated the polymorphism of flagellin in B. velezensis through alignment analysis of flagellin protein sequences. Therefore, it was proposed that flagellin was likely to be an effective tool for mediating kin recognition in B. velezensis.}, }
@article {pmid36196551, year = {2022}, author = {García-Ruiz, I and Taborsky, M}, title = {Group augmentation on trial: helpers in small groups enhance antipredator defence of eggs.}, journal = {Biology letters}, volume = {18}, number = {10}, pages = {20220170}, pmid = {36196551}, issn = {1744-957X}, mesh = {Altruism ; Animals ; *Cichlids ; Cooperative Behavior ; *Helping Behavior ; Reproduction ; Sand ; }, abstract = {Mechanisms selecting for the evolution of cooperative breeding are hotly debated. While kin selection theory has been the central paradigm to explain the seemingly altruistic behaviour of non-reproducing helpers, it is increasingly recognized that direct fitness benefits may be highly relevant. The group augmentation hypothesis proposes that alloparental care may evolve to enhance group size when larger groups yield increased survival and/or reproductive success. However, there is a lack of empirical tests. Here we use the cooperatively breeding cichlid fish Neolamprologus pulcher, in which group size predicts survival and group stability, to test this hypothesis experimentally by prompting two cooperative tasks: defence against an egg predator and digging out sand from the breeding shelter. We controlled for alternative mechanisms such as kin selection, load lightening and coercion. As predicted by the group augmentation hypothesis, helpers increased defence against an egg predator in small compared with large groups. This difference was only evident in large helpers owing to size-specific task specialization. Furthermore, helpers showed more digging effort in the breeding chamber compared with alternative personal shelters, indicating that digging is an altruistic service to the dominant breeders.}, }
@article {pmid36191234, year = {2022}, author = {Scott, TJ}, title = {Cooperation loci are more pleiotropic than private loci in the bacterium Pseudomonas aeruginosa.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, number = {41}, pages = {e2214827119}, pmid = {36191234}, issn = {1091-6490}, mesh = {*Genetic Pleiotropy ; Mutation ; *Pseudomonas aeruginosa/genetics/metabolism ; }, abstract = {Pleiotropy may affect the maintenance of cooperation by limiting cheater mutants if such mutants lose other important traits. If pleiotropy limits cheaters, selection may favor cooperation loci that are more pleiotropic. However, the same should not be true for private loci with functions unrelated to cooperation. Pleiotropy in cooperative loci has mostly been studied with single loci and has not been measured on a wide scale or compared to a suitable set of control loci with private functions. I remedy this gap by comparing genomic measures of pleiotropy in previously identified cooperative and private loci in Pseudomonas aeruginosa. I found that cooperative loci in P. aeruginosa tended to be more pleiotropic than private loci according to the number of protein-protein interactions, the number of gene ontology terms, and gene expression specificity. These results show that pleiotropy may be a general way to limit cheating and that cooperation may shape pleiotropy in the genome.}, }
@article {pmid36134889, year = {2022}, author = {Grebe, NM and Hirwa, JP and Stoinski, TS and Vigilant, L and Rosenbaum, S}, title = {Mountain gorillas maintain strong affiliative biases for maternal siblings despite high male reproductive skew and extensive exposure to paternal kin.}, journal = {eLife}, volume = {11}, number = {}, pages = {}, pmid = {36134889}, issn = {2050-084X}, mesh = {Animals ; Bias ; Family ; *Gorilla gorilla ; Humans ; Male ; Mammals ; Primates ; *Reproduction ; Siblings ; }, abstract = {Evolutionary theories predict that sibling relationships will reflect a complex balance of cooperative and competitive dynamics. In most mammals, dispersal and death patterns mean that sibling relationships occur in a relatively narrow window during development and/or only with same-sex individuals. Besides humans, one notable exception is mountain gorillas, in which non-sex-biased dispersal, relatively stable group composition, and the long reproductive tenures of alpha males mean that animals routinely reside with both maternally and paternally related siblings, of the same and opposite sex, throughout their lives. Using nearly 40,000 hr of behavioral data collected over 14 years on 699 sibling and 1235 non-sibling pairs of wild mountain gorillas, we demonstrate that individuals have strong affiliative preferences for full and maternal siblings over paternal siblings or unrelated animals, consistent with an inability to discriminate paternal kin. Intriguingly, however, aggression data imply the opposite. Aggression rates were statistically indistinguishable among all types of dyads except one: in mixed-sex dyads, non-siblings engaged in substantially more aggression than siblings of any type. This pattern suggests mountain gorillas may be capable of distinguishing paternal kin but nonetheless choose not to affiliate with them over non-kin. We observe a preference for maternal kin in a species with a high reproductive skew (i.e. high relatedness certainty), even though low reproductive skew (i.e. low relatedness certainty) is believed to underlie such biases in other non-human primates. Our results call into question reasons for strong maternal kin biases when paternal kin are identifiable, familiar, and similarly likely to be long-term groupmates, and they may also suggest behavioral mismatches at play during a transitional period in mountain gorilla society.}, }
@article {pmid36129331, year = {2024}, author = {Kulich, HR and Bass, SR and Piva, SR and Nindl, B and Koontz, AM}, title = {Preliminary feasibility and acute physiological effects of a single session of upper limb vibration training for persons with spinal cord injury.}, journal = {The journal of spinal cord medicine}, volume = {47}, number = {4}, pages = {511-521}, pmid = {36129331}, issn = {2045-7723}, support = {TL1 TR001858/TR/NCATS NIH HHS/United States ; }, mesh = {Humans ; *Spinal Cord Injuries/rehabilitation ; *Vibration/therapeutic use ; Male ; Adult ; Female ; *Upper Extremity/physiopathology ; Middle Aged ; *Exercise Therapy/methods ; Feasibility Studies ; Resistance Training/methods ; }, abstract = {CONTEXT: Strong upper limb musculature is essential for persons with spinal cord injury (SCI) to operate a manual wheelchair and live independently. Targeted upper limb vibration may be a viable exercise modality to build muscle efficiently while eliminating some of the barriers associated with exercise for persons with SCI.<br><br>OBJECTIVE: The purpose of this study was to assess preliminary feasibility of completing a single exercise session of upper limb vibration and compare the acute physiological effects to a single session of standard dumbbell resistance exercise.<br><br>METHODS: Individuals with SCI performed seven upper limb exercises (1) isometrically using a vibrating dumbbell at 30 Hz for 60 s (n&#x2009;=&#x2009;22) and (2) using a standard isotonic resistance protocol (n&#x2009;=&#x2009;15).<br><br>RESULTS: Nineteen (86.4%) of 22 participants were able to perform all vibration exercises at 30 Hz but hold time success rates varied from 33% (side flies and front raises) to 95% (internal rotation). No significant differences were found between vibration exercise and standard resistance protocol for blood lactate, power output, and heart rate (P&#x2009;>&#x2009;0.05). Perceptions of the training were positive, with most participants (>70%) expressing interest to train with vibration in the future.<br><br>CONCLUSIONS: Vibration training was not feasible for all participants, suggesting an individualized approach to starting weight and progression may be necessary. Similar acute physiological changes were seen between vibration exercise and standard resistance protocol, suggesting they could have similar benefits. Additional research is needed to determine if vibration exercise is feasible and beneficial to incorporate into a long-term training program.}, }
@article {pmid36109560, year = {2022}, author = {Simpson, CR}, title = {Social Support and Network Formation in a Small-Scale Horticulturalist Population.}, journal = {Scientific data}, volume = {9}, number = {1}, pages = {570}, pmid = {36109560}, issn = {2052-4463}, support = {pf170158//British Academy/ ; }, mesh = {Adult ; Altruism ; Biological Evolution ; Humans ; *Social Networking ; *Social Support ; }, abstract = {Evolutionary studies of cooperation in traditional human societies suggest that helping family and responding in kind when helped are the primary mechanisms for informally distributing resources vital to day-to-day survival (e.g., food, knowledge, money, childcare). However, these studies generally rely on forms of regression analysis that disregard complex interdependences between aid, resulting in the implicit assumption that kinship and reciprocity drive the emergence of entire networks of supportive social bonds. Here I evaluate this assumption using individual-oriented simulations of network formation (i.e., Stochastic Actor-Oriented Models). Specifically, I test standard predictions of cooperation derived from the evolutionary theories of kin selection and reciprocal altruism alongside well-established sociological predictions around the self-organisation of asymmetric relationships. Simulations are calibrated to exceptional public data on genetic relatedness and the provision of tangible aid amongst all 108 adult residents of a village of indigenous horticulturalists in Nicaragua (11,556 ordered dyads). Results indicate that relatedness and reciprocity are markedly less important to whom one helps compared to the supra-dyadic arrangement of the tangible aid network itself.}, }
@article {pmid36097350, year = {2022}, author = {Cenzer, M and M'Gonigle, LK}, title = {Co-evolution of dormancy and dispersal in spatially autocorrelated landscapes.}, journal = {Evolution; international journal of organic evolution}, volume = {76}, number = {11}, pages = {2769-2777}, pmid = {36097350}, issn = {1558-5646}, mesh = {*Biological Evolution ; Spatial Analysis ; }, abstract = {The evolution of dispersal can be driven by spatial processes, such as landscape structure, and temporal processes, such as disturbance. Dormancy, or dispersal in time, is generally thought to evolve in response to temporal processes. In spite of broad empirical and theoretical evidence of trade-offs between dispersal and dormancy, we lack evidence that spatial structure can drive the evolution of dormancy. Here, we develop a simulation-based model of the joint evolution of dispersal and dormancy in spatially heterogeneous landscapes. We show that dormancy and dispersal are each favored under different landscape conditions, but not simultaneously under any of the conditions we tested. We further show that, when dispersal distances are short, dormancy can evolve directly in response to landscape structure. In this case, selection is primarily driven by benefits associated with avoiding kin competition. Our results are similar in both highly simplified and realistically complex landscapes.}, }
@article {pmid36071078, year = {2022}, author = {Ibrahim, AM}, title = {The conditional defector strategies can violate the most crucial supporting mechanisms of cooperation.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {15157}, pmid = {36071078}, issn = {2045-2322}, abstract = {Cooperation is essential for all domains of life. Yet, ironically, it is intrinsically vulnerable to exploitation by cheats. Hence, an explanatory necessity spurs many evolutionary biologists to search for mechanisms that could support cooperation. In general, cooperation can emerge and be maintained when cooperators are sufficiently interacting with themselves. This communication provides a kind of assortment and reciprocity. The most crucial and common mechanisms to achieve that task are kin selection, spatial structure, and enforcement (punishment). Here, we used agent-based simulation models to investigate these pivotal mechanisms against conditional defector strategies. We concluded that the latter could easily violate the former and take over the population. This surprising outcome may urge us to rethink the evolution of cooperation, as it illustrates that maintaining cooperation may be more difficult than previously thought. Moreover, empirical applications may support these theoretical findings, such as invading the cooperator population of pathogens by genetically engineered conditional defectors, which could be a potential therapy for many incurable diseases.}, }
@article {pmid36061780, year = {2022}, author = {Fan, Y and Zhang, R and Zhang, Y and Yue, M}, title = {The effects of genetic distance, nutrient conditions, and recognition ways on outcomes of kin recognition in Glechoma longituba.}, journal = {Frontiers in plant science}, volume = {13}, number = {}, pages = {950758}, pmid = {36061780}, issn = {1664-462X}, abstract = {Kin recognition might help plants decrease competitive cost and improve inclusive fitness with close genes; thus it might interact with environmental factors to affect communities. Whether and how various factors, such as the genetic distance of neighbors, environmental stressors, or the way a plant recognizes its neighbors, might modify plant growth strategies remains unclear. To answer these questions, we conducted experiments in which ramets of a clonal plant, Glechoma longituba, were grown adjacent to different genetically related neighbors (clone kin / close kin / distant kin) in different nutrient conditions (high / medium / low), or with only root exudates from pre-treatment in culture solution. By comparing competitive traits, we found that: (1) kin recognition in G. longituba was enhanced with closer genetic distance; (2) the outcomes of kin recognition were influenced by the extent of nutrient shortage; (3) kin recognition helped to alleviate the nutrient shortage effect; (4) kin recognition via root exudates affected only below-ground growth. Our results provide new insights on the potential for manipulating the outcome of kin recognition by altering neighbor genetic distance, nutrient conditions and recognition ways. Moreover, kin recognition can help plants mitigate the effects of nutrient shortage, with potential implications in agricultural research.}, }
@article {pmid36051883, year = {2022}, author = {Li, H and Tan, Y and Zhang, D}, title = {Genomic discovery and structural dissection of a novel type of polymorphic toxin system in gram-positive bacteria.}, journal = {Computational and structural biotechnology journal}, volume = {20}, number = {}, pages = {4517-4531}, pmid = {36051883}, issn = {2001-0370}, abstract = {Bacteria have developed several molecular conflict systems to facilitate kin recognition and non-kin competition to gain advantages in the acquisition of growth niches and of limited resources. One such example is a large class of so-called polymorphic toxin systems (PTSs), which comprise a variety of the toxin proteins secreted via T2SS, T5SS, T6SS, T7SS and many others. These systems are highly divergent in terms of sequence/structure, domain architecture, toxin-immunity association, and organization of the toxin loci, which makes it difficult to identify and characterize novel systems using traditional experimental and bioinformatic strategies. In recent years, we have been developing and utilizing unique genome-mining strategies and pipelines, based on the organizational principles of both domain architectures and genomic loci of PTSs, for an effective and comprehensive discovery of novel PTSs, dissection of their components, and prediction of their structures and functions. In this study, we present our systematic discovery of a new type of PTS (S8-PTS) in several gram-positive bacteria. We show that the S8-PTS contains three components: a peptidase of the S8 family (subtilases), a polymorphic toxin, and an immunity protein. We delineated the typical organization of these polymorphic toxins, in which a N-terminal signal peptide is followed by a potential receptor binding domain, BetaH, and one of 16 toxin domains. We classified each toxin domain by the distinct superfamily to which it belongs, identifying nine BECR ribonucleases, one Restriction Endonuclease, one HNH nuclease, two novel toxin domains homologous to the VOC enzymes, one toxin domain with the Frataxin-like fold, and several other unique toxin families such as Ntox33 and HicA. Accordingly, we identified 20 immunity families and classified them into different classes of folds. Further, we show that the S8-PTS-associated peptidases are analogous to many other processing peptidases found in T5SS, T7SS, T9SS, and many proprotein-processing peptidases, indicating that they function to release the toxin domains during secretion. The S8-PTSs are mostly found in animal and plant-associated bacteria, including many pathogens. We propose S8-PTSs will facilitate the competition of these bacteria with other microbes or contribute to the pathogen-host interactions.}, }
@article {pmid36033028, year = {2022}, author = {Salem, AAMS and Abdelsattar, M and Abu Al-Diyar, M and Al-Hwailah, AH and Derar, E and Al-Hamdan, NAH and Tilwani, SA}, title = {Altruistic behaviors and cooperation among gifted adolescents.}, journal = {Frontiers in psychology}, volume = {13}, number = {}, pages = {945766}, pmid = {36033028}, issn = {1664-1078}, abstract = {The present study is a differential study that describes the nature of the relationship between cooperation and altruistic behavior in a sample of gifted adolescents in three universities in Egypt and Kuwait University. It also identified the differences between males/females, and senior students/junior students in both cooperation and altruism. A total of 237 gifted adolescents-with average age 21.3 ± SD 2.6 years-from three Egyptian universities: Alexandria University, Sadat Academy for Management Sciences, and Suez University (in Egypt), and Kuwait University, were involved in this study. Measures used in the study include the Scales for Rating the Behavioral Characteristics of Superior Students (SRBCSS), Generative Altruism Scale (GAlS), and The Cooperative/Competitive Strategy Scale (CCSS). Results revealed that there is a significant positive relationship between altruism and cooperation among gifted adolescents. Also, findings show that there are statistically significant differences between males and females in both altruism and cooperation. In addition, there are differences statistically significant between senior students and junior students in both altruism and cooperation in favor of senior students. It is recommended that altruism and cooperation intervention-based programs should be designed to increase the adaptive behaviors of adolescents.}, }
@article {pmid35999250, year = {2022}, author = {Helle, S and Tanskanen, AO and Pettay, JE and Danielsbacka, M}, title = {The interplay of grandparental investment according to the survival status of other grandparent types.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {14390}, pmid = {35999250}, issn = {2045-2322}, mesh = {Adolescent ; Bayes Theorem ; Child ; Child Health ; *Grandparents ; Humans ; Intergenerational Relations ; Surveys and Questionnaires ; }, abstract = {Inclusive fitness theory predicts that grandparental investment in grandchildren aims to maximise their inclusive fitness. Owing to an increasing overlap between successive generations in modern affluent populations, the importance of grandparental investment remains high. Despite the growing literature, there is limited knowledge regarding how the survival status of different grandparent types influences each other's investment in grandchildren. This question was studied by using the Involved Grandparenting and Child Well-Being Survey, which provided nationally representative data of English and Welsh adolescents aged 11-16-years. We applied Bayesian structural equation modeling (BSEM) where grandparental investment in grandchildren was modelled using multi-indicator unobserved latent variable. Our results showed that maternal grandmothers' investment was increased by having a living maternal grandfather but not vice versa. Having a living maternal grandmother was also associated with decreased investment of paternal grandparents while the opposite was not found. These findings indicate that the association between the survival status of other grandparents and the focal grandparents' investment varies between grandparent types.}, }
@article {pmid35984547, year = {2022}, author = {Grof-Tisza, P and Kruizenga, N and Tervahauta, AI and Blande, JD}, title = {Volatile-Mediated Induced and Passively Acquired Resistance in Sagebrush (Artemisia tridentata).}, journal = {Journal of chemical ecology}, volume = {48}, number = {9-10}, pages = {730-745}, pmid = {35984547}, issn = {1573-1561}, support = {797898//HORIZON EUROPE Marie Sklodowska-Curie Actions/ ; 309425//Academy of Finland/ ; }, mesh = {Humans ; *Artemisia/physiology ; Herbivory/physiology ; *Volatile Organic Compounds/pharmacology/metabolism ; Plants/metabolism ; }, abstract = {Plants produce a diversity of secondary metabolites including volatile organic compounds. Some species show discrete variation in these volatile compounds such that individuals within a population can be grouped into distinct chemotypes. A few studies reported that volatile-mediated induced resistance is more effective between plants belonging to the same chemotype and that chemotypes are heritable. The authors concluded that the ability of plants to differentially respond to cues from related individuals that share the same chemotype is a form of kin recognition. These studies assumed plants were actively responding but did not test the mechanism of resistance. A similar result was possible through the passive adsorption and reemission of repellent or toxic VOCs by plants exposed to damage-induced plant volatiles (DIPVs). Here we conducted exposure experiments with five chemotypes of sagebrush in growth chambers; undamaged receiver plants were exposed to either filtered air or DIPVs from mechanically wounded branches. Receiver plants exposed to DIPVs experienced less herbivore damage, which was correlated with increased expression of genes involved in plant defense as well as increased emission of repellent VOCs. Plants belonging to two of the five chemotypes exhibited stronger resistance when exposed to DIPVs from plants of the same chemotypes compared to when DIPVs were from plants of a different chemotype. Moreover, some plants passively absorbed DIPVs and reemitted them, potentially conferring associational resistance. These findings support previous work demonstrating that sagebrush plants actively responded to alarm cues and that the strength of their response was dependent on the chemotypes of the plants involved. This study provides further support for kin recognition in plants but also identified volatile-mediated associational resistance as a passively acquired additional defense mechanism in sagebrush.}, }
@article {pmid35925423, year = {2022}, author = {Berman, CM}, title = {Monkey business: A girl's once strange dream.}, journal = {Primates; journal of primatology}, volume = {63}, number = {5}, pages = {463-481}, pmid = {35925423}, issn = {1610-7365}, mesh = {Animals ; *Commerce ; Female ; Humans ; Macaca mulatta ; Social Behavior ; *Social Dominance ; }, abstract = {For close to 50 years, my research has focused on social relationships and social structure, particularly in macaques, and has been marked by a gradual broadening of scope. Supported by open-minded parents, I followed a once unconventional path into field primatology largely by ignoring distinct gender-based ideas about appropriate occupations for women that were prevalent when I was a child. Later, as Robert Hinde's PhD advisee, I benefited enormously from his mentoring and from the transformative experience he provided. I began by examining infant social development in free-ranging rhesus monkeys and the integration of infants into the kinship and dominance structures of their groups. I gradually branched out to look at (1) kinship and dominance in additional age classes and macaque species, (2) additional aspects of social structure (reciprocity, agonistic support, tolerance, cooperation, conflict management), (3) mechanisms and organizing principles (e.g., attraction to kin and high rank, intergenerational transmission, demography, reciprocity, social style, time constraints) and (4) evolutionary underpinnings of social relationships and structure (e.g., parental investment, kin selection, socioecology, phylogeny, biological markets). For much of this journey, I have been accompanied by talented PhD students who have enriched my experience and whom I am now proud to call colleagues and friends. It is gratifying to realize that my career choice is no longer considered as unconventional as it once was.}, }
@article {pmid35920026, year = {2022}, author = {Chokechaipaisarn, C and Gardner, A}, title = {Density-dependent dispersal promotes female-biased sex allocation in viscous populations.}, journal = {Biology letters}, volume = {18}, number = {8}, pages = {20220205}, pmid = {35920026}, issn = {1744-957X}, support = {771387/ERC_/European Research Council/International ; }, mesh = {*Biological Evolution ; Female ; Humans ; Population Density ; *Sex Ratio ; Viscosity ; }, abstract = {A surprising result emerging from the theory of sex allocation is that the optimal sex ratio is predicted to be completely independent of the rate of dispersal. This striking invariance result has stimulated a huge amount of theoretical and empirical attention in the social evolution literature. However, this sex-allocation invariant has been derived under the assumption that an individual's dispersal behaviour is not modulated by population density. Here, we investigate how density-dependent dispersal shapes patterns of sex allocation in a viscous-population setting. Specifically, we find that if individuals are able to adjust their dispersal behaviour according to local population density, then they are favoured to do so, and this drives the evolution of female-biased sex allocation. This result obtains because, whereas under density-independent dispersal, population viscosity is associated not only with higher relatedness-which promotes female bias-but also with higher kin competition-which inhibits female bias-under density-dependent dispersal, the kin-competition consequences of a female-biased sex ratio are entirely abolished. We derive analytical results for the full range of group sizes and costs of dispersal, under haploid, diploid and haplodiploid modes of inheritance. These results show that population viscosity promotes female-biased sex ratios in the context of density-dependent dispersal.}, }
@article {pmid35902334, year = {2022}, author = {Hitchcock, TJ and Gardner, A}, title = {Paternal genome elimination promotes altruism in viscous populations.}, journal = {Evolution; international journal of organic evolution}, volume = {76}, number = {9}, pages = {2191-2198}, pmid = {35902334}, issn = {1558-5646}, mesh = {Female ; Male ; *Altruism ; *Biological Evolution ; Haploidy ; Viscosity ; Animals ; }, abstract = {Population viscosity has long been thought to promote the evolution of altruism. However, in the simplest scenarios, the potential for altruism is invariant with respect to dispersal-a surprising result that holds for haploidy, diploidy, and haplodiploidy (arrhenotoky). Here, we develop a kin-selection model to investigate how population viscosity affects the potential for altruism in species with male paternal genome elimination (PGE), exploring altruism enacted by both females and males, and both juveniles and adults. We find that (1) PGE promotes altruistic behaviors relative to the other inheritance systems, and to a degree that depends on the extent of paternal genome expression. (2) Under PGE, dispersal increases the potential for altruism in juveniles and decreases it in adults. (3) The genetics of PGE can lead to striking differences in sex-specific potentials for altruism, even in the absence of any sex differences in ecology.}, }
@article {pmid35782010, year = {2022}, author = {Fréville, H and Montazeaud, G and Forst, E and David, J and Papa, R and Tenaillon, MI}, title = {Shift in beneficial interactions during crop evolution.}, journal = {Evolutionary applications}, volume = {15}, number = {6}, pages = {905-918}, pmid = {35782010}, issn = {1752-4571}, abstract = {Plant domestication can be viewed as a form of co-evolved interspecific mutualism between humans and crops for the benefit of the two partners. Here, we ask how this plant-human mutualism has, in turn, impacted beneficial interactions within crop species, between crop species, and between crops and their associated microbial partners. We focus on beneficial interactions resulting from three main mechanisms that can be promoted by manipulating genetic diversity in agrosystems: niche partitioning, facilitation, and kin selection. We show that a combination of factors has impacted either directly or indirectly plant-plant interactions during domestication and breeding, with a trend toward reduced benefits arising from niche partitioning and facilitation. Such factors include marked decrease of molecular and functional diversity of crops and other organisms present in the agroecosystem, mass selection, and increased use of chemical inputs. For example, the latter has likely contributed to the relaxation of selection pressures on nutrient-mobilizing traits such as those associated to root exudation and plant nutrient exchanges via microbial partners. In contrast, we show that beneficial interactions arising from kin selection have likely been promoted since the advent of modern breeding. We highlight several issues that need further investigation such as whether crop phenotypic plasticity has evolved and could trigger beneficial interactions in crops, and whether human-mediated selection has impacted cooperation via kin recognition. Finally, we discuss how plant breeding and agricultural practices can help promoting beneficial interactions within and between species in the context of agroecology where the mobilization of diversity and complexity of crop interactions is viewed as a keystone of agroecosystem sustainability.}, }
@article {pmid35730152, year = {2022}, author = {Micheletti, AJC and Ge, E and Zhou, L and Chen, Y and Zhang, H and Du, J and Mace, R}, title = {Religious celibacy brings inclusive fitness benefits.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1977}, pages = {20220965}, pmid = {35730152}, issn = {1471-2954}, mesh = {Child ; China ; *Family ; Genetic Fitness ; Humans ; Male ; Reproduction ; *Sexual Abstinence ; Siblings ; }, abstract = {The influence of inclusive fitness interests on the evolution of human institutions remains unclear. Religious celibacy constitutes an especially puzzling institution, often deemed maladaptive. Here, we present sociodemographic data from an agropastoralist Buddhist population in western China, where parents sometimes sent a son to the monastery. We find that men with a monk brother father more children, and grandparents with a monk son have more grandchildren, suggesting that the practice is adaptive. We develop a model of celibacy to elucidate the inclusive fitness costs and benefits associated with this behaviour. We show that a minority of sons being celibate can be favoured if this increases their brothers' reproductive success, but only if the decision is under parental, rather than individual, control. These conditions apply to monks in our study site. Inclusive fitness considerations appear to play a key role in shaping parental preferences to adopt this cultural practice.}, }
@article {pmid35703047, year = {2022}, author = {Hearn, LR and Davies, OK and Schwarz, MP}, title = {Extreme reproductive skew at the dawn of sociality is consistent with inclusive fitness theory but problematic for routes to eusociality.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1976}, pages = {20220652}, pmid = {35703047}, issn = {1471-2954}, mesh = {Animals ; Bees ; Biological Evolution ; Female ; Humans ; Male ; Pregnancy ; *Reproduction ; *Social Behavior ; Symbiosis ; }, abstract = {To understand the earliest stages of social evolution, we need to identify species that are undergoing the initial steps into sociality. Amphylaeus morosus is the only unambiguously known social species in the bee family Colletidae and represents an independent origin of sociality within the Apoidea. This allows us to investigate the selective factors promoting the transition from solitary to social nesting. Using genome-wide SNP genotyping, we infer robust pedigree relationships to identify maternity of brood and intracolony relatedness for colonies at the end of the reproductive season. We show that A. morosus forms both matrifilial and full-sibling colonies, both involving complete or almost complete monopolization over reproduction. In social colonies, the reproductive primary was also the primary forager with the secondary female remaining in the nest, presumably as a guard. Social nesting provided significant protection against parasitism and increased brood survivorship in general. We show that secondary females gain large indirect fitness benefits from defensive outcomes, enough to satisfy the conditions of inclusive fitness theory, despite an over-production of males in social colonies. These results suggest an avenue to sociality that involves high relatedness and, very surprisingly, extreme reproductive skew in its earliest stages and raises important questions about the evolutionary steps in pathways to eusociality.}, }
@article {pmid35622922, year = {2022}, author = {García-Ruiz, I and Quiñones, A and Taborsky, M}, title = {The evolution of cooperative breeding by direct and indirect fitness effects.}, journal = {Science advances}, volume = {8}, number = {21}, pages = {eabl7853}, pmid = {35622922}, issn = {2375-2548}, abstract = {The evolution of cooperative breeding has been traditionally attributed to the effect of kin selection. While there is increasing empirical evidence that direct fitness benefits are relevant, the relative importance of alternative selection mechanisms is largely obscure. Here, we model the coevolution of the cornerstones of cooperative breeding, delayed dispersal, and alloparental care, across different ecological scenarios while allowing individuals to adjust philopatry and helping levels. Our results suggest that (i) direct fitness benefits from grouping are the main driver for the evolution of philopatry; (ii) kin selection is mainly responsible for the emergence of alloparental care, but group augmentation can be a sufficient promoter in harsh environments; (iii) the coevolution of philopatry and alloparental care is subject to positive feedback; and (iv) age-dependent dispersal is triggered by both group benefits and relatedness. Model predictions are supported by empirical data and provide good opportunities for comparative analyses and experimental tests of causality.}, }
@article {pmid35592877, year = {2022}, author = {Fouilloux, CA and Fromhage, L and Valkonen, JK and Rojas, B}, title = {Size-dependent aggression towards kin in a cannibalistic species.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {33}, number = {3}, pages = {582-591}, pmid = {35592877}, issn = {1045-2249}, abstract = {In juveniles extreme intraspecies aggression can seem counter-intuitive, as it might endanger their developmental goal of surviving until reproductive stage. Ultimately, aggression can be vital for survival, although the factors (e.g., genetic or environmental) leading to the expression and intensity of this behavior vary across taxa. Attacking (and sometimes killing) related individuals may reduce inclusive fitness; as a solution to this problem, some species exhibit kin discrimination and preferentially attack unrelated individuals. Here, we used both experimental and modeling approaches to consider how physical traits (e.g., size in relation to opponent) and genetic relatedness mediate aggression in dyads of cannibalistic Dendrobates tinctorius tadpoles. We paired full-sibling, half-sibling, and non-sibling tadpoles of different sizes together in an arena and recorded their aggression and activity. We found that the interaction between relative size and relatedness predicts aggressive behavior: large individuals in non-sibling dyads are significantly more aggressive than large individuals in sibling dyads. Unexpectedly, although siblings tended to attack less overall, in size-mismatched pairs they attacked faster than in non-sibling treatments. Using a theoretical model to complement these empirical findings, we propose that larval aggression reflects a balance between relatedness and size where individuals trade-off their own fitness with that of their relatives. Lay SummaryBefore you eat someone, you have to attack them first. Here, we investigated the factors that shape aggression in the cannibalistic tadpoles of the dyeing poison frog. We find that aggression depends on both size and relatedness: when set in pairs, large tadpoles are half as aggressive towards their smaller siblings than to nonsibs. It looks like belonging to the same family provides some protection against aggression, though no one is ever truly safe.}, }
@article {pmid35560232, year = {2022}, author = {Roper, M and Sturrock, NJ and Hatchwell, BJ and Green, JP}, title = {Individual variation explains ageing patterns in a cooperatively breeding bird, the long-tailed tit Aegithalos caudatus.}, journal = {The Journal of animal ecology}, volume = {91}, number = {7}, pages = {1521-1534}, pmid = {35560232}, issn = {1365-2656}, support = {NE/I027118/1//Natural Environment Research Council/ ; NE/R001669/1//Natural Environment Research Council/ ; BB/M011224/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {*Aging/physiology ; Animals ; Cooperative Behavior ; Longevity ; Reproduction ; *Songbirds/growth &amp; development ; }, abstract = {Alloparental care in cooperatively breeding species may alter breeder age-specific survival and reproduction and subsequently senescence. The helping behaviour itself might also undergo age-related change, and decisions to help in facultative cooperative breeders are likely to be affected by individual condition. Helpers in long-tailed tits Aegithalos caudatus assist relatives after failing to raise their own brood, with offspring from helped nests being more likely to recruit into the breeding population. Using data collected over 25 years, we examined the age trajectories of survival and reproduction in adult long-tailed tits to determine how these were affected by the presence or absence of helpers and how helper behaviour changed with age. There was evidence for increased reproductive performance with breeder age, but no effect of age on the probability of survival. We found no evidence of significant senescent decline in survival or reproductive performance, although individuals accrued less inclusive fitness in their last year of life. Lifetime reproductive success was positively related to both reproductive life span and body mass. Within a season, breeders that were assisted by helpers enjoyed greater reproductive success through enhanced offspring recruitment in the following year. We found no evidence that age affected an individual's propensity to help, or the amount of indirect fitness accrued through helping. We found a positive correlation between life span and multiple components of reproductive success, suggesting that individual variation in quality underpins age-related variation in fitness in this species. Helping decisions are driven by condition, and lifetime inclusive fitness of immigrants was predicted by body mass. These findings further support individual heterogeneity in quality being a major driver for fitness gains across the life course of long-tailed tits.}, }
@article {pmid35440705, year = {2022}, author = {Tuominen, LS and Helle, S and Helanterä, H and Karell, P and Rapeli, L and Richmond, D and Vuorisalo, T and Brommer, JE}, title = {Structural equation modeling reveals decoupling of ecological and self-perceived outcomes in a garden box social-ecological system.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {6425}, pmid = {35440705}, issn = {2045-2322}, mesh = {Ecosystem ; *Gardening ; *Gardens ; Latent Class Analysis ; Social Environment ; }, abstract = {It is well known that green urban commons enhance mental and physical well-being and improve local biodiversity. We aim to investigate how these outcomes are related in an urban system and which variables are associated with better outcomes. We model the outcomes of an urban common-box gardening-by applying the Social-Ecological Systems (SES) framework. We expand the SES framework by analyzing it from the perspective of social evolution theory. The system was studied empirically through field inventories and questionnaires and modeled quantitatively by Structural Equation Modeling (SEM). This method offers powerful statistical models of complex social-ecological systems. Our results show that objectively evaluated ecological outcomes and self-perceived outcomes are decoupled: gardening groups that successfully govern the natural resource ecologically do not necessarily report many social, ecological, or individual benefits, and vice versa. Social capital, box location, gardener concerns, and starting year influenced the changes in the outcomes. In addition, the positive association of frequent interactions with higher self-perceived outcomes, and lack of such association with relatedness of group members suggests that reciprocity rather than kin selection explains cooperation. Our findings exemplify the importance of understanding natural resource systems at a very low "grassroot" level.}, }
@article {pmid35432938, year = {2022}, author = {Marquez-Rosado, A and Garcia-Co, C and Londoño-Nieto, C and Carazo, P}, title = {No evidence that relatedness or familiarity modulates male harm in Drosophila melanogaster flies from a wild population.}, journal = {Ecology and evolution}, volume = {12}, number = {4}, pages = {e8803}, pmid = {35432938}, issn = {2045-7758}, abstract = {Sexual selection frequently promotes the evolution of aggressive behaviors that help males compete against their rivals, but which may harm females and hamper their fitness. Kin selection theory predicts that optimal male-male competition levels can be reduced when competitors are more genetically related to each other than to the population average, contributing to resolve this sexual conflict. Work in Drosophila melanogaster has spearheaded empirical tests of this idea, but studies so far have been conducted in laboratory-adapted populations in homogeneous rearing environments that may hamper kin recognition, and used highly skewed sex ratios that may fail to reflect average natural conditions. Here, we performed a fully factorial design with the aim of exploring how rearing environment (i.e., familiarity) and relatedness affect male-male aggression, male harassment, and overall male harm levels in flies from a wild population of Drosophila melanogaster, under more natural conditions. Namely, we (a) manipulated relatedness and familiarity so that larvae reared apart were raised in different environments, as is common in the wild, and (b) studied the effects of relatedness and familiarity under average levels of male-male competition in the field. We show that, contrary to previous findings, groups of unrelated-unfamiliar males were as likely to fight with each other and harass females than related-familiar males and that overall levels of male harm to females were similar across treatments. Our results suggest that the role of kin selection in modulating sexual conflict is yet unclear in Drosophila melanogaster, and call for further studies that focus on natural populations and realistic socio-sexual and ecological environments.}, }
@article {pmid35429546, year = {2022}, author = {Taylor, JH and Grieb, ZA}, title = {Species differences in the effect of oxytocin on maternal behavior: A model incorporating the potential for allomaternal contributions.}, journal = {Frontiers in neuroendocrinology}, volume = {65}, number = {}, pages = {100996}, doi = {10.1016/j.yfrne.2022.100996}, pmid = {35429546}, issn = {1095-6808}, mesh = {Animals ; Female ; Humans ; Mammals ; *Maternal Behavior ; Mothers ; *Oxytocin ; Receptors, Oxytocin ; Species Specificity ; }, abstract = {Oxytocin has historically been linked to processes involved with maternal behavior. However, the relative importance of oxytocin for maternal behavior widely varies among mammalian species, from indispensable to apparently nonessential. This review proposes a new model in which the relative importance of oxytocin for mothering across species is explained by an evolutionary pressure which we term "allomaternal potential", or the degree to which other conspecifics are capable and likely to assist with caregiving. It is notable that in animals where allomaternal potential is high (i.e., many quality helpers are available), oxytocin is decoupled from mothering. However, in animals where allomaternal potential is low (i.e., conspecifics refuse to, or do not provide, quality help), oxytocin is crucial for mothering. We posit that this relationship is a form of kin selection, whereby oxytocin is a signal that leads mothers to preferentially dispense resources to their own young when quality helpers are unlikely.}, }
@article {pmid35412899, year = {2022}, author = {Levy, M and Lo, AW}, title = {Hamilton's rule in economic decision-making.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, number = {16}, pages = {e2108590119}, pmid = {35412899}, issn = {1091-6490}, mesh = {*Altruism ; *Biological Evolution ; Decision Making ; Economics, Behavioral ; Humans ; *Selection, Genetic ; }, abstract = {Hamilton’s rule [W. D. Hamilton, Am. Nat. 97, 354–356 (1963); W. D. Hamilton, J. Theor. Biol. 7, 17–52 (1964)] quantifies the central evolutionary ideas of inclusive fitness and kin selection into a simple algebraic relationship. Evidence consistent with Hamilton’s rule is found in many animal species. A drawback of investigating Hamilton’s rule in these species is that one can estimate whether a given behavior is consistent with the rule, but a direct examination of the exact cutoff for altruistic behavior predicted by Hamilton is almost impossible. However, to the degree that economic resources confer survival benefits in modern society, Hamilton’s rule may be applicable to economic decision-making, in which case techniques from experimental economics offer a way to determine this cutoff. We employ these techniques to examine whether Hamilton’s rule holds in human decision-making, by measuring the dependence between an experimental subject’s maximal willingness to pay for a gift of $50 to be given to someone else and the genetic relatedness of the subject to the gift’s recipient. We find good agreement with the predictions of Hamilton’s rule. Moreover, regression analysis of the willingness to pay versus genetic relatedness, the number of years living in the same residence, age, and sex shows that almost all the variation is explained by genetic relatedness. Similar but weaker results are obtained from hypothetical questions regarding the maximal risk to her own life that the subject is willing to take in order to save the recipient’s life.}, }
@article {pmid35398139, year = {2022}, author = {Straub, L and Strobl, V and Bruckner, S and Camenzind, DW and Van Oystaeyen, A and Wäckers, F and Williams, GR and Neumann, P}, title = {Buffered fitness components: Antagonism between malnutrition and an insecticide in bumble bees.}, journal = {The Science of the total environment}, volume = {833}, number = {}, pages = {155098}, doi = {10.1016/j.scitotenv.2022.155098}, pmid = {35398139}, issn = {1879-1026}, mesh = {Animals ; Bees ; Insecta ; *Insecticides/toxicity ; Male ; *Malnutrition ; Reproduction ; Spermatozoa ; }, abstract = {Global insect biodiversity declines due to reduced fitness are linked to interactions between environmental stressors. In social insects, inclusive fitness depends on successful mating of reproductives, i.e. males and queens, and efficient collaborative brood care by workers. Therefore, interactive effects between malnutrition and environmental pollution on sperm and feeding glands (hypopharyngeal glands (HPGs)) would provide mechanisms for population declines, unless buffered against due to their fitness relevance. However, while negative effects for bumble bee colony fitness are known, the effects of malnutrition and insecticide exposure singly and in combination on individuals are poorly understood. Here we show, in a fully-crossed laboratory experiment, that malnutrition and insecticide exposure result in neutral or antagonistic interactions for spermatozoa and HPGs of bumble bees, Bombus terrestris, suggesting strong selection to buffer key colony fitness components. No significant effects were observed for mortality and consumption, but significant negative effects were revealed for spermatozoa traits and HPGs. The combined effects on these parameters were not higher than the individual stressor effects, which indicates an antagonistic interaction between both. Despite the clear potential for additive effects, due to the individual stressors impairing muscle quality and neurological control, simultaneous malnutrition and insecticide exposure surprisingly did not reveal an increased impact compared to individual stressors, probably due to key fitness traits being resilient. Our data support that stressor interactions require empirical tests on a case-by-case basis and need to be regarded in context to understand underlying mechanisms and so adequately mitigate the ongoing decline of the entomofauna.}, }
@article {pmid35369745, year = {2022}, author = {Mullon, C and Lehmann, L}, title = {Evolution of warfare by resource raiding favours polymorphism in belligerence and bravery.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {377}, number = {1851}, pages = {20210136}, pmid = {35369745}, issn = {1471-2970}, mesh = {Aggression ; Animals ; *Courage ; Phenotype ; Polymorphism, Genetic ; Warfare ; }, abstract = {From protists to primates, intergroup aggression and warfare over resources have been observed in several taxa whose populations typically consist of groups connected by limited genetic mixing. Here, we model the coevolution between four traits relevant to this setting: (i) investment into common-pool resource production within groups (helping); (ii) proclivity to raid other groups to appropriate their resources (belligerence); and investments into (iii) defense and (iv) offense of group contests (defensive and offensive bravery). We show that when traits coevolve, the population often experiences disruptive selection favouring two morphs: 'Hawks', who express high levels of both belligerence and offensive bravery; and 'Doves', who express neither. This social polymorphism involves further among-traits associations when the fitness costs of helping and bravery interact. In particular, if helping is antagonistic with both forms of bravery, coevolution leads to the coexistence of individuals that either: (i) do not participate into common-pool resource production but only in its defense and appropriation (Scrounger Hawks) or (ii) only invest into common pool resource production (Producer Doves). Provided groups are not randomly mixed, these findings are robust to several modelling assumptions. This suggests that inter-group aggression is a potent mechanism in favouring within-group social diversity and behavioural syndromes. This article is part of the theme issue 'Intergroup conflict across taxa'.}, }
@article {pmid35369743, year = {2022}, author = {Rodrigues, AMM and Barker, JL and Robinson, EJH}, title = {From inter-group conflict to inter-group cooperation: insights from social insects.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {377}, number = {1851}, pages = {20210466}, pmid = {35369743}, issn = {1471-2970}, mesh = {Aggression ; Animals ; *Group Processes ; Humans ; *Insecta ; }, abstract = {The conflict between social groups is widespread, often imposing significant costs across multiple groups. The social insects make an ideal system for investigating inter-group relationships, because their interaction types span the full harming-helping continuum, from aggressive conflict, to mutual tolerance, to cooperation between spatially separate groups. Here we review inter-group conflict in the social insects and the various means by which they reduce the costs of conflict, including individual or colony-level avoidance, ritualistic behaviours and even group fusion. At the opposite extreme of the harming-helping continuum, social insect groups may peacefully exchange resources and thus cooperate between groups in a manner rare outside human societies. We discuss the role of population viscosity in favouring inter-group cooperation. We present a model encompassing intra- and inter-group interactions, and local and long-distance dispersal. We show that in this multi-level population structure, the increased likelihood of cooperative partners being kin is balanced by increased kin competition, such that neither cooperation (helping) nor conflict (harming) is favoured. This model provides a baseline context in which other intra- and inter-group processes act, tipping the balance toward or away from conflict. We discuss future directions for research into the ecological factors shaping the evolution of inter-group interactions. This article is part of the theme issue 'Intergroup conflict across taxa'.}, }
@article {pmid35356586, year = {2022}, author = {Scheiner, SM and Barfield, M and Holt, RD}, title = {The factors that favor adaptive habitat construction versus non-adaptive environmental conditioning.}, journal = {Ecology and evolution}, volume = {12}, number = {3}, pages = {e8763}, pmid = {35356586}, issn = {2045-7758}, abstract = {Adaptive habitat construction is a process by which individuals alter their environment so as to increase their (inclusive) fitness. Such alterations are a subset of the myriad ways that individuals condition their environment. We present an individual-based model of habitat construction to explore what factors might favor selection when the benefits of environmental alterations are shared by individuals of the same species. Our results confirm the predictions of inclusive fitness and group selection theory and expectations based on previous models that construction will be more favored when its benefits are more likely to be directed to self or near kin. We found that temporal variation had no effect on the evolution of construction. For spatial heterogeneity, construction was disfavored when the spatial pattern of movement did not match the spatial pattern of environmental heterogeneity, especially when there was spatial heterogeneity in the optimal amount of construction. Under those conditions, very strong selection was necessary to favor genetic differentiation of construction propensity among demes. We put forth a constitutive theory for the evolution of adaptive habitat construction that unifies our model with previous verbal and quantitative models into a formal conceptual framework.}, }
@article {pmid35323522, year = {2022}, author = {Radford, JM and Chen, D and Chernyshova, AM and Taylor, C and Guoth, AW and Wu, T and Hill, KA and Thompson, GJ}, title = {Differential Selection on Caste-Associated Genes in a Subterranean Termite.}, journal = {Insects}, volume = {13}, number = {3}, pages = {}, pmid = {35323522}, issn = {2075-4450}, support = {RGPIN-2020-05647//Natural Sciences and Engineering Research Council/ ; }, abstract = {Analyzing the information-rich content of RNA can help uncover genetic events associated with social insect castes or other social polymorphisms. Here, we exploit a series of cDNA libraries previously derived from whole-body tissue of different castes as well as from three behaviourally distinct populations of the Eastern subterranean termite Reticulitermes flavipes. We found that the number (~0.5 M) of single nucleotide variants (SNVs) was roughly equal between nymph, worker and soldier caste libraries, but dN/dS (ratio of nonsynonymous to synonymous substitutions) analysis suggested that some of these variants confer a caste-specific advantage. Specifically, the dN/dS ratio was high (~4.3) for genes expressed in the defensively specialized soldier caste, relative to genes expressed by other castes (~1.7−1.8) and regardless of the North American population (Toronto, Raleigh, Boston) from which the castes were sampled. The populations, meanwhile, did show a large difference in SNV count but not in the manner expected from known demographic and behavioural differences; the highly invasive unicolonial population from Toronto was not the least diverse and did not show any other unique substitution patterns, suggesting any past bottleneck associated with invasion or with current unicoloniality has become obscured at the RNA level. Our study raises two important hypotheses relevant to termite sociobiology. First, the positive selection (dN/dS > 1) inferred for soldier-biased genes is presumably indirect and of the type mediated through kin selection, and second, the behavioural changes that accompany some social insect urban invasions (i.e., ‘unicoloniality’) may be detached from the loss-of-diversity expected from invasion bottlenecks.}, }
@article {pmid35259982, year = {2022}, author = {Kanwal, J and Gardner, A}, title = {Population viscosity promotes altruism under density-dependent dispersal.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1970}, pages = {20212668}, pmid = {35259982}, issn = {1471-2954}, mesh = {*Altruism ; *Biological Evolution ; Female ; Humans ; Parturition ; Population Dynamics ; Pregnancy ; Selection, Genetic ; Viscosity ; }, abstract = {A basic mechanism of kin selection is population viscosity, whereby individuals do not move far from their place of birth and hence tend to be surrounded by relatives. In such circumstances, even indiscriminate altruism among neighbours will often involve interactions between kin, which has a promoting effect on the evolution of altruism. This has the potential to explain altruistic behaviour across the whole tree of life, including in taxa for which recognition of kin is implausible. However, population viscosity may also intensify resource competition among kin, which has an inhibitory effect on altruism. Indeed, in the simplest scenario, in which individuals disperse with a fixed probability, these two effects have been shown to exactly cancel such that there is no net impact of viscosity on altruism. Here, we show that if individuals are able to disperse conditionally upon local density, they are favoured to do so, with more altruistic neighbourhoods exhibiting a higher rate of dispersal and concomitant relaxation of kin competition. Comparing across different populations or species, this leads to a negative correlation between overall levels of dispersal and altruism. We demonstrate both analytically and using individual-based simulations that population viscosity promotes the evolution of altruism under density-dependent dispersal.}, }
@article {pmid35253258, year = {2022}, author = {Lerdau, M}, title = {The complicated legacy of E. O. Wilson with respect to genetics and human behavior.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {44}, number = {5}, pages = {e2200034}, doi = {10.1002/bies.202200034}, pmid = {35253258}, issn = {1521-1878}, mesh = {*Behavior ; Humans ; *Selection, Genetic ; }, abstract = {Over the arc of his career, E. O. Wilson first embraced, then popularized, and finally rejected an extreme genetical hereditarian view of human nature. The controversy that ensued during the period of popularization (largely in the 1970s and 1980s) obscured the fact that empirical and theoretical research during this time undercut the assumptions necessary for this view. By the end of his career, Wilson accepted the fact that individual/kin selection models were insufficient to explain human behavior and society, and he began conducting research based upon multilevel (group) selection, an idea he had previously scorned.}, }
@article {pmid35222785, year = {2022}, author = {Maley, CC and Seyedi, S}, title = {The life history theory of the Lord of the Rings: a randomized controlled trial of using fact versus fiction to teach life history theory.}, journal = {Evolution}, volume = {15}, number = {1}, pages = {2}, pmid = {35222785}, issn = {1936-6426}, support = {U54 CA217376/CA/NCI NIH HHS/United States ; R01 CA185138/CA/NCI NIH HHS/United States ; P01 CA091955/CA/NCI NIH HHS/United States ; R01 CA170595/CA/NCI NIH HHS/United States ; R01 CA140657/CA/NCI NIH HHS/United States ; }, abstract = {UNLABELLED: Does asking students to apply concepts from evolution to a fictional context, compared to a novel biological context, improve their understanding, exam performance or enjoyment of the material? Or does it harm their education by taking time away from true biology? At our institution, we sometimes ask students to apply life history theory to species from fictional movies, television shows or books. Previously, we had used a factual article on life history theory, to supplement our textbook. We wrote an alternative introduction to life history theory (included in the additional files for educational use), using Tolkien's fictional species from his Lord of the Rings books. We also introduce the biological species definition, sexual selection, sexual dimorphism, kin selection, and the handicap principle, as those concepts arose naturally in the discussion of the fictional species. Life history theory predicts strong correlations between traits affecting reproduction, growth and survival, which are all shaped by the ecology of the species. Thus, we can teach life history theory by asking students to infer traits and aspects of the ecology of a fictional species that have never been described, based on the partial information included in the fictional sources. In a large, third year undergraduate evolution course at Arizona State University, we randomized 16 tutorial sections of a total of 264 students to either read our article on the life history theory of Lord of the Rings, or the factual article we had used previously in the course. We found that the exam performance on life history questions for the two groups were almost identical, except that fans of The Lord of the Rings who had read our article did better on the exam. Enjoyment, engagement and interest in life history theory was approximately a full point higher on a 5-point Likert scale for the students that had read the fictional article, and was highly statistically significantly different (T-test p < 0.001 for all questions). There was no difference between the two groups in their familiarity or enjoyment of The Lord of the Rings stories themselves. Reading the article that taught life history theory by applying it to the species of The Lord of the Rings neither helped nor harmed exam performance, but did significantly improve student enjoyment, engagement and interest in life history theory, and even improved exam scores in students who liked The Lord of the Rings. Using fiction to teach science may also help to engage non-traditional students, such as world-builders, outside of our institutions of education. By encouraging students to apply the scientific ideas to their favorite stories from their own cultures, we may be able to improve both inclusivity and education.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12052-022-00160-8.}, }
@article {pmid35196086, year = {2022}, author = {Shah, SS and Rubenstein, DR}, title = {Prenatal environmental conditions underlie alternative reproductive tactics that drive the formation of a mixed-kin cooperative society.}, journal = {Science advances}, volume = {8}, number = {8}, pages = {eabk2220}, pmid = {35196086}, issn = {2375-2548}, abstract = {Although animal societies often evolve due to limited natal dispersal that results in kin clustering and facilitates cooperation among relatives, many species form cooperative groups with low kin structure. These groups often comprise residents and immigrants of the same sex that compete for breeding opportunities. To understand how these mixed-kin societies form, we investigated the causes and fitness consequences of dispersal decisions in male cooperatively breeding superb starlings (Lamprotornis superbus) inhabiting a climatically unpredictable environment. We show that the two alternative reproductive tactics-natal dispersal or philopatry-exhibit reproductive trade-offs resulting in equivalent lifetime inclusive fitness. Unexpectedly, an individual's tactic is related to the prenatal environment its parents experience before laying rather than the environment it experiences as a juvenile. Individuals that adopt the tactic not predicted by prenatal environmental conditions have lower fitness. Ultimately, climate-driven oscillating selection appears to stabilize mixed-kin societies despite the potential for social conflict.}, }
@article {pmid35193981, year = {2022}, author = {Belcher, LJ and Dewar, AE and Ghoul, M and West, SA}, title = {Kin selection for cooperation in natural bacterial populations.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, number = {9}, pages = {}, pmid = {35193981}, issn = {1091-6490}, support = {834164/ERC_/European Research Council/International ; }, mesh = {*Bacterial Physiological Phenomena ; Genes, Bacterial ; Mutation ; Pseudomonas aeruginosa/genetics ; Quorum Sensing ; }, abstract = {Bacteria produce a range of molecules that are secreted from the cell and can provide a benefit to the local population of cells. Laboratory experiments have suggested that these "public goods" molecules represent a form of cooperation, favored because they benefit closely related cells (kin selection). However, there is a relative lack of data demonstrating kin selection for cooperation in natural populations of bacteria. We used molecular population genetics to test for signatures of kin selection at the genomic level in natural populations of the opportunistic pathogen Pseudomonas aeruginosa We found consistent evidence from multiple traits that genes controlling putatively cooperative traits have higher polymorphism and greater divergence and are more likely to harbor deleterious mutations relative to genes controlling putatively private traits, which are expressed at similar rates. These patterns suggest that cooperative traits are controlled by kin selection, and we estimate that the relatedness for social interactions in P. aeruginosa is r = 0.84. More generally, our results demonstrate how molecular population genetics can be used to study the evolution of cooperation in natural populations.}, }
@article {pmid35168400, year = {2022}, author = {Helle, S and Tanskanen, AO and Coall, DA and Danielsbacka, M}, title = {Matrilateral bias of grandparental investment in grandchildren persists despite the grandchildren's adverse early life experiences.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1969}, pages = {20212574}, pmid = {35168400}, issn = {1471-2954}, mesh = {Adolescent ; Bias ; Biological Evolution ; Child ; Family ; *Grandparents ; Humans ; Intergenerational Relations ; Reproduction ; }, abstract = {Evolutionary theory predicts a downward flow of investment from older to younger generations, representing individual efforts to maximize inclusive fitness. Maternal grandparents and maternal grandmothers (MGMs) in particular consistently show the highest levels of investment (e.g. time, care and resources) in their grandchildren. Grandparental investment overall may depend on social and environmental conditions that affect the development of children and modify the benefits and costs of investment. Currently, the responses of grandparents to adverse early life experiences (AELEs) in their grandchildren are assessed from a perspective of increased investment to meet increased need. Here, we formulate an alternative prediction that AELEs may be associated with reduced grandparental investment, as they can reduce the reproductive value of the grandchildren. Moreover, we predicted that paternal grandparents react more strongly to AELEs compared to maternal grandparents because maternal kin should expend extra effort to invest in their descendants. Using population-based survey data for English and Welsh adolescents, we found evidence that the investment of maternal grandparents (MGMs in particular) in their grandchildren was unrelated to the grandchildren's AELEs, while paternal grandparents invested less in grandchildren who had experienced more AELEs. These findings seemed robust to measurement errors in AELEs and confounding due to omitted shared causes.}, }
@article {pmid35154777, year = {2022}, author = {Fox, M and Wiley, KS}, title = {How a pregnant woman's relationships with her siblings relate to her mental health: a prenatal allocare perspective.}, journal = {Evolution, medicine, and public health}, volume = {10}, number = {1}, pages = {1-20}, pmid = {35154777}, issn = {2050-6201}, support = {F32 MD015201/MD/NIMHD NIH HHS/United States ; K01 DK105110/DK/NIDDK NIH HHS/United States ; P2C HD041022/HD/NICHD NIH HHS/United States ; R03 DK125524/DK/NIDDK NIH HHS/United States ; }, abstract = {BACKGROUND: In cooperatively breeding species, individuals may promote their inclusive fitness through allomothering. Humans exhibit some features of cooperative breeding, and previous studies have focused on allomothering by grandparents and juvenile siblings in the postnatal period. We hypothesize that a pregnant woman's relationships with her siblings (offspring's maternal aunts and uncles) are beneficial for maternal affect in ways that can enhance the siblings' inclusive fitness. Maternal affect during pregnancy is a salient target of allocare given the detrimental effects of antepartum mood disorders on birth and infant outcomes.<br><br>METHODOLOGY: We test our hypotheses in a cohort of pregnant Latina women in Southern California (N = 201). Predictor variables of interest include number of siblings a participant has, if she has sisters, frequency of seeing siblings, and frequency of communication with siblings. Outcome variables measuring maternal affect include depression, state anxiety, pregnancy-related anxiety and perceived stress.<br><br>RESULTS: Having at least one sister and greater frequency of communication with siblings were associated with fewer depressive symptoms during pregnancy. No significant associations were found between sibling variables and other measures of affect.<br><br>CONCLUSION AND IMPLICATIONS: Results suggest that how frequently you communicate with, and not how often you see, siblings could be protective against risk of antepartum depression. Sibling allomothering could impart effects through social-emotional support rather than instrumental support, as a strategy to benefit the prenatal environment in which future nieces and nephews develop. Allomothering may be particularly important in cultural contexts that value family relationships. Future studies should investigate other communities.}, }
@article {pmid35063725, year = {2022}, author = {Roth, JD and Dobson, FS and Neuhaus, P and Abebe, A and Barra, T and Boonstra, R and Edwards, PD and Gonzalez, MA and Hammer, TL and Harscouet, E and McCaw, LK and Mann, M and Palme, R and Tissier, M and Uhlrich, P and Saraux, C and Viblanc, VA}, title = {Territorial scent-marking effects on vigilance behavior, space use, and stress in female Columbian ground squirrels.}, journal = {Hormones and behavior}, volume = {139}, number = {}, pages = {105111}, doi = {10.1016/j.yhbeh.2022.105111}, pmid = {35063725}, issn = {1095-6867}, mesh = {Animals ; Female ; Hydrocortisone ; *Lactation ; *Odorants ; Pheromones ; Sciuridae/physiology ; Territoriality ; }, abstract = {Social environments can profoundly affect the behavior and stress physiology of group-living animals. In many territorial species, territory owners advertise territorial boundaries to conspecifics by scent marking. Several studies have investigated the information that scent marks convey about donors' characteristics (e.g., dominance, age, sex, reproductive status), but less is known about whether scents affect the behavior and stress of recipients. We experimentally tested the hypothesis that scent marking may be a potent source of social stress in territorial species. We tested this hypothesis for Columbian ground squirrels (Urocitellus columbianus) during lactation, when territorial females defend individual nest-burrows against conspecifics. We exposed lactating females, on their territory, to the scent of other lactating females. Scents were either from unfamiliar females, kin relatives (a mother, daughter, or sister), or their own scent (control condition). We expected females to react strongly to novel scents from other females on their territory, displaying increased vigilance, and higher cortisol levels, indicative of behavioral and physiological stress. We further expected females to be more sensitive to unfamiliar female scents than to kin scents, given the matrilineal social structure of this species and known fitness benefits of co-breeding in female kin groups. Females were highly sensitive to intruder (both unfamiliar and kin) scents, but not to their own scent. Surprisingly, females reacted more strongly to the scent of close kin than to the scent of unfamiliar females. Vigilance behavior increased sharply in the presence of scents; this increase was more marked for kin than unfamiliar female scents, and was mirrored by a marked 131% increase in free plasma cortisol levels in the presence of kin (but not unfamiliar female) scents. Among kin scents, lactating females were more vigilant to the scent of sisters of equal age, but showed a marked 318% increase in plasma free cortisol levels in response to the scent of older and more dominant mothers. These results suggest that scent marks convey detailed information on the identity of intruders, directly affecting the stress axis of territory holders.}, }
@article {pmid35000446, year = {2022}, author = {Shimoji, H and Dobata, S}, title = {The build-up of dominance hierarchies in eusocial insects.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {377}, number = {1845}, pages = {20200437}, pmid = {35000446}, issn = {1471-2970}, mesh = {Animals ; *Ants/physiology ; Behavior, Animal/physiology ; Humans ; Reproduction/physiology ; Social Dominance ; *Wasps/physiology ; }, abstract = {Reproductive division of labour is a hallmark of eusocial insects. However, its stability can often be hampered by the potential for reproduction by otherwise sterile nest-mates. Dominance hierarchy has a crucial role in some species in regulating which individuals reproduce. Compared with those in vertebrates, the dominance hierarchies in eusocial insects tend to involve many more individuals, and should require additional selective forces unique to them. Here, we provide an overview of a series of studies on dominance hierarchies in eusocial insects. Although reported from diverse eusocial taxa, dominance hierarchies have been extensively studied in paper wasps and ponerine ants. Starting from molecular physiological attributes of individuals, we describe how the emergence of dominance hierarchies can be understood as a kind of self-organizing process through individual memory and local behavioural interactions. The resulting global structures can be captured by using network analyses. Lastly, we argue the adaptive significance of dominance hierarchies from the standpoint of sterile subordinates. Kin selection, underpinned by relatedness between nest-mates, is key to the subordinates' acceptance of their positions in the hierarchies. This article is part of the theme issue 'The centennial of the pecking order: current state and future prospects for the study of dominance hierarchies'.}, }
@article {pmid34953159, year = {2022}, author = {Walter, A and Bilde, T}, title = {Avoiding the tragedy of the commons: Improved group-feeding performance in kin groups maintains foraging cooperation in subsocial Stegodyphus africanus spiders (Araneae, Eresidae).}, journal = {Journal of evolutionary biology}, volume = {35}, number = {3}, pages = {391-399}, doi = {10.1111/jeb.13976}, pmid = {34953159}, issn = {1420-9101}, support = {624798/MCCC_/Marie Curie/United Kingdom ; }, mesh = {Animals ; *Spiders/physiology ; }, abstract = {Cooperation involving shared resource systems is prone to 'the tragedy of the commons', where individuals act in their own self-interest to exploit the resource in a manner that is detrimental to the common good of all group members. Directing cooperation towards kin provides a solution to this problem and predicts the differential performance depending on the relatedness of group members. In subsocial spiders, juveniles live in transient groups that cooperate in hunting and communal feeding. Prey capture is costly in terms of risk of injury and investment of venom and digestive enzymes, and therefore presents a situation where individuals may attempt to avoid costly interactions and exploit the resource acquired by other group members. We tested the prediction that individuals differentiate participation and/or investment in cooperative prey capture and extra-oral digestion (injection of digestive enzymes into prey prior to the initiation of extraction of nutrients) in response to the relatedness of group members with whom they interact, in the subsocial spider Stegodyphus africanus. The performance of groups and interactions over prey attack in groups of either related or mixed kin spiderlings were determined over a period of 4 weeks. We show that kin groups attack the prey significantly faster, recruit individuals to form feeding groups faster, extract prey body mass more efficiently and experience less antagonistic interactions than groups of mixed relatedness, which ultimately translates into an elevated growth rate. These results indicate that related individuals are more willing to take risks and invest in communal digestion when foraging with kin, as predicted by inclusive fitness theory as a solution to the tragedy of the commons.}, }
@article {pmid34949484, year = {2022}, author = {Rodrigues, AMM and Gardner, A}, title = {Reproductive value and the evolution of altruism.}, journal = {Trends in ecology &amp; evolution}, volume = {37}, number = {4}, pages = {346-358}, doi = {10.1016/j.tree.2021.11.007}, pmid = {34949484}, issn = {1872-8383}, support = {771387/ERC_/European Research Council/International ; }, mesh = {*Altruism ; Biological Evolution ; Female ; Humans ; Reproduction ; *Selection, Genetic ; }, abstract = {Altruism is favored by natural selection provided that it delivers sufficient benefits to relatives. An altruist's valuation of her relatives depends upon the extent to which they carry copies of her genes - relatedness - and also on the extent to which they are able to transmit their own genes to future generations - reproductive value. However, although relatedness has received a great deal of attention with regard to altruism, reproductive value has been surprisingly neglected. We review how reproductive value modulates patterns of altruism in relation to individual differences in age, sex, and general condition, and discuss how social partners may manipulate each other's reproductive value to incentivize altruism. This topic presents opportunities for tight interplay between theoretical and empirical research.}, }
@article {pmid34938490, year = {2021}, author = {Humphries, DJ and Nelson-Flower, MJ and Bell, MBV and Finch, FM and Ridley, AR}, title = {Kinship, dear enemies, and costly combat: The effects of relatedness on territorial overlap and aggression in a cooperative breeder.}, journal = {Ecology and evolution}, volume = {11}, number = {23}, pages = {17031-17042}, pmid = {34938490}, issn = {2045-7758}, abstract = {Many species maintain territories, but the degree of overlap between territories and the level of aggression displayed in territorial conflicts can vary widely, even within species. Greater territorial overlap may occur when neighboring territory holders are close relatives. Animals may also differentiate neighbors from strangers, with more familiar neighbors eliciting less-aggressive responses during territorial conflicts (the "dear enemy" effect). However, research is lacking in how both kinship and overlap affect territorial conflicts, especially in group-living species. Here, we investigate kinship, territorial overlap, and territorial conflict in a habituated wild population of group-living cooperatively breeding birds, the southern pied babbler Turdoides bicolor. We find that close kin neighbors are beneficial. Territories overlap more when neighboring groups are close kin, and these larger overlaps with kin confer larger territories (an effect not seen for overlaps with unrelated groups). Overall, territorial conflict is costly, causing significant decreases in body mass, but conflicts with kin are shorter than those conducted with nonkin. Conflicts with more familiar unrelated neighbors are also shorter, indicating these neighbors are "dear enemies." However, kinship modulates the "dear enemy" effect; even when kin are encountered less frequently, kin elicit less-aggressive responses, similar to the "dear enemy" effect. Kin selection appears to be a main influence on territorial behavior in this species. Groups derive kin-selected benefits from decreased conflicts and maintain larger territories when overlapping with kin, though not when overlapping with nonkin. More generally, it is possible that kinship extends the "dear enemy" effect in animal societies.}, }
@article {pmid34933602, year = {2021}, author = {Hitchcock, TJ and Gardner, A}, title = {Sex-biased demography modulates male harm across the genome.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1965}, pages = {20212237}, pmid = {34933602}, issn = {1471-2954}, mesh = {Biological Evolution ; Demography ; Female ; *Genome ; Humans ; Inheritance Patterns ; Male ; Reproduction ; *Sex Chromosomes ; }, abstract = {Recent years have seen an explosion of theoretical and empirical interest in the role that kin selection plays in shaping patterns of sexual conflict, with a particular focus on male harming traits. However, this work has focused solely on autosomal genes, and as such it remains unclear how demography modulates the evolution of male harm loci occurring in other portions of the genome, such as sex chromosomes and cytoplasmic elements. To investigate this, we extend existing models of sexual conflict for application to these different modes of inheritance. We first analyse the general case, revealing how sex-specific relatedness, reproductive value and the intensity of local competition combine to determine the potential for male harm. We then analyse a series of demographically explicit models, to assess how dispersal, overlapping generations, reproductive skew and the mechanism of population regulation affect sexual conflict across the genome, and drive conflict between nuclear and cytoplasmic genes. We then explore the effects of sex biases in these demographic parameters, showing how they may drive further conflicts between autosomes and sex chromosomes. Finally, we outline how different crossing schemes may be used to identify signatures of these intragenomic conflicts.}, }
@article {pmid34932965, year = {2021}, author = {Roy, SW}, title = {Sex determination: Ant supergenes link sex ratio to social structure.}, journal = {Current biology : CB}, volume = {31}, number = {24}, pages = {R1573-R1575}, doi = {10.1016/j.cub.2021.11.017}, pmid = {34932965}, issn = {1879-0445}, mesh = {Animals ; *Ants/genetics ; Reproduction ; *Sex Ratio ; Social Structure ; }, abstract = {A new study maps individual Formica ant queens' tendency to produce single-sex offspring to a so-called 'supergene' locus. This supergene neighbors another supergene determining social structure. Consequently, single-queen and multi-queen colonies disproportionately produce daughters and sons, respectively. This association mirrors the predictions of kin selection, though other possible explanations remain.}, }
@article {pmid34878556, year = {2022}, author = {Brodie, ED and Cook, PA and Costello, RA and Formica, VA}, title = {Phenotypic Assortment Changes the Landscape of Selection.}, journal = {The Journal of heredity}, volume = {113}, number = {1}, pages = {91-101}, doi = {10.1093/jhered/esab062}, pmid = {34878556}, issn = {1465-7333}, mesh = {Animals ; Biological Evolution ; Body Size ; *Coleoptera/genetics ; Male ; Phenotype ; Selection, Genetic ; *Social Behavior ; }, abstract = {Social interactions with conspecifics can dramatically affect an individual's fitness. The positive or negative consequences of interacting with social partners typically depend on the value of traits that they express. These pathways of social selection connect the traits and genes expressed in some individuals to the fitness realized by others, thereby altering the total phenotypic selection on and evolutionary response of traits across the multivariate phenotype. The downstream effects of social selection are mediated by the patterns of phenotypic assortment between focal individuals and their social partners (the interactant covariance, Cij', or the multivariate form, CI). Depending on the sign and magnitude of the interactant covariance, the direction of social selection can be reinforced, reversed, or erased. We report estimates of Cij' from a variety of studies of forked fungus beetles to address the largely unexplored questions of consistency and plasticity of phenotypic assortment in natural populations. We found that phenotypic assortment of male beetles based on body size or horn length was highly variable among subpopulations, but that those differences also were broadly consistent from year to year. At the same time, the strength and direction of Cij' changed quickly in response to experimental changes in resource distribution and social properties of populations. Generally, interactant covariances were more negative in contexts in which the number of social interactions was greater in both field and experimental situations. These results suggest that patterns of phenotypic assortment could be important contributors to variability in multilevel selection through their mediation of social selection gradients.}, }
@article {pmid34850889, year = {2022}, author = {McGlothlin, JW and Fisher, DN}, title = {Social Selection and the Evolution of Maladaptation.}, journal = {The Journal of heredity}, volume = {113}, number = {1}, pages = {61-68}, doi = {10.1093/jhered/esab061}, pmid = {34850889}, issn = {1465-7333}, mesh = {Adaptation, Physiological/genetics ; *Biological Evolution ; Genetic Fitness ; Phenotype ; *Selection, Genetic ; }, abstract = {Evolution by natural selection is often viewed as a process that inevitably leads to adaptation or an increase in population fitness over time. However, maladaptation, an evolved decrease in fitness, may also occur in response to natural selection under some conditions. Social selection, which arises from the effects of social partners on fitness, has been identified as a potential cause of maladaptation, but we lack a general rule identifying when social selection should lead to a decrease in population mean fitness. Here we use a quantitative genetic model to develop such a rule. We show that maladaptation is most likely to occur when social selection is strong relative to nonsocial selection and acts in an opposing direction. In this scenario, the evolution of traits that impose fitness costs on others may outweigh evolved gains in fitness for the individual, leading to a net decrease in population mean fitness. Furthermore, we find that maladaptation may also sometimes occur when phenotypes of interacting individuals negatively covary. We outline the biological situations where maladaptation in response to social selection can be expected, provide both quantitative genetic and phenotypic versions of our derived result, and suggest what empirical work would be needed to test it. We also consider the effect of social selection on inclusive fitness and support previous work showing that inclusive fitness cannot suffer an evolutionary decrease. Taken together, our results show that social selection may decrease population mean fitness when it opposes individual-level selection, even as inclusive fitness increases.}, }
@article {pmid34839709, year = {2022}, author = {Domingues, CPF and Rebelo, JS and Monteiro, F and Nogueira, T and Dionisio, F}, title = {Harmful behaviour through plasmid transfer: a successful evolutionary strategy of bacteria harbouring conjugative plasmids.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {377}, number = {1842}, pages = {20200473}, pmid = {34839709}, issn = {1471-2970}, mesh = {*Bacteria/genetics ; Biological Evolution ; *Conjugation, Genetic ; Plasmids/genetics ; }, abstract = {Conjugative plasmids are extrachromosomal mobile genetic elements pervasive among bacteria. Plasmids' acquisition often lowers cells' growth rate, so their ubiquity has been a matter of debate. Chromosomes occasionally mutate, rendering plasmids cost-free. However, these compensatory mutations typically take hundreds of generations to appear after plasmid arrival. By then, it could be too late to compete with fast-growing plasmid-free cells successfully. Moreover, arriving plasmids would have to wait hundreds of generations for compensatory mutations to appear in the chromosome of their new host. We hypothesize that plasmid-donor cells may use the plasmid as a 'weapon' to compete with plasmid-free cells, particularly in structured environments. Cells already adapted to plasmids may increase their inclusive fitness through plasmid transfer to impose a cost to nearby plasmid-free cells and increase the replication opportunities of nearby relatives. A mathematical model suggests conditions under which the proposed hypothesis works, and computer simulations tested the long-term plasmid maintenance. Our hypothesis explains the maintenance of conjugative plasmids not coding for beneficial genes. This article is part of the theme issue 'The secret lives of microbial mobile genetic elements'.}, }
@article {pmid34821809, year = {2021}, author = {Zhao, H and Liu, Y and Zhang, H and Breeze, TD and An, J}, title = {Worker-Born Males Are Smaller but Have Similar Reproduction Ability to Queen-Born Males in Bumblebees.}, journal = {Insects}, volume = {12}, number = {11}, pages = {}, pmid = {34821809}, issn = {2075-4450}, abstract = {Queen-worker conflict over the reproduction of males exists in the majority of haplodiplioidy hymenpteran species such as bees, wasps, and ants, whose workers lose mating ability but can produce haploid males in colony. Bumblebee is one of the representatives of primitively eusocial insects with plastic division labor and belongs to monandrous and facultative low polyandry species that have reproductive totipotent workers, which are capable of competing with mother queen to produce haploid males in the queenright colony compared to higher eusocial species, e.g., honeybees. So, bumblebees should be a better material to study worker reproduction, but the reproductive characteristics of worker-born males (WMs) remain unclear. Here, we choose the best-studied bumblebee Bombus terrestris to evaluate the morphological characteristics and reproductive ability of WMs from the queenless micro-colonies. The sexually matured WMs showed smaller in forewing length and weight, relatively less sperm counts but equally high sperm viability in comparison with the queen-born males (QMs) of the queenright colony. Despite with smaller size, the WMs are able to successfully mate with the virgin queens in competition with the QMs under laboratory conditions, which is quite different from the honeybees reported. In addition, there was no difference in the colony development, including the traits such as egg-laying rate, colony establishment rate, and populations of offspring, between the WM- and the QM-mated queens. Our study highlights the equivalent reproductive ability of worker-born males compared to that of queens, which might exhibit a positive application or special use of bumblebee rearing, especially for species whose males are not enough for copulation. Further, our finding contributes new evidence to the kin selection theory and suggests worker reproduction might relate to the evolution of sociality in bees.}, }
@article {pmid34803791, year = {2021}, author = {Chatterjee, D and Rai, R}, title = {Choosing Death Over Survival: A Need to Identify Evolutionary Mechanisms Underlying Human Suicide.}, journal = {Frontiers in psychology}, volume = {12}, number = {}, pages = {689022}, pmid = {34803791}, issn = {1664-1078}, abstract = {The act of killing self contradicts the central purpose of human evolution, that is, survival and propagation of one's genetic material. Yet, it continues to be one of the leading causes of human death. A handful of theories in the realm of evolutionary psychology have attempted to explain human suicide. The current article analyses the major components of certain prominent viewpoints, namely, Inclusive fitness, Bargaining model, Pain-Brain model, Psychological aposematism, and few other perspectives. The article argues that relatively more weightage has been given to understanding ultimate (the "why") rather than proximate (the "how") functionality of suicidal acts. Evolutionary theorists have consistently pointed out that to comprehensively understand a trait or behavior, one needs to delineate not only how it supports survival but also the evolution of the mechanisms underlying the trait or behavior. Existing theories on suicide have primarily focused on its fitness benefits on surviving kin instead of providing evolutionary explanations of the more complex mechanisms leading up to such self-destructive motivations. Thus, the current paper attempts to highlight this gap in theorizing while suggesting probable proximate explanations of suicide which stresses the need to diffuse attention paid to fitness consequences of the act alone. We speculate that such explorations are needed in order to build a robust and comprehensive evolutionary theory of human suicide.}, }
@article {pmid34798134, year = {2022}, author = {Raymond, B and Erdos, Z}, title = {Passage and the evolution of virulence in invertebrate pathogens: Fundamental and applied perspectives.}, journal = {Journal of invertebrate pathology}, volume = {187}, number = {}, pages = {107692}, doi = {10.1016/j.jip.2021.107692}, pmid = {34798134}, issn = {1096-0805}, support = {BB/S002928/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Baculoviridae ; *Biological Evolution ; Fungi/genetics ; *Nematoda ; Virulence ; }, abstract = {Understanding the ecological and genetic factors that determine the evolution of virulence has broad value for invertebrate pathology. In addition to helping us understand the fundamental biology of our study organisms this body of theory has important applications in microbial biocontrol. Experimental tests of virulence theory are often carried out in invertebrate models and yet theory rarely informs applied passage experiments that aim to increase or maintain virulence. This review summarizes recent progress in this field with a focus on work most relevant to biological control: the virulence of invertebrate pathogens that are 'obligate killers' and which require cadavers for the production of infectious propagules. We discuss recent theory and fundamental and applied experimental evolution with bacteria, fungi, baculoviruses and nematodes. While passage experiments using baculoviruses have a long history of producing isolates with increased virulence, studies with other pathogens have not been so successful. Recent passage experiments that have applied evolution of virulence frameworks based on cooperation (kin selection) have produced novel methods and promising mutants with increased killing power. Evolution of virulence theory can provide plausible explanations for the varied results of passage experiments as well as a predictive framework for improving artificial selection.}, }
@article {pmid34793823, year = {2022}, author = {Denton, KK and Ram, Y and Feldman, MW}, title = {Conformity and content-biased cultural transmission in the evolution of altruism.}, journal = {Theoretical population biology}, volume = {143}, number = {}, pages = {52-61}, doi = {10.1016/j.tpb.2021.10.004}, pmid = {34793823}, issn = {1096-0325}, mesh = {Alleles ; *Altruism ; Biological Evolution ; *Cultural Evolution ; Humans ; Phenotype ; Social Behavior ; }, abstract = {The evolution of altruism has been extensively modeled under the assumption of genetic transmission, whereas the dynamics under cultural transmission are less well understood. Previous research has shown that cultural transmission can facilitate the evolution of altruism by increasing (1) the probability of adopting the altruistic phenotype, and (2) assortment between altruists. We incorporate vertical and oblique transmission, which can be conformist or anti-conformist, into models of parental care, sibling altruism, and altruism between individuals that meet assortatively. If oblique transmission is conformist, it becomes easier for altruism to invade a population of non-altruists as the probability of vertical transmission increases. If oblique transmission is anti-conformist, decreasing vertical transmission facilitates invasion by altruism in the assortative meeting model, whereas in other models, there is a trade-off: greater vertical transmission produces greater assortment among genetically related altruists, but lowers the probability of adopting altruism via anti-conformity. Compared to conditions for invasion under genetic transmission, e.g., Hamilton's rule, we show that invasion can be easier with sufficiently strong anti-conformity, and in some models, with sufficiently high assortment even if oblique transmission is conformist. We also explore invasion by an allele A that increases individuals' content bias for altruism, in the absence of other forms of cultural transmission. If costs and benefits combine additively, A invades under previously known conditions. If costs and benefits combine multiplicatively, invasion by A and by altruism become more difficult than in the corresponding additive models.}, }
@article {pmid34702072, year = {2021}, author = {Grof-Tisza, P and Karban, R and Rasheed, MU and Saunier, A and Blande, JD}, title = {Risk of herbivory negatively correlates with the diversity of volatile emissions involved in plant communication.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1961}, pages = {20211790}, pmid = {34702072}, issn = {1471-2954}, mesh = {Animals ; *Artemisia ; Herbivory ; Humans ; Insecta ; Plants ; *Volatile Organic Compounds ; }, abstract = {Plant-to-plant volatile-mediated communication and subsequent induced resistance to insect herbivores is common. Less clear is the adaptive significance of these interactions; what selective mechanisms favour plant communication and what conditions allow individuals to benefit by both emitting and responding to cues? We explored the predictions of two non-exclusive hypotheses to explain why plants might emit cues, the kin selection hypothesis (KSH) and the mutual benefit hypothesis (MBH). We examined 15 populations of sagebrush that experience a range of naturally occurring herbivory along a 300 km latitudinal transect. As predicted by the KSH, we found several uncommon chemotypes with some chemotypes occurring only within a single population. Consistent with the MBH, chemotypic diversity was negatively correlated with herbivore pressure; sites with higher levels of herbivory were associated with a few common cues broadly recognized by most individuals. These cues varied among different populations. Our results are similar to those reported for anti-predator signalling in vertebrates.}, }
@article {pmid34669158, year = {2021}, author = {Fisktjønmo, GLH and Næss, MW and Bårdsen, BJ}, title = {The Relative Importance of "Cooperative Context" and Kinship in Structuring Cooperative Behavior : A Comparative Study of Saami Reindeer Herders.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {32}, number = {4}, pages = {677-705}, pmid = {34669158}, issn = {1936-4776}, support = {240280//Norges Forskningsr&#xe5;d/ ; 76915//Nordic Centre of Excellence/ ; 362257//The Terrestrial flagship, Fram Centre/ ; 369902//The Terrestrial flagship, Fram Centre/ ; }, mesh = {Animals ; *Cooperative Behavior ; Farmers ; Humans ; *Reindeer ; }, abstract = {Kin relations have a strong theoretical and empirical basis for explaining cooperative behavior. Nevertheless, there is growing recognition that context-the cooperative environment of an individual-also shapes the willingness of individuals to cooperate. For nomadic pastoralists in Norway, cooperation among both kin and non-kin is an essential predictor for success. The northern parts of the country are characterized by a history of herder-herder competition exacerbating between-herder conflict, lack of trust, and subsequent coordination problems. In contrast, because of a history of herder-farmer competition, southern Norway is characterized by high levels of between-herder coordination and trust. This comparative study investigates the relative importance of "cooperative context" and kinship in structuring cooperative behavior using an experimental gift game. The main findings from this study were that in the South, a high level of cooperation around an individual pushes gifts to be distributed evenly among other herders. Nevertheless, kinship matters, since close kin give and receive larger gifts. In contrast, kinship seems to be the main factor affecting gift distribution in the North. Herders in the North are also concerned with distributing gifts equally, albeit limiting them to close kin: the level of intragroup cooperation drives gifts to be distributed evenly among other closely related herders. The observed regional contrasts in cooperative decisions fit with the different historical levels of conflict and trust in the two regions: whereas herders in the South are affected by both cooperative context and kinship, kinship seems to be the main determinant of cooperation in the North.}, }
@article {pmid34657470, year = {2021}, author = {Zwolak, R and Clement, D and Sih, A and Schreiber, SJ}, title = {Mast seeding promotes evolution of scatter-hoarding.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {376}, number = {1839}, pages = {20200375}, pmid = {34657470}, issn = {1471-2970}, mesh = {Animals ; *Fagus ; Feeding Behavior ; *Hoarding ; Mice ; Reproduction ; Seeds ; }, abstract = {Many plant species worldwide are dispersed by scatter-hoarding granivores: animals that hide seeds in numerous, small caches for future consumption. Yet, the evolution of scatter-hoarding is difficult to explain because undefended caches are at high risk of pilferage. Previous models have attempted to solve this problem by giving cache owners large advantages in cache recovery, by kin selection, or by introducing reciprocal pilferage of 'shared' seed resources. However, the role of environmental variability has been so far overlooked in this context. One important form of such variability is masting, which is displayed by many plant species dispersed by scatterhoarders. We use a mathematical model to investigate the influence of masting on the evolution of scatter-hoarding. The model accounts for periodically varying annual seed fall, caching and pilfering behaviour, and the demography of scatterhoarders. The parameter values are based mostly on research on European beech (Fagus sylvatica) and yellow-necked mice (Apodemus flavicollis). Starvation of scatterhoarders between mast years decreases the population density that enters masting events, which leads to reduced seed pilferage. Satiation of scatterhoarders during mast events lowers the reproductive cost of caching (i.e. the cost of caching for the future rather than using seeds for current reproduction). These reductions promote the evolution of scatter-hoarding behaviour especially when interannual variation in seed fall and the period between masting events are large. This article is part of the theme issue 'The ecology and evolution of synchronized seed production in plants'.}, }
@article {pmid34627803, year = {2021}, author = {Lessard, S and Li, C and Zheng, XD and Tao, Y}, title = {Inclusive fitness and Hamilton's rule in a stochastic environment.}, journal = {Theoretical population biology}, volume = {142}, number = {}, pages = {91-99}, doi = {10.1016/j.tpb.2021.09.007}, pmid = {34627803}, issn = {1096-0325}, mesh = {*Biological Evolution ; Cooperative Behavior ; Game Theory ; Haploidy ; *Prisoner Dilemma ; Probability ; }, abstract = {The evolution of cooperation in Prisoner's Dilemmas with additive random cost and benefit for cooperation cannot be accounted for by Hamilton's rule based on mean effects transferred from recipients to donors weighted by coefficients of relatedness, which defines inclusive fitness in a constant environment. Extensions that involve higher moments of stochastic effects are possible, however, and these are connected to a concept of random inclusive fitness that is frequency-dependent. This is shown in the setting of pairwise interactions in a haploid population with the same coefficient of relatedness between interacting players. In an infinite population, fixation of cooperation is stochastically stable if a mean geometric inclusive fitness of defection when rare is negative, while fixation of defection is stochastically unstable if a mean geometric inclusive fitness of cooperation when rare is positive, and these conditions are generally not equivalent. In a finite population, the probability for cooperation to ultimately fix when represented once exceeds the probability under neutrality or the corresponding probability for defection if the mean inclusive fitness of cooperation when its frequency is 1/3 or 1/2, respectively, exceeds 1. All these results rely on the simplifying assumption of a linear fitness function. It is argued that meaningful applications of random inclusive fitness in complex settings (multi-player game, diploidy, population structure) would generally require conditions of weak selection and additive gene action.}, }
@article {pmid34616345, year = {2021}, author = {Tanskanen, AO and Danielsbacka, M and Hämäläinen, H and Solé-Auró, A}, title = {Does Transition to Retirement Promote Grandchild Care? Evidence From Europe.}, journal = {Frontiers in psychology}, volume = {12}, number = {}, pages = {738117}, pmid = {34616345}, issn = {1664-1078}, abstract = {Evolutionary theory posits that grandparents can increase their inclusive fitness by investing in their grandchildren. This study explored whether the transition to retirement affected the amount of grandchild care that European grandparents provided to their descendants. Data from five waves of the longitudinal Survey of Health, Aging, and Retirement in Europe collected between 2004 and 2015 from 15 countries were used. We executed within-person (or fixed-effect) regression models, which considered individual variations and person-specific changes over time. It was detected that transition to retirement was associated with increased grandchild care among both grandmothers and grandfathers. However, the effect of retirement was stronger for grandfathers than for grandmothers. Moreover, transition to retirement was associated with increased grandchild care among both maternal and paternal grandparents, but there was no significant difference between lineages in the magnitude of the effect of transition to retirement on grandchild care. In public debate retirees are often considered a burden to society but the present study indicated that when grandparents retire, their investment in grandchildren increased. The findings are discussed with reference to key evolutionary theories that consider older adults' tendency to invest time and resources in their grandchildren.}, }
@article {pmid34592345, year = {2021}, author = {Leonardo, DE and Nogueira-Filho, SLG and de Góes Maciel, F and Biondo, C and Mendl, M and Nogueira, SSDC}, title = {Third-party conflict interventions are kin biased in captive white-lipped peccaries (Mammalia, Tayassuidae).}, journal = {Behavioural processes}, volume = {193}, number = {}, pages = {104524}, doi = {10.1016/j.beproc.2021.104524}, pmid = {34592345}, issn = {1872-8308}, mesh = {Aggression ; Animals ; *Artiodactyla ; Humans ; Male ; Mammals ; Social Behavior ; }, abstract = {Third-party interventions may regulate conflicts to reduce aggression and promote cohesion amongst group members, but are rarely documented in ungulates. The white-lipped peccary (Tayassu pecari) lives in mixed-sex herds of hundreds of individuals in Neotropical forests, which are likely to benefit from mechanisms that sustain social cohesiveness. We examined third-party conflict interventions between individuals in captive groups of white-lipped peccaries. During a period of 60 days, we recorded agonistic interactions and occurrences of third-party conflict interventions, and estimated the genetic relatedness between the individuals involved using multilocus microsatellite genotypes. Most third-party conflict interventions were by the dominant male of each group, resulting in conflict termination 100% of the time. Our results also revealed that white-lipped peccaries favour their closest relatives and that individuals showed lower levels of aggression towards kin than to non-kin, and interventions on behalf of kin were more frequent than on behalf of non-kin. Our findings support the idea that genetic relatedness is fundamental in both social structure and third-party conflict interventions in this species, allowing us to suggest that kin selection could have a key role in the evolution of social behaviour of white-lipped peccaries.}, }
@article {pmid34555177, year = {2021}, author = {Josi, D and Heg, D and Takeyama, T and Bonfils, D and Konovalov, DA and Frommen, JG and Kohda, M and Taborsky, M}, title = {Age- and sex-dependent variation in relatedness corresponds to reproductive skew, territory inheritance, and workload in cooperatively breeding cichlids.}, journal = {Evolution; international journal of organic evolution}, volume = {75}, number = {11}, pages = {2881-2897}, pmid = {34555177}, issn = {1558-5646}, mesh = {Animals ; Breeding ; *Cichlids/genetics ; Humans ; Social Structure ; Workload ; }, abstract = {Kin selection plays a major role in the evolution of cooperative systems. However, many social species exhibit complex within-group relatedness structures, where kin selection alone cannot explain the occurrence of cooperative behavior. Understanding such social structures is crucial to elucidate the evolution and maintenance of multi-layered cooperative societies. In lamprologine cichlids, intragroup relatedness seems to correlate positively with reproductive skew, suggesting that in this clade dominants tend to provide reproductive concessions to unrelated subordinates to secure their participation in brood care. We investigate how patterns of within-group relatedness covary with direct and indirect fitness benefits of cooperation in a highly social vertebrate, the cooperatively breeding, polygynous lamprologine cichlid Neolamprologus savoryi. Behavioral and genetic data from 43 groups containing 578 individuals show that groups are socially and genetically structured into subgroups. About 17% of group members were unrelated immigrants, and average relatedness between breeders and brood care helpers declined with helper age due to group membership dynamics. Hence the relative importance of direct and indirect fitness benefits of cooperation depends on helper age. Our findings highlight how both direct and indirect fitness benefits of cooperation and group membership can select for cooperative behavior in societies comprising complex social and relatedness structures.}, }
@article {pmid34530032, year = {2021}, author = {Priklopil, T and Lehmann, L}, title = {Metacommunities, fitness and gradual evolution.}, journal = {Theoretical population biology}, volume = {142}, number = {}, pages = {12-35}, doi = {10.1016/j.tpb.2021.09.002}, pmid = {34530032}, issn = {1096-0325}, mesh = {*Biological Evolution ; *Models, Genetic ; Phenotype ; Population Dynamics ; Selection, Genetic ; }, abstract = {We analyze the evolution of a multidimensional quantitative trait in a class-structured focal species interacting with other species in a wider metacommunity. The evolutionary dynamics in the focal species as well as the ecological dynamics of the whole metacommunity is described as a continuous-time process with birth, physiological development, dispersal, and death given as rates that can depend on the state of the whole metacommunity. This can accommodate complex local community and global metacommunity environmental feedbacks owing to inter- and intra-specific interactions, as well as local environmental stochastic fluctuations. For the focal species, we derive a fitness measure for a mutant allele affecting class-specific trait expression. Using classical results from geometric singular perturbation theory, we provide a detailed proof that if the effect of the mutation on phenotypic expression is small ("weak selection"), the large system of dynamical equations needed to describe selection on the mutant allele in the metacommunity can be reduced to a single ordinary differential equation on the arithmetic mean mutant allele frequency that is of constant sign. This invariance on allele frequency entails the mutant either dies out or will out-compete the ancestral resident (or wild) type. Moreover, the directional selection coefficient driving arithmetic mean allele frequency can be expressed as an inclusive fitness effect calculated from the resident metacommunity alone, and depends, as expected, on individual fitness differentials, relatedness, and reproductive values. This formalizes the Darwinian process of gradual evolution driven by random mutation and natural selection in spatially and physiologically class-structured metacommunities.}, }
@article {pmid34424594, year = {2021}, author = {Premate, E and Borko, &#x160; and Kralj-Fišer, S and Jennions, M and Fišer, &#x17d; and Balázs, G and Bíró, A and Bračko, G and Copilaş-Ciocianu, D and Hrga, N and Herczeg, G and Rexhepi, B and Zagmajster, M and Zakšek, V and Fromhage, L and Fišer, C}, title = {No room for males in caves: Female-biased sex ratio in subterranean amphipods of the genus Niphargus.}, journal = {Journal of evolutionary biology}, volume = {34}, number = {10}, pages = {1653-1661}, doi = {10.1111/jeb.13917}, pmid = {34424594}, issn = {1420-9101}, mesh = {*Amphipoda/genetics ; Animals ; Caves ; Ecosystem ; Female ; Male ; Phylogeny ; Sex Ratio ; }, abstract = {Sex allocation theory predicts that the proportion of daughters to sons will evolve in response to ecological conditions that determine the costs and benefits of producing each sex. All else being equal, the adult sex ratio (ASR) should also vary with ecological conditions. Many studies of subterranean species reported female-biased ASR, but no systematic study has yet been conducted. We test the hypothesis that the ASR becomes more female-biased with increased isolation from the surface. We compiled a data set of ASRs of 35 species in the subterranean amphipod Niphargus, each living in one of three distinct habitats (surface-subterranean boundary, cave streams, phreatic lakes) representing an environmental gradient of increased isolation underground. The ASR was female-biased in 27 of 35 species; the bias was statistically significant in 12 species. We found a significant difference in the ASR among habitats after correction for phylogeny. It is most weakly female-biased at the surface-subterranean boundary and most strongly female-biased in phreatic lakes. Additional modelling suggests that the ASR has evolved towards a single value for both surface-subterranean boundary and cave stream-dwelling species, and another value for 9 of 11 phreatic lake dwellers. We suggest that a history of inbreeding in subterranean populations might lower inbreeding depression such that kin selection favours mating with siblings. This could select for a female-biased offspring sex ratio due to local mate competition among brothers. The observed patterns in sex ratios in subterranean species make them a group worthy of more attention from those interested in sex allocation theory.}, }
@article {pmid34403632, year = {2021}, author = {Croft, DP and Weiss, MN and Nielsen, MLK and Grimes, C and Cant, MA and Ellis, S and Franks, DW and Johnstone, RA}, title = {Kinship dynamics: patterns and consequences of changes in local relatedness.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1957}, pages = {20211129}, pmid = {34403632}, issn = {1471-2954}, mesh = {Female ; Humans ; *Menopause ; *Social Behavior ; Social Evolution ; }, abstract = {Mounting evidence suggests that patterns of local relatedness can change over time in predictable ways, a process termed kinship dynamics. Kinship dynamics may occur at the level of the population or social group, where the mean relatedness across all members of the population or group changes over time, or at the level of the individual, where an individual's relatedness to its local group changes with age. Kinship dynamics are likely to have fundamental consequences for the evolution of social behaviour and life history because they alter the inclusive fitness payoffs to actions taken at different points in time. For instance, growing evidence suggests that individual kinship dynamics have shaped the evolution of menopause and age-specific patterns of helping and harming. To date, however, the consequences of kinship dynamics for social evolution have not been widely explored. Here we review the patterns of kinship dynamics that can occur in natural populations and highlight how taking a kinship dynamics approach has yielded new insights into behaviour and life-history evolution. We discuss areas where analysing kinship dynamics could provide new insight into social evolution, and we outline some of the challenges in predicting and quantifying kinship dynamics in natural populations.}, }
@article {pmid34391806, year = {2021}, author = {He, QQ and Zheng, XD and Mace, R and Tao, Y and Ji, T}, title = {Hamilton's rule and kin competition in a finite kin population.}, journal = {Journal of theoretical biology}, volume = {529}, number = {}, pages = {110862}, doi = {10.1016/j.jtbi.2021.110862}, pmid = {34391806}, issn = {1095-8541}, mesh = {*Altruism ; *Biological Evolution ; Humans ; }, abstract = {Kin selection means that individuals can increase their own inclusive fitness through displaying more altruistically toward their relatives. So, Hamilton's rule says kin selection will work if the coefficient of relatedness exceeds the cost-to-benefit ratio of the altruistic act. However, some studies have shown that the kin competition due to the altruism among relatives can reduce, and even totally negate, the kin-selected benefits of altruism toward relatives. In order to understand how the evolution of cooperation is influenced by both kin selection and kin competition under a general theoretical framework, we here consider the evolutionary dynamics of cooperation in a finite kin population, where kin competition is incorporated into a simple Prisoner's Dilemma game between relatives. Differently from the previous studies, we emphasize that the difference between the effects of mutually and unilaterally altruistic acts on kin competition may play an important role for the evolution of cooperation. The main results not only show the conditions that Hamilton's rule still works under the kin competition but also reveal the evolutionary biological mechanism driving the evolution of cooperation in a finite kin population.}, }
@article {pmid34367662, year = {2021}, author = {Iritani, R and West, SA and Abe, J}, title = {Cooperative interactions among females can lead to even more extraordinary sex ratios.}, journal = {Evolution letters}, volume = {5}, number = {4}, pages = {370-384}, pmid = {34367662}, issn = {2056-3744}, abstract = {Hamilton's local mate competition theory provided an explanation for extraordinary female-biased sex ratios in a range of organisms. When mating takes place locally, in structured populations, a female-biased sex ratio is favored to reduce competition between related males, and to provide more mates for males. However, there are a number of wasp species in which the sex ratios appear to more female biased than predicted by Hamilton's theory. It has been hypothesized that the additional female bias in these wasp species results from cooperative interactions between females. We investigated theoretically the extent to which cooperation between related females can interact with local mate competition to favor even more female-biased sex ratios. We found that (i) cooperation between females can lead to sex ratios that are more female biased than predicted by local competition theory alone, and (ii) sex ratios can be more female biased when the cooperation occurs from offspring to mothers before dispersal, rather than cooperation between siblings after dispersal. Our models formally confirm the verbal predictions made in previous experimental studies, which could be applied to a range of organisms. Specifically, cooperation can help explain sex ratio biases in Sclerodermus and Melittobia wasps, although quantitative comparisons between predictions and data suggest that some additional factors may be operating.}, }
@article {pmid34366975, year = {2021}, author = {Novakova, J and Machová, K and Sýkorová, K and Zíka, V and Flegr, J}, title = {Looking Like a Million Dollars: Does Attractiveness Priming Increase Altruistic Behavior in Experimental Games?.}, journal = {Frontiers in psychology}, volume = {12}, number = {}, pages = {658466}, pmid = {34366975}, issn = {1664-1078}, abstract = {The emergence of altruistic behavior constitutes one of the most widely studied problems in evolutionary biology and behavioral science. Multiple explanations have been proposed, most importantly including kin selection, reciprocity, and costly signaling in sexual selection. In order to test the latter, this study investigated whether people behave more altruistically when primed by photographs of attractive faces and whether more or less altruistic people differ in the number of sexual and romantic partners. Participants in the general population (N = 158, 84 F, 74 M) first rated the attractiveness of photographs of 20 faces of the opposite (sexually preferred) sex and then played the Dictator and Ultimatum Games (DG and UG). The photograph rating acted as priming; half the participants received photographs of people rated as more attractive than average in an earlier study, and the other half received photographs previously rated as less attractive. The attractiveness-primed participants, especially men, were expected to behave more altruistically-signaling that they are desirable, resource-possessing partners. We also expected altruists to self-report more sexual and romantic partners. The observed difference between altruistic behaviors in the attractiveness- and unattractiveness-primed groups occurred in UG offers, however, in the opposite than expected direction in women. The number of sexual partners was positively correlated to minimum acceptable offers (MAOs) in the UG, in line with expectations based on the theory of costly signaling.}, }
@article {pmid34344179, year = {2021}, author = {Lymbery, SJ and Tomkins, JL and Buzatto, BA and Hosken, DJ}, title = {Kin-mediated plasticity in alternative reproductive tactics.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1956}, pages = {20211069}, pmid = {34344179}, issn = {1471-2954}, mesh = {*Acaridae ; Animals ; Humans ; Male ; *Mites ; Phenotype ; Population Density ; Reproduction ; Sexual Behavior, Animal ; }, abstract = {Conditional strategies occur when the relative fitness pay-off from expressing a given phenotype is contingent upon environmental circumstances. This conditional strategy model underlies cases of alternative reproductive tactics, in which individuals of one sex employ different means to obtain reproduction. How kin structure affects the expression of alternative reproductive tactics remains unexplored. We address this using the mite Rhizoglyphus echinopus, in which large males develop into aggressive 'fighters' and small males develop into non-aggressive 'scramblers.' Because only fighters kill their rivals, they should incur a greater indirect fitness cost when competing with their relatives, and thus fighter expression could be reduced in the presence of relatives. We raised mites in full-sibling or mixed-sibship groups and found that fighters were more common at higher body weights in full-sibling groups, not less common as we predicted (small individuals were almost exclusively scramblers in both treatments). This result could be explained if relatedness and cue variability are interpreted signals of population density, since fighters are more common at low densities in this species. Alternatively, our results may indicate that males compete more intensely with relatives in this species. We provide the first evidence of kin-mediated plasticity in the expression of alternative reproductive tactics.}, }
@article {pmid34330328, year = {2021}, author = {Nikolajsen, H and Richardson, EV and Sandal, LF and Juul-Kristensen, B and Troelsen, J}, title = {Fitness for all: how do non-disabled people respond to inclusive fitness centres?.}, journal = {BMC sports science, medicine &amp; rehabilitation}, volume = {13}, number = {1}, pages = {81}, pmid = {34330328}, issn = {2052-1847}, abstract = {BACKGROUND: Representation of people with disabilities in fitness centres is lacking, despite initiatives to promote inclusion mainly in the UK and USA. Success creating these inclusive spaces is mixed and few were crafted taking into account attitudes and biases of non-disabled co-members. Inclusive fitness centres have not gained much attention in Denmark, and the campaign 'Fitness for All - fitness for people with physical disabilities' was initiated. The aim of this study was shaped by two key questions; 1) what is the ideal fitness space from the perception of non-disabled fitness users? and 2) how might their dis/ableist attitudes negate inclusion in three future pilot inclusive fitness centres across Denmark?<br><br>METHOD: Three focus groups involving 5-7 (total n&#x2009;=&#x2009;18) adult non-disabled participants were conducted. Aged ranged between 19 and 75&#xa0;years, both men and women were involved, with fitness centre experiences ranging from 0 to 20+ years. Interviews were transcribed and analysed using Malterud's four-step method of systematic text condensation.<br><br>RESULTS: Of most importance was a pleasant atmosphere which should make them feel welcome and comfortable. Good social relations within the space were also highly valued. Participants welcomed people with physical disabilities but predicted many challenges with an inclusive fitness centre and expressed unconscious ableist attitudes.<br><br>CONCLUSION: The current study adds essential knowledge regarding how non-disabled people perceive the ideal inclusive fitness centre. A welcoming and inviting atmosphere is essential whereas social skills, ableism, ignorance, and preconceptions are important barriers that may hinder inclusion of participants with disabilities in inclusive fitness centres.}, }
@article {pmid34309511, year = {2021}, author = {Bensch, HM and O'Connor, EA and Cornwallis, CK}, title = {Living with relatives offsets the harm caused by pathogens in natural populations.}, journal = {eLife}, volume = {10}, number = {}, pages = {}, pmid = {34309511}, issn = {2050-084X}, mesh = {Animals ; *Behavior, Animal ; Ecology ; *Genetic Variation ; Microsatellite Repeats ; Phylogeny ; Reproduction ; *Social Behavior ; Survival ; }, abstract = {Living with relatives can be highly beneficial, enhancing reproduction and survival. High relatedness can, however, increase susceptibility to pathogens. Here, we examine whether the benefits of living with relatives offset the harm caused by pathogens, and if this depends on whether species typically live with kin. Using comparative meta-analysis of plants, animals, and a bacterium (nspecies = 56), we show that high within-group relatedness increases mortality when pathogens are present. In contrast, mortality decreased with relatedness when pathogens were rare, particularly in species that live with kin. Furthermore, across groups variation in mortality was lower when relatedness was high, but abundances of pathogens were more variable. The effects of within-group relatedness were only evident when pathogens were experimentally manipulated, suggesting that the harm caused by pathogens is masked by the benefits of living with relatives in nature. These results highlight the importance of kin selection for understanding disease spread in natural populations.}, }
@article {pmid34305981, year = {2021}, author = {Subrahmaniam, HJ and Roby, D and Roux, F}, title = {Toward Unifying Evolutionary Ecology and Genomics to Understand Positive Plant-Plant Interactions Within Wild Species.}, journal = {Frontiers in plant science}, volume = {12}, number = {}, pages = {683373}, pmid = {34305981}, issn = {1664-462X}, abstract = {In a local environment, plant networks include interactions among individuals of different species and among genotypes of the same species. While interspecific interactions are recognized as main drivers of plant community patterns, intraspecific interactions have recently gained attention in explaining plant community dynamics. However, an overview of intraspecific genotype-by-genotype interaction patterns within wild plant species is still missing. From the literature, we identified 91 experiments that were mainly designed to investigate the presence of positive interactions based on two contrasting hypotheses. Kin selection theory predicts partisan help given to a genealogical relative. The rationale behind this hypothesis relies on kin/non-kin recognition, with the positive outcome of kin cooperation substantiating it. On the other hand, the elbow-room hypothesis supports intraspecific niche partitioning leading to positive outcome when genetically distant genotypes interact. Positive diversity-productivity relationship rationalizes this hypothesis, notably with the outcome of overyielding. We found that both these hypotheses have been highly supported in experimental studies despite their opposite predictions between the extent of genetic relatedness among neighbors and the level of positive interactions. Interestingly, we identified a highly significant effect of breeding system, with a high proportion of selfing species associated with the presence of kin cooperation. Nonetheless, we identified several shortcomings regardless of the species considered, such as the lack of a reliable estimate of genetic relatedness among genotypes and ecological characterization of the natural habitats from which genotypes were collected, thereby impeding the identification of selective drivers of positive interactions. We therefore propose a framework combining evolutionary ecology and genomics to establish the eco-genomic landscape of positive GxG interactions in wild plant species.}, }
@article {pmid34302740, year = {2021}, author = {Teunissen, N and Kingma, SA and Fan, M and Roast, MJ and Peters, A}, title = {Context-dependent social benefits drive cooperative predator defense in a bird.}, journal = {Current biology : CB}, volume = {31}, number = {18}, pages = {4120-4126.e4}, doi = {10.1016/j.cub.2021.06.070}, pmid = {34302740}, issn = {1879-0445}, mesh = {Animals ; Biological Evolution ; Cooperative Behavior ; Humans ; *Passeriformes/physiology ; Reproduction/physiology ; Social Behavior ; *Songbirds/physiology ; }, abstract = {Understanding the major evolutionary transition from solitary individuals to complex societies is hampered by incomplete insight into the drivers of living in cooperative groups.[1-3] This may be because the benefits of sociality can derive from group living itself (e.g., dilution of predation risk),[4][,][5] or depend on social context (e.g., kin or potential mates represent beneficial group members).[6-8] Cooperative breeders, where non-breeding subordinates assist breeders, have provided important insights into the drivers of cooperation, but comprehensive assessment of diverse potential benefits has been hindered by a prevailing focus on benefits deriving from raising offspring.[9-11] We propose a novel paradigm to tease apart different benefits by comparing cooperative responses to predators threatening dependent young and adult group members according to their value for the responding individual. Applying this approach in purple-crowned fairy-wrens, Malurus coronatus, we show that non-breeding subordinates are more responsive to nest predators-a threat to offspring-when their probability of inheriting a breeding position is greater-irrespective of group size, relatedness to offspring, or opportunity to showcase individual quality to potential mates. This suggests that offspring defense is modulated according to the benefits of raising future helpers. Conversely, when predators pose a threat to adults, responsiveness depends on social context: subordinates respond more often when kin or potential mates are under threat, or when group members are associated with mutualistic social bonds, indirect genetic benefits, and future reproductive benefits.[9][,][12][,][13] Our results demonstrate that direct and kin-selected benefits of sociality are context dependent, and highlight the importance of predation risk in driving complex sociality.}, }
@article {pmid34290628, year = {2021}, author = {Hollon, SD and Andrews, PW and Thomson, JA}, title = {Cognitive Behavior Therapy for Depression From an Evolutionary Perspective.}, journal = {Frontiers in psychiatry}, volume = {12}, number = {}, pages = {667592}, pmid = {34290628}, issn = {1664-0640}, abstract = {Evolutionary medicine attempts to solve a problem with which traditional medicine has struggled historically; how do we distinguish between diseased states and "healthy" responses to disease states? Fever and diarrhea represent classic examples of evolved adaptations that increase the likelihood of survival in response to the presence of pathogens in the body. Whereas, the severe mental disorders like psychotic mania or the schizophrenias may involve true "disease" states best treated pharmacologically, most non-psychotic "disorders" that revolve around negative affects like depression or anxiety are likely adaptations that evolved to serve a function that increased inclusive fitness in our ancestral past. What this likely means is that the proximal mechanisms underlying the non-psychotic "disorders" are "species typical" and neither diseases nor disorders. Rather, they are coordinated "whole body" responses that prepare the individual to respond in a maximally functional fashion to the variety of different challenges that our ancestors faced. A case can be made that depression evolved to facilitate a deliberate cognitive style (rumination) in response to complex (often social) problems. What this further suggests is that those interventions that best facilitate the functions that those adaptations evolved to serve (such as rumination) are likely to be preferred over those like medications that simply anesthetize the distress. We consider the mechanisms that evolved to generate depression and the processes utilized in cognitive behavior therapy to facilitate those functions from an adaptationist evolutionary perspective.}, }
@article {pmid34270793, year = {2021}, author = {Barra, T and Viblanc, VA and Saraux, C and Murie, JO and Dobson, FS}, title = {Parental investment in the Columbian ground squirrel: empirical tests of sex allocation models.}, journal = {Ecology}, volume = {102}, number = {11}, pages = {e03479}, doi = {10.1002/ecy.3479}, pmid = {34270793}, issn = {1939-9170}, mesh = {Animals ; Biological Evolution ; Female ; Male ; *Reproduction ; Sciuridae ; Selection, Genetic ; *Sex Ratio ; }, abstract = {Parental allocation of resources into male or female offspring and differences in the balance of offspring sexes in natural populations are central research topics in evolutionary ecology. Fisher (Fisher, R. A. 1930. The genetical theory of natural selection, Clarendon Press, Oxford, UK) identified frequency-dependent selection as the mechanism responsible for an equal investment in the sexes of offspring at the end of parental care. Three main theories have been proposed for explaining departures from Fisherian sex ratios in light of variation in environmental (social) and individual (maternal condition) characteristics. The Trivers-Willard model (Trivers, R., and D. Willard. 1973. Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90-92) of male-biased sex allocation by mothers in the best body condition is based on the competitive ability of male offspring for future access to mates and thus superior reproduction. The local resource competition model is based on competitive interactions in matrilines, as occur in many mammal species, where producing sons reduces future intrasexual competition with daughters. A final model invokes advantages of maintaining matrilines for philopatric females, despite any increased competition among females. We used 29 yr of pedigree and demographic data to evaluate these hypotheses in the Colombian ground squirrel (Urocitellus columbianus), a semisocial species characterized by strong female philopatry. Overall, male offspring were heavier than female offspring at birth and at weaning, suggesting a higher production cost. With more local kin present, mothers in the best condition biased their offspring sex ratio in favor of males, and mothers in poor condition biased offspring sex ratio in favor of females. Without co-breeding close kin, the pattern was reversed, with mothers in the best condition producing more daughters, and mothers in poor condition producing more sons. Our results do not provide strong support for any of the single-factor models of allocation to the sexes of offspring, but rather suggest combined influences of relative maternal condition and matriline dominance on offspring sex ratio.}, }
@article {pmid34238997, year = {2021}, author = {Arnot, M and Mace, R}, title = {An evolutionary perspective on kin care directed up the generations.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {14163}, pmid = {34238997}, issn = {2045-2322}, mesh = {Adolescent ; Adult ; *Biological Evolution ; *Caregivers ; Child ; *Family ; Female ; Fertility ; Humans ; Middle Aged ; Models, Biological ; Parents ; Young Adult ; }, abstract = {Within evolutionary sciences, care towards younger kin is well understood from an inclusive fitness framework, but why adults would care for older relatives has been less well researched. One existing model has argued that care directed towards elderly parents might be adaptive because of their benefits as carers themselves, with their help freeing up the middle generations' energy which can then be invested into direct reproduction. However, in this model, elder care is more beneficial to fitness if the carer is fecund. To offer an initial test of this hypothesis, we look at caring behaviour relative to fecundity status in a contemporary dataset from the United Kingdom. If elder care is contingent on possible direct fitness benefits, we would expect women who are still menstruating to care more for their parents than women who can no longer reproduce. Based on this, we also predict that women who are physiologically post-reproductive would invest more in their grandchildren, through whom they can increase their inclusive fitness. After controlling for age and other relevant factors, we find that women who are still menstruating spend more time caring for their parents than those who are not, and the reverse is true when looking at time spent caring for grandchildren. These findings demonstrate that potential inclusive fitness outcomes influence how women allocate care up and down the generations.}, }
@article {pmid34201317, year = {2021}, author = {Ando, J and Kawamoto, T}, title = {Genetic and Environmental Structure of Altruism Characterized by Recipients in Relation to Personality.}, journal = {Medicina (Kaunas, Lithuania)}, volume = {57}, number = {6}, pages = {}, pmid = {34201317}, issn = {1648-9144}, support = {FY2013-FY2015//TopicSetting Program to Advanced Cutting-Edge Humanities and Social Sciences Research/ ; }, mesh = {Adult ; *Altruism ; Family ; Humans ; *Personality/genetics ; Self Report ; }, abstract = {Background and Objectives: Altruism is a form of prosocial behavior with the goal of increasing the fitness of another individual as a recipient while reducing the fitness of the actor. Although there are many studies on its heterogeneity, only a few behavioral genetic studies have been conducted to examine different recipient types: family members favored by kin selection, the dynamic network of friends and acquaintances as direct reciprocity, and strangers as indirect reciprocity. Materials and Methods: This study investigated the genetic and environmental structure of altruism with reference to recipient types measured by the self-report altruism scale distinguished by the recipient (the SRAS-DR) and examine the relationship to personality dimensions measured by the NEO-FFI with a sample of 461 adult Japanese twin pairs. Results: The present study shows that there is a single common factor of altruism: additive genetic effects explain 51% of altruism without a shared environmental contribution. The genetic contribution of this single common factor is explained by the genetic factors of neuroticism (N), extraversion (E), openness to experience (O), and conscientiousness (C), as well as a common genetic factor specific to altruism. Only altruism toward strangers is affected by shared environmental factors. Conclusions: Different types of altruistic personality are constructed by specific combinational profiles of general personality traits such as the Big Five as well as a genetic factor specific to altruism in each specific way.}, }
@article {pmid34193863, year = {2021}, author = {He, Y and Xu, H and Liu, H and Luo, M and Chu, C and Fang, S}, title = {Sexual competition and kin recognition co-shape the traits of neighboring dioecious Diospyros morrisiana seedlings.}, journal = {Horticulture research}, volume = {8}, number = {1}, pages = {162}, pmid = {34193863}, issn = {2662-6810}, support = {31370441//National Science Foundation of China | National Natural Science Foundation of China-Yunnan Joint Fund (NSFC-Yunnan Joint Fund)/ ; 31670628//National Science Foundation of China | National Natural Science Foundation of China-Yunnan Joint Fund (NSFC-Yunnan Joint Fund)/ ; }, abstract = {Plants respond differently to the identity of their neighbors, such as their sex and kinship, showing plasticity in their traits. However, how the functional traits of dioecious trees are shaped by the recognition of neighbors with different sex and kinship remains unknown. In this study, we set up an experiment with different kin/nonkin and inter/intrasexual combinations for a dioecious tree species, Diospyros morrisiana. The results showed that plants grew better with nonkin and intrasexual neighbors than with kin and intersexual neighbors. Kin combinations had significantly shorter root length in the resource-overlapping zone than nonkin combinations, suggesting that kin tended to reduce competition by adjusting their root distribution, especially among female siblings. Our study suggested that the seedling growth of D. morrisiana was affected by both the relatedness and sexual identity of neighboring plants. Further analysis by gas chromatography-mass spectrometry showed that the root exudate composition of female seedlings differed from that of male seedlings. Root exudates may play important roles in sex competition in dioecious plants. This study indicates that sex-specific competition and kin recognition interact and co-shape the traits of D. morrisiana seedlings, while intrasexual and nonkin neighbors facilitate the growth of seedlings. Our study implies that kin- and sex-related interactions depend on different mechanisms, kin selection, and niche partitioning, respectively. These results are critical for understanding how species coexist and how traits are shaped in nature.}, }
@article {pmid34150907, year = {2021}, author = {Daly, M and Perry, G}, title = {In-Law Relationships in Evolutionary Perspective: The Good, the Bad, and the Ugly.}, journal = {Frontiers in sociology}, volume = {6}, number = {}, pages = {683501}, pmid = {34150907}, issn = {2297-7775}, abstract = {In-laws (relatives by marriage) are true kin because the descendants that they have in common make them "vehicles" of one another's inclusive fitness. From this shared interest flows cooperation and mutual valuation: the good side of in-law relationships. But there is also a bad side. Recent theoretical models err when they equate the inclusive fitness value of corresponding pairs of genetic and affinal (marital) relatives-brother and brother-in-law, daughter and daughter-in-law-partly because a genetic relative's reproduction always replicates ego's genes whereas reproduction by an affine may not, and partly because of distinct avenues for nepotism. Close genetic relatives compete, often fiercely, over familial property, but the main issues in conflict among marital relatives are different and diverse: fidelity and paternity, divorce and autonomy, and inclinations to invest in distinct natal kindreds. These conflicts can get ugly, even lethal. We present the results of a pilot study conducted in Bangladesh which suggests that heightened mortality arising from mother-in-law/daughter-in-law conflict may be a two-way street, and we urge others to replicate and extend these analyses.}, }
@article {pmid34067982, year = {2021}, author = {Kalbarczyk, M}, title = {Non-Financial Support Provided to Parents in Stepfamilies: Empirical Examination of Europeans 50.}, journal = {International journal of environmental research and public health}, volume = {18}, number = {10}, pages = {}, pmid = {34067982}, issn = {1660-4601}, mesh = {Child ; *Divorce ; Ethnicity ; Europe ; Humans ; *Marriage ; White People ; }, abstract = {The aging of the population, coupled with increasing divorce and remarriage rates, are changing the structure of potential non-financial support for older parents. The purpose of this study was to examine support provided to parents aged 50+ in stepfamilies and to determine if the difference existed between help provided by natural children and stepchildren. The primary objective was to investigate whether blood ties were a significant determinant of the support if the quality of the relationship between the parent and a natural child or a stepchild was taken into account. The secondary objective was to answer the question to what extent the reciprocal exchange motive of support was observed in stepfamilies. The probability of non-financial support from children and stepchildren was estimated based on the sixth wave of the SHARE (Survey on Health, Ageing, and Retirement in Europe) database for European countries. Children in stepfamilies provided less non-financial help to parents than those in intact families. Stepchildren were less likely to be in stepparents' social networks, and stepparents provided less help with childcare for grandchildren than they did to their biological children. Relationship closeness and looking after grandchildren increased the probability of non-financial support to older parents, regardless of whether the donor was a natural child or a stepchild.}, }
@article {pmid37588530, year = {2021}, author = {Kerry, N and Blake, KR and Murray, DR and Brooks, RC}, title = {Male descendant kin promote conservative views on gender issues and conformity to traditional norms.}, journal = {Evolutionary human sciences}, volume = {3}, number = {}, pages = {e34}, pmid = {37588530}, issn = {2513-843X}, abstract = {Political and social attitudes have been shown to differ by sex in a way that tracks individual self-interest. We propose that these attitudes also change strategically to serve the best interests of either male or female kin. To test this hypothesis, we developed a measure of gendered fitness interests (GFI) - an index which reflects the sex, relatedness and residual reproductive value of close kin. We predicted that people with male-biased GFI (i.e. people with more male kin of a reproductive age) would have more conservative attitudes towards gender-related issues (e.g. gender roles, women's rights, abortion rights). An online study using an American sample (N = 560) found support for this hypothesis. Further analyses revealed that this relationship was driven not only by people's own sex and reproductive value but also by those of their descendant kin. Exploratory analyses also found a positive association between male-biased GFI and a measure of conformity, as well as a smaller association between male-biased GFI and having voted Republican in the last election. Both of these associations were statistically mediated by gender-related conservatism. These findings are consistent with the hypothesis that GFI influences sociopolitical attitudes.}, }
@article {pmid34039054, year = {2021}, author = {Rezvani Nejad, S and Borjali, A and Khanjani, M and Kruger, DJ}, title = {Belief in an Afterlife Influences Altruistic Helping Intentions in Alignment With Adaptive Tendencies.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {19}, number = {2}, pages = {14747049211011745}, pmid = {34039054}, issn = {1474-7049}, mesh = {*Altruism ; Biological Evolution ; Humans ; *Intention ; Iran ; Reproduction ; Selection, Genetic ; }, abstract = {Evolutionary definitions of altruism are only concerned with reproductive consequences and not motives or other psychological mechanisms, making them ideal for generalization to all forms of organisms. Hamilton's inclusive fitness theory explains altruistic behavior toward genetic relatives and has generated extensive empirical support. Trivers' theory of reciprocal altruism helps explain patterns of helping among non-kin, and other research has demonstrated that human helping intentions follow fitness consequences from age-based reproductive value on altruism. The current study examines a novel psychological factor, belief in the afterlife, which may influence altruistic helping intentions. Belief in the afterlife was incorporated into a previous study design assessing the effects of a target's genetic relatedness and age-based reproductive value. The influences of inclusive fitness and target age were reproduced in a non-Western sample of participants (N = 300) in Iran. Belief in the afterlife predicted the overall confidence of risking one's life to save another across all targets, and also moderated the effects of genetic relatedness and target age. Rather than promoting altruism equitably or advantaging those favored by adaptive tendencies, higher belief in an afterlife aligned with these tendencies in promoting further favoritism toward close kin and younger targets with higher reproductive value.}, }
@article {pmid34007461, year = {2021}, author = {Caicoya, AL and Colell, M and Ensenyat, C and Amici, F}, title = {Problem solving in European bison (Bison bonasus): two experimental approaches.}, journal = {Royal Society open science}, volume = {8}, number = {4}, pages = {201901}, pmid = {34007461}, issn = {2054-5703}, abstract = {The ability to solve novel problems is crucial for individual fitness. However, studies on problem solving are usually done on few taxa, with species with low encephalization quotient being rarely tested. Here, we aimed to study problem solving in a non-domesticated ungulate species, European bison, with two experimental tasks. In the first task, five individuals were presented with a hanging barrel filled with food, which could either be directly accessed (control condition) or which could only be reached by pushing a tree stump in the enclosure below it and stepping on it (experimental condition). In the second task, five individuals were repeatedly fed by an experimenter using a novel bucket to retrieve food from a bag. Then, three identical buckets were placed in the enclosure, while the experimenter waited outside with the bag without feeding the bison, either with a bucket (control condition) or without it (experimental condition). In the first task, no bison moved the stump behind the barrel and/or stepped on it to reach the food. In the second task, two individuals solved the task by pushing the bucket within the experimenter's reach, twice in the experimental and twice in the control condition. We suggest that bison showed a limited ability to solve novel problems, and discuss the implications for their understanding of the functional aspects of the tasks.}, }
@article {pmid34004128, year = {2021}, author = {Smith, J and Inglis, RF}, title = {Evaluating kin and group selection as tools for quantitative analysis of microbial data.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1951}, pages = {20201657}, pmid = {34004128}, issn = {1471-2954}, mesh = {*Biological Evolution ; *Selection, Genetic ; Social Behavior ; Social Evolution ; }, abstract = {Kin selection and multilevel selection theory are often used to interpret experiments about the evolution of cooperation and social behaviour among microbes. But while these experiments provide rich, detailed fitness data, theory is mostly used as a conceptual heuristic. Here, we evaluate how kin and multilevel selection theory perform as quantitative analysis tools. We reanalyse published microbial datasets and show that the canonical fitness models of both theories are almost always poor fits because they use statistical regressions misspecified for the strong selection and non-additive effects we show are widespread in microbial systems. We identify analytical practices in empirical research that suggest how theory might be improved, and show that analysing both individual and group fitness outcomes helps clarify the biology of selection. A data-driven approach to theory thus shows how kin and multilevel selection both have untapped potential as tools for quantitative understanding of social evolution in all branches of life.}, }
@article {pmid33972440, year = {2021}, author = {Abe, J and Iritani, R and Tsuchida, K and Kamimura, Y and West, SA}, title = {A solution to a sex ratio puzzle in Melittobia wasps.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {20}, pages = {}, pmid = {33972440}, issn = {1091-6490}, mesh = {Animal Distribution/*physiology ; Animals ; Clutch Size/*genetics ; Competitive Behavior/physiology ; Cooperative Behavior ; Female ; Male ; Oviposition/*genetics ; *Sex Ratio ; Wasps/*genetics ; Zygote/growth &amp; development ; }, abstract = {The puzzling sex ratio behavior of Melittobia wasps has long posed one of the greatest questions in the field of sex allocation. Laboratory experiments have found that, in contrast to the predictions of theory and the behavior of numerous other organisms, Melittobia females do not produce fewer female-biased offspring sex ratios when more females lay eggs on a patch. We solve this puzzle by showing that, in nature, females of Melittobia australica have a sophisticated sex ratio behavior, in which their strategy also depends on whether they have dispersed from the patch where they emerged. When females have not dispersed, they lay eggs with close relatives, which keeps local mate competition high even with multiple females, and therefore, they are selected to produce consistently female-biased sex ratios. Laboratory experiments mimic these conditions. In contrast, when females disperse, they interact with nonrelatives, and thus adjust their sex ratio depending on the number of females laying eggs. Consequently, females appear to use dispersal status as an indirect cue of relatedness and whether they should adjust their sex ratio in response to the number of females laying eggs on the patch.}, }
@article {pmid33970458, year = {2021}, author = {Singletary, B}, title = {Learning Through Shared Care : Allomaternal Care Impacts Cognitive Development in Early Infancy in a Western Population.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {32}, number = {2}, pages = {326-362}, pmid = {33970458}, issn = {1936-4776}, support = {BCS-1752542//Division of Behavioral and Cognitive Sciences/ ; Reicker Grants and W &amp; N Sullivan Scholarship Fund//School of Anthropology, University of Arizona/ ; Graduate Fellowship//Confluencenter for Creative Inquiry, University of Arizona/ ; Dissertation Research Grant//Social and Behavioral Sciences Research Institute, University of Arizona (US)/ ; Research and Project Grant//Graduate and Professional Student Council, University of Arizona (US)/ ; }, mesh = {*Cognition ; Female ; Humans ; Infant ; *Learning ; Mothers ; Surveys and Questionnaires ; }, abstract = {This study investigates how allomaternal care (AMC) impacts human development outside of energetics by evaluating relations between important qualitative and quantitative aspects of AMC and developmental outcomes in a Western population. This study seeks to determine whether there are measurable differences in cognitive and language outcomes as predicted by differences in exposure to AMC via formal (e.g., childcare facilities) and informal (e.g., family and friends) networks. Data were collected from 102 mothers and their typically developing infants aged 13-18 months. AMC predictor data were collected using questionnaires, structured daily diaries, and longitudinal interviews. Developmental outcomes were assessed using the Cognitive, Receptive Language, and Expressive Language subtests of the Bayley III Screening Test. Additional demographic covariates were also evaluated. Akaike Information Criterion (AIC)-informed model selection was used to identify the best-fitting model for each outcome across three working linear regression models. Although AMC variables had no significant effects on Receptive and Expressive Language subtest scores, highly involved familial AMC had a significant medium effect on Cognitive subtest score (β = 0.23, p < 0.01, semi-partial r = 0.28). Formal childcare had no effect on any outcome. This study provides preliminary evidence that there is a measurable connection between AMC and cognitive development in some populations and provides a methodological base from which to assess these connections cross-culturally through future studies. As these effects are attributable to AMC interactions with networks of mostly related individuals, these findings present an area for further investigation regarding the kin selection hypothesis for AMC.}, }
@article {pmid33957580, year = {2021}, author = {Minnameyer, A and Strobl, V and Bruckner, S and Camenzind, DW and Van Oystaeyen, A and Wäckers, F and Williams, GR and Yañez, O and Neumann, P and Straub, L}, title = {Eusocial insect declines: Insecticide impairs sperm and feeding glands in bumblebees.}, journal = {The Science of the total environment}, volume = {785}, number = {}, pages = {146955}, doi = {10.1016/j.scitotenv.2021.146955}, pmid = {33957580}, issn = {1879-1026}, mesh = {Animals ; Bees ; Female ; Humans ; Insecta ; *Insecticides/toxicity ; Male ; Neonicotinoids/toxicity ; Nitro Compounds/toxicity ; Reproduction ; Spermatozoa ; Thiamethoxam ; }, abstract = {Insecticides are contributing to global insect declines, thereby creating demand to understand the mechanisms underlying reduced fitness. In the eusocial Hymenoptera, inclusive fitness depends on successful mating of male sexuals (drones) and efficient collaborative brood care by female workers. Therefore, sublethal insecticide effects on sperm and glands used in larval feeding (hypopharyngeal glands (HPG)) would provide key mechanisms for population declines in eusocial insects. However, while negative impacts for bumblebee colony fitness have been documented, the effects of insecticide exposure on individual physiology are less well understood. Here, we show that field-realistic concentrations (4.5-40 ng ml[-1]) of the neonicotinoid insecticide thiamethoxam significantly impair Bombus terrestris sperm and HPGs, thereby providing plausible mechanisms underlying bumblebee population decline. In the laboratory, drones and workers were exposed to five thiamethoxam concentrations (4.5 to 1000 ng ml[-1]). Then, survival, food consumption, body mass, HPG development, sperm quantity and viability were assessed. At all concentrations, drones were more exposed than workers due to higher food consumption. Increased body mass was observed in drones starting at 20 ng ml[-1] and in workers at 100 ng ml[-1]. Furthermore, environmentally realistic concentrations (4.5-40 ng ml[-1]) did not significantly affect survival or consumption for either sex. However, thiamethoxam exposure significantly negatively affected both sperm viability and HPG development at all tested concentrations. Therefore, the results indicate a trade-off between survival and fitness components, possibly due to costly detoxification. Since sperm and HPG are corner stones of colony fitness, the data offer plausible mechanisms for bumblebee population declines. To adequately mitigate ongoing biodiversity declines for the eusocial insects, this study suggests it is essential to evaluate the impact of insecticides on fitness parameters of both sexuals and workers.}, }
@article {pmid33941905, year = {2021}, author = {de Boer, RA and Vega-Trejo, R and Kotrschal, A and Fitzpatrick, JL}, title = {Meta-analytic evidence that animals rarely avoid inbreeding.}, journal = {Nature ecology &amp; evolution}, volume = {5}, number = {7}, pages = {949-964}, pmid = {33941905}, issn = {2397-334X}, mesh = {Animals ; Female ; Humans ; *Inbreeding ; Male ; *Mating Preference, Animal ; Reproduction ; }, abstract = {Animals are usually expected to avoid mating with relatives (kin avoidance) as incestuous mating can lead to the expression of inbreeding depression. Yet, theoretical models predict that unbiased mating with regards to kinship should be common, and that under some conditions, the inclusive fitness benefits associated with inbreeding can even lead to a preference for mating with kin. This mismatch between empirical and theoretical expectations generates uncertainty as to the prevalence of inbreeding avoidance in animals. Here, we synthesized 677 effect sizes from 139 experimental studies of mate choice for kin versus non-kin in diploid animals, representing 40 years of research, using a meta-analytical approach. Our meta-analysis revealed little support for the widely held view that animals avoid mating with kin, despite clear evidence of publication bias. Instead, unbiased mating with regards to kinship appears widespread across animals and experimental conditions. The significance of a variety of moderators was explored using meta-regressions, revealing that the degree of relatedness and prior experience with kin explained some variation in the effect sizes. Yet, we found no difference in kin avoidance between males and females, choice and no-choice experiments, mated and virgin animals or between humans and animals. Our findings highlight the need to rethink the widely held view that inbreeding avoidance is a given in experimental studies.}, }
@article {pmid33938278, year = {2021}, author = {Schacht, R and Meeks, H and Fraser, A and Smith, KR}, title = {Was Cinderella just a fairy tale? Survival differences between stepchildren and their half-siblings.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {376}, number = {1827}, pages = {20200032}, pmid = {33938278}, issn = {1471-2970}, support = {R01 AG022095/AG/NIA NIH HHS/United States ; }, mesh = {Adolescent ; Child ; Child, Preschool ; *Family Characteristics ; Fathers/*statistics &amp; numerical data ; Female ; Humans ; Infant ; Male ; Marriage/*statistics &amp; numerical data ; Mortality ; Mothers/*statistics &amp; numerical data ; Siblings/*psychology ; *Social Support ; Utah ; }, abstract = {The death of a parent, particularly the mother, is linked to a suite of negative outcomes across the life-course. Compounding concerns for child outcomes are expectations of poor treatment by step-parents after parental remarriage. Indeed, folk tales of step-parental abuse abound cross-culturally and are embedded into stories taught to children. To understand why child outcomes might be sensitive to levels of relatedness within the household, evolutionary-oriented research targets patterning in parental expenditure in ways predicted to maximize inclusive fitness. In particular, parents are expected to prioritize investments in their biological children. However, stepfamilies are only formed after children experience multiple unfortunate events (e.g. parental loss, poverty), blurring causal interpretations between step-parental presence and stepchild outcomes. Moreover, stepchildren have been shown to be integral to household functioning, caring for their half-siblings and stabilizing relationships. These results challenge narrow views of adaptive behaviour; specifically, that step-parents, unlike biological parents, do no stand to reap fitness benefits from the care that they provide to their stepchildren. To evaluate these critiques, we analyse the survival outcomes of stepchildren. We include over 400 000 individuals from across a natural fertility period (1847-1940) in the United States state of Utah and examine the consequences of parental loss and step-parental introduction. Our analyses yield three key results: (i) exposure to maternal loss in childhood is associated with elevated mortality risk, (ii) parental remarriage does not increase the risk of mortality among stepchildren compared to non-stepchildren who too had lost a parent, and (iii) stepchildren enjoy higher survival than their half-siblings within the same family. Ultimately, this work contributes to the increasingly recognized importance of cooperative relationships among non-kin for childcare and household functioning. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'.}, }
@article {pmid33934419, year = {2021}, author = {Garcia-Costoya, G and Fromhage, L}, title = {Realistic genetic architecture enables organismal adaptation as predicted under the folk definition of inclusive fitness.}, journal = {Journal of evolutionary biology}, volume = {34}, number = {7}, pages = {1087-1094}, doi = {10.1111/jeb.13795}, pmid = {33934419}, issn = {1420-9101}, mesh = {Altruism ; Biological Evolution ; Genetic Fitness ; *Models, Genetic ; Phenotype ; *Selection, Genetic ; }, abstract = {A fundamental task of evolutionary biology is to explain the pervasive impression of organismal design in nature, including traits benefiting kin. Inclusive fitness is considered by many to be a crucial piece in this puzzle, despite ongoing discussion about its scope and limitations. Here, we use individual-based simulations to study what quantity (if any) individual organisms become adapted to maximize when genetic architectures are more or less suitable for the presumed main driver of biological adaptation, namely cumulative multi-locus evolution. As an expository device, we focus on a hypothetical situation called Charlesworth's paradox, in which altruism is seemingly predicted to evolve, yet altruists immediately perish along with their altruistic genes. Our results support a recently proposed re-definition of inclusive fitness, which is concerned with the adaptive design of whole organisms as shaped by multi-locus evolution, rather than with selection for any focal gene. They also illustrate how our conceptual understanding of adaptation at the phenotypic level should inform our choice of genetic assumptions in abstract simplified models.}, }
@article {pmid33908829, year = {2021}, author = {Flintham, EO and Savolainen, V and Mullon, C}, title = {Dispersal Alters the Nature and Scope of Sexually Antagonistic Variation.}, journal = {The American naturalist}, volume = {197}, number = {5}, pages = {543-559}, doi = {10.1086/713739}, pmid = {33908829}, issn = {1537-5323}, mesh = {Alleles ; *Animal Distribution ; Animals ; Female ; Genetic Drift ; *Genetic Variation ; Male ; *Selection, Genetic ; Sex Characteristics ; }, abstract = {AbstractIntralocus sexual conflict, or sexual antagonism, occurs when alleles have opposing fitness effects in the two sexes. Previous theory suggests that sexual antagonism is a driver of genetic variation by generating balancing selection. However, most of these studies assume that populations are well mixed, neglecting the effects of spatial subdivision. Here, we use mathematical modeling to show that limited dispersal changes evolution at sexually antagonistic autosomal and X-linked loci as a result of inbreeding and sex-specific kin competition. We find that if the sexes disperse at different rates, kin competition within the philopatric sex biases intralocus conflict in favor of the more dispersive sex. Furthermore, kin competition diminishes the strength of balancing selection relative to genetic drift, reducing genetic variation in small subdivided populations. Meanwhile, by decreasing heterozygosity, inbreeding reduces the scope for sexually antagonistic polymorphism due to nonadditive allelic effects, and this occurs to a greater extent on the X chromosome than autosomes. Overall, our results indicate that spatial structure is a relevant factor in predicting where sexually antagonistic alleles might be observed. We suggest that sex-specific dispersal ecology and demography can contribute to interspecific and intragenomic variation in sexual antagonism.}, }
@article {pmid33878926, year = {2021}, author = {González-Forero, M and Peña, J}, title = {Eusociality through conflict dissolution.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1949}, pages = {20210386}, pmid = {33878926}, issn = {1471-2954}, mesh = {Female ; *Biological Evolution ; Pheromones ; Reproduction ; *Social Behavior ; Solubility ; Animals ; }, abstract = {Eusociality, where largely unreproductive offspring help their mothers reproduce, is a major form of social organization. An increasingly documented feature of eusociality is that mothers induce their offspring to help by means of hormones, pheromones or behavioural displays, with evidence often indicating that offspring help voluntarily. The co-occurrence of maternal influence and offspring voluntary help may be explained by what we call the converted helping hypothesis, whereby maternally manipulated helping subsequently becomes voluntary. Such hypothesis requires that parent-offspring conflict is eventually dissolved-for instance, if the benefit of helping increases sufficiently over evolutionary time. We show that help provided by maternally manipulated offspring can enable the mother to sufficiently increase her fertility to transform parent-offspring conflict into parent-offspring agreement. This conflict-dissolution mechanism requires that helpers alleviate maternal life-history trade-offs, and results in reproductive division of labour, high queen fertility and honest queen signalling suppressing worker reproduction-thus exceptionally recovering diverse features of eusociality. As such trade-off alleviation seemingly holds widely across eusocial taxa, this mechanism offers a potentially general explanation for the origin of eusociality, the prevalence of maternal influence, and the offspring's willingness to help. Overall, our results explain how a major evolutionary transition can happen from ancestral conflict.}, }
@article {pmid33866807, year = {2021}, author = {Oldroyd, BP and Yagound, B}, title = {Parent-of-origin effects, allele-specific expression, genomic imprinting and paternal manipulation in social insects.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {376}, number = {1826}, pages = {20200425}, pmid = {33866807}, issn = {1471-2970}, mesh = {Alleles ; Animals ; *Epigenesis, Genetic ; Genomic Imprinting ; Hymenoptera/*genetics ; Isoptera/*genetics ; *Maternal Inheritance ; *Paternal Inheritance ; Social Behavior ; }, abstract = {Haplo-diploidy and the relatedness asymmetries it generates mean that social insects are prime candidates for the evolution of genomic imprinting. In single-mating social insect species, some genes may be selected to evolve genomic mechanisms that enhance reproduction by workers when they are inherited from a female. This situation reverses in multiple mating species, where genes inherited from fathers can be under selection to enhance the reproductive success of daughters. Reciprocal crosses between subspecies of honeybees have shown strong parent-of-origin effects on worker reproductive phenotypes, and this could be evidence of such genomic imprinting affecting genes related to worker reproduction. It is also possible that social insect fathers directly affect gene expression in their daughters, for example, by placing small interfering RNA molecules in semen. Gene expression studies have repeatedly found evidence of parent-specific gene expression in social insects, but it is unclear at this time whether this arises from genomic imprinting, paternal manipulation, an artefact of cyto-nuclear interactions, or all of these. This article is part of the theme issue 'How does epigenetics influence the course of evolution?'}, }
@article {pmid33756043, year = {2021}, author = {Boots, M and Childs, D and Crossmore, J and Tidbury, H and Rudolf, V}, title = {Experimental evidence that local interactions select against selfish behaviour.}, journal = {Ecology letters}, volume = {24}, number = {6}, pages = {1187-1192}, doi = {10.1111/ele.13734}, pmid = {33756043}, issn = {1461-0248}, support = {NSF DEB- 0841686//National Science Foundation/ ; NSF DEB-1256860//National Science Foundation/ ; NIH/R01-GM122061-03/GM/NIGMS NIH HHS/United States ; NE/J009784/1//Natural Environment Research Council/ ; NIH/R01-GM122061-03/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Biological Evolution ; *Cannibalism ; Larva ; Models, Biological ; *Social Behavior ; }, abstract = {How social behaviours evolve remains one of the most debated questions in evolutionary biology. An important theoretical prediction is that when organisms interact locally due to limited dispersal or strong social ties, the population structure that emerges may favour cooperation over antagonism. We carry out an experimental test of this theory by directly manipulating population spatial structure in an insect laboratory model system and measuring the impact on the evolution of the extreme selfish behaviour of cannibalism. We show that, as predicted by the theory, Indian meal moth larvae that evolved in environments with more limited dispersal are selected for lower rates of cannibalism. This is important because it demonstrates that local interactions select against selfish behaviour. Therefore, the ubiquitous variation in population structure that we see in nature is a simple mechanism that can help to explain the variation in selfish and cooperative behaviours that we see in nature.}, }
@article {pmid33755538, year = {2021}, author = {Martyn, TE and Stouffer, DB and Godoy, O and Bartomeus, I and Pastore, AI and Mayfield, MM}, title = {Identifying "Useful" Fitness Models: Balancing the Benefits of Added Complexity with Realistic Data Requirements in Models of Individual Plant Fitness.}, journal = {The American naturalist}, volume = {197}, number = {4}, pages = {415-433}, doi = {10.1086/713082}, pmid = {33755538}, issn = {1537-5323}, mesh = {*Genetic Fitness ; *Models, Biological ; *Plants ; }, abstract = {AbstractDirect species interactions are commonly included in individual fitness models used for coexistence and local diversity modeling. Though widely considered important for such models, direct interactions alone are often insufficient for accurately predicting fitness, coexistence, or diversity outcomes. Incorporating higher-order interactions (HOIs) can lead to more accurate individual fitness models but also adds many model terms, which can quickly result in model overfitting. We explore approaches for balancing the trade-off between tractability and model accuracy that occurs when HOIs are added to individual fitness models. To do this, we compare models parameterized with data from annual plant communities in Australia and Spain, varying in the extent of information included about the focal and neighbor species. The best-performing models for both data sets were those that grouped neighbors based on origin status and life form, a grouping approach that reduced the number of model parameters substantially while retaining important ecological information about direct interactions and HOIs. Results suggest that the specific identity of focal or neighbor species is not necessary for building well-performing fitness models that include HOIs. In fact, grouping neighbors by even basic functional information seems sufficient to maximize model accuracy, an important outcome for the practical use of HOI-inclusive fitness models.}, }
@article {pmid33755537, year = {2021}, author = {Patten, MM}, title = {On Being a Monkey's Uncle: Germline Chimerism in the Callitrichinae and the Evolution of Sibling Rivalry.}, journal = {The American naturalist}, volume = {197}, number = {4}, pages = {502-508}, doi = {10.1086/713110}, pmid = {33755537}, issn = {1537-5323}, mesh = {Animals ; *Biological Evolution ; Callitrichinae/*genetics ; *Chimerism ; Female ; Male ; *Models, Biological ; *Sibling Relations ; }, abstract = {AbstractA typical monkey of the subfamily Callitrichinae has two or more cell lineages occupying its tissues: one from "itself," and one from its co-twin(s). Chimerism originates in utero when the twin placentae fuse, vascular anastomoses form between them, and cells are exchanged between conceptuses through their shared circulation. Previously it was thought that chimerism was limited to tissues of the hematopoietic cell lineage and that the germline was clonal, but subsequent empirical work has shown that chimerism may extend to many tissues, including the germline. To explore how natural selection on chimeric organisms should shape their social behavior, I construct an inclusive fitness model of sibling interactions that permits differing degrees of chimerism in the soma and germline. The model predicts that somatic chimerism should diminish sibling rivalry but that germline chimerism should typically intensify it. A further implication of the model is the possibility for intraorganismal conflict over developing phenotypes; as tissues may differ in their extent of chimerism-for example, placenta versus brain-their respective inclusive fitness may be maximized by different phenotypes. Communication between tissues in chimeric organisms might therefore be noisy, rapidly evolving, and fraught, as is common in systems with internal evolutionary conflicts of interest.}, }
@article {pmid33717435, year = {2021}, author = {Levin, SR and Grafen, A}, title = {Extending the range of additivity in using inclusive fitness.}, journal = {Ecology and evolution}, volume = {11}, number = {5}, pages = {1970-1983}, pmid = {33717435}, issn = {2045-7758}, abstract = {Inclusive fitness is a concept widely utilized by social biologists as the quantity organisms appear designed to maximize. However, inclusive fitness theory has long been criticized on the (uncontested) grounds that other quantities, such as offspring number, predict gene frequency changes accurately in a wider range of mathematical models. Here, we articulate a set of modeling assumptions that extend the range of scenarios in which inclusive fitness can be applied. We reanalyze recent formal analyses that searched for, but did not find, inclusive fitness maximization. We show (a) that previous models have not used Hamilton's definition of inclusive fitness, (b) a reinterpretation of Hamilton's definition that makes it usable in this context, and (c) that under the assumption of probabilistic mixing of phenotypes, inclusive fitness is indeed maximized in these models. We also show how to understand mathematically, and at an individual level, the definition of inclusive fitness, in an explicit population genetic model in which exact additivity is not assumed. We hope that in articulating these modeling assumptions and providing formal support for inclusive fitness maximization, we help bridge the gap between empiricists and theoreticians, which in some ways has been widening, demonstrating to mathematicians why biologists are content to use inclusive fitness, and offering one way to utilize inclusive fitness in general models of social behavior.}, }
@article {pmid33678027, year = {2021}, author = {Galimov, ER and Gems, D}, title = {Death happy: adaptive ageing and its evolution by kin selection in organisms with colonial ecology.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {376}, number = {1823}, pages = {20190730}, pmid = {33678027}, issn = {1471-2970}, support = {/WT_/Wellcome Trust/United Kingdom ; 215574/Z/19/Z/WT_/Wellcome Trust/United Kingdom ; 098565/Z/12/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {*Adaptation, Biological ; *Aging ; Animals ; Biological Coevolution ; *Biological Evolution ; Caenorhabditis elegans/*physiology ; Fishes/*physiology ; Life History Traits ; *Selection, Genetic ; }, abstract = {Standard evolutionary theory, supported by mathematical modelling of outbred, dispersed populations predicts that ageing is not an adaptation. We recently argued that in clonal, viscous populations, programmed organismal death could promote fitness through social benefits and has, in some organisms (e.g. Caenorhabditis elegans), evolved to shorten lifespan. Here, we review previous adaptive death theory, including consumer sacrifice, biomass sacrifice and defensive sacrifice types of altruistic adaptive death. In addition, we discuss possible adaptive death in certain semelparous fish, coevolution of reproductive and adaptive death, and adaptive reproductive senescence in C. elegans. We also describe findings from recent tests for the existence of adaptive death in C. elegans using computer modelling. Such models have provided new insights into how trade-offs between fitness at the individual and colony levels mean that senescent changes can be selected traits. Exploring further the relationship between adaptive death and social interactions, we consider examples where adaptive death results more from action of kin than from self-destructive mechanisms and, to describe this, introduce the term adaptive killing of kin. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'}, }
@article {pmid33678025, year = {2021}, author = {Heinze, J and Giehr, J}, title = {The plasticity of lifespan in social insects.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {376}, number = {1823}, pages = {20190734}, pmid = {33678025}, issn = {1471-2970}, mesh = {Animals ; Ants/*physiology ; Bees/*physiology ; Fertility ; Genetic Fitness ; *Life History Traits ; Longevity ; }, abstract = {One of the central questions of ageing research is why lifespans of organisms differ so tremendously among related taxa and, even more surprising, among members of the same species. Social insects provide a particularly pronounced example for this. Here, we review previously published information on lifespan plasticity in social insects and provide new data on worker lifespan in the ant Cardiocondyla obscurior, which because of its relatively short lifespan is a convenient model to study ageing. We show that individual lifespan may vary within species with several reproductive and social traits, such as egg-laying rate, queen number, task, colony size and colony composition. For example, in Cardiocondyla, highly fecund queens live longer than reproductively less active queens, and workers tend to live longer when transferred into a novel social environment or, as we show with new data, into small colonies. We hypothesize that this plasticity of lifespan serves to maximize the reproductive output of the colony as a whole and thus the inclusive fitness of all individuals. The underlying mechanisms that link the social environment or reproductive status with lifespan are currently unresolved. Several studies in honeybees and ants indicate an involvement of nutrient-sensing pathways, but the details appear to differ among species. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'}, }
@article {pmid33667486, year = {2021}, author = {Wu, R and Wu, X and Li, S and Li, G and Jiang, Z and Zhong, H and Wang, B and Yang, S and Wei, W}, title = {Predator odor exposure increases social contact in adolescents and parental behavior in adulthood in Brandt's voles.}, journal = {Behavioural processes}, volume = {186}, number = {}, pages = {104372}, doi = {10.1016/j.beproc.2021.104372}, pmid = {33667486}, issn = {1872-8308}, mesh = {Animals ; *Arvicolinae ; Behavior, Animal ; Female ; Male ; *Odorants ; Rabbits ; Social Behavior ; Weaning ; }, abstract = {Research suggests that predation risk during adolescence can program adult stress response and emotional behavior; however, little is known about the short-term and lasting residual effects of this experience on social behavior. We explored this concept in social Brandt's voles (Lasiopodomys brandtii). Adolescent male and female voles were exposed to distilled water, rabbit urine (as a non-predator stimulus), and cat urine for 60 min daily from postnatal day (PND) 28-49. Social play tests were conducted immediately following exposure on PND 28, 35, 42, and 49. In the social play test, repeated cat odor (CO) exposure enhanced the contact behavior of voles with their cagemate. Adolescent exposure to CO did not affect behavioral responses toward unrelated pups in the alloparental behavior test or same-sex individuals in the social interaction test. However, exposure to CO significantly enhanced the licking/grooming behavior of voles towards their own pups in the home cage parental behavior test. Repeated CO exposure significantly inhibited weight gain in male voles during adolescence. This effect was transmitted to the next generation, with lower weight gain in offspring before weaning. Following repeated CO exposure, males tended to have more female offspring whereas females produced more offspring, suggesting an adaptive strategy to increase inclusive fitness under predatory risk. These findings demonstrate that adolescent exposure to predatory risk augments adolescent social contact and adult parental behavior and suggest a role for improved inclusive fitness in mediating long-term outcomes.}, }
@article {pmid33589803, year = {2021}, author = {Kennedy, P and Sumner, S and Botha, P and Welton, NJ and Higginson, AD and Radford, AN}, title = {Diminishing returns drive altruists to help extended family.}, journal = {Nature ecology &amp; evolution}, volume = {5}, number = {4}, pages = {468-479}, pmid = {33589803}, issn = {2397-334X}, support = {G0802413/MRC_/Medical Research Council/United Kingdom ; 682253/ERC_/European Research Council/International ; }, mesh = {*Altruism ; Animals ; Family ; Humans ; Social Interaction ; *Wasps ; }, abstract = {Altruism between close relatives can be easily explained. However, paradoxes arise when organisms divert altruism towards more distantly related recipients. In some social insects, workers drift extensively between colonies and help raise less related foreign brood, seemingly reducing inclusive fitness. Since being highlighted by W. D. Hamilton, three hypotheses (bet hedging, indirect reciprocity and diminishing returns to cooperation) have been proposed for this surprising behaviour. Here, using inclusive fitness theory, we show that bet hedging and indirect reciprocity could only drive cooperative drifting under improbable conditions. However, diminishing returns to cooperation create a simple context in which sharing workers is adaptive. Using a longitudinal dataset comprising over a quarter of a million nest cell observations, we quantify cooperative payoffs in the Neotropical wasp Polistes canadensis, for which drifting occurs at high levels. As the worker-to-brood ratio rises in a worker's home colony, the predicted marginal benefit of a worker for expected colony productivity diminishes. Helping related colonies can allow effort to be focused on related brood that are more in need of care. Finally, we use simulations to show that cooperative drifting evolves under diminishing returns when dispersal is local, allowing altruists to focus their efforts on related recipients. Our results indicate the power of nonlinear fitness effects to shape social organization, and suggest that models of eusocial evolution should be extended to include neglected social interactions within colony networks.}, }
@article {pmid33583398, year = {2021}, author = {Wang, L and Cornell, SJ and Speed, MP and Arbuckle, K}, title = {Coevolution of group-living and aposematism in caterpillars: warning colouration may facilitate the evolution from group-living to solitary habits.}, journal = {BMC ecology and evolution}, volume = {21}, number = {1}, pages = {25}, pmid = {33583398}, issn = {2730-7182}, mesh = {Animals ; Biological Evolution ; *Biological Mimicry ; Habits ; Larva ; Phylogeny ; *Predatory Behavior ; }, abstract = {BACKGROUND: Animals use diverse antipredator mechanisms, including visual signalling of aversive chemical defence (aposematism). However, the initial evolution of aposematism poses the problem that the first aposematic individuals are conspicuous to predators who have not learned the significance of the warning colouration. In one scenario, aposematism evolves in group-living species and originally persisted due to kin selection or positive frequency-dependent selection in groups. Alternatively, group-living might evolve after aposematism because grouping can amplify the warning signal. However, our current understanding of the evolutionary dynamics of these traits is limited, leaving the relative merit of these scenarios unresolved.<br><br>RESULTS: We used a phylogenetic comparative approach to estimate phenotypic evolutionary models to enable inferences regarding ancestral states and trait dynamics of grouping and aposematic colouration in a classic model system (caterpillars). We find strong support for aposematism at the root of the clade, and some (but weaker) support for ancestral solitary habits. Transition rates between aposematism and crypsis are generally higher than those between group-living and solitary-living, suggesting that colouration is more evolutionarily labile than aggregation. We also find that the transition from group-living to solitary-living states can only happen in aposematic lineage, suggesting that aposematism facilitates the evolution of solitary caterpillars, perhaps due to the additional protection offered when the benefits of grouping are lost. We also find that the high frequency of solitary, cryptic caterpillars is because this state is particularly stable, in that the transition rates moving towards this state are substantially higher than those moving away from it, favouring its accumulation in the clade over evolutionary time.<br><br>CONCLUSIONS: Our results provide new insights into the coevolution of colour and aggregation in caterpillars. We find support for an aposematic caterpillar at the root of this major clade, and for the signal augmentation hypothesis as an explanation of the evolution of aposematic, group-living caterpillars. We find that colouration is more labile than aggregation behaviour, but that the combination of solitary and cryptic habits is particularly stable. Finally, our results reveal that the transitions from group-living to solitary-living could be facilitated by aposematism, providing a new link between these well-studied traits.}, }
@article {pmid33563093, year = {2021}, author = {Barragan-Jason, G and Cauchoix, M and Regnier, A and Bourjade, M and Hopfensitz, A and Chaine, AS}, title = {Schoolchildren cooperate more successfully with non-kin than with siblings.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1944}, pages = {20202951}, pmid = {33563093}, issn = {1471-2954}, mesh = {Adult ; Child ; Child, Preschool ; Cooperative Behavior ; Friends ; Humans ; *Interpersonal Relations ; *Siblings ; Social Networking ; }, abstract = {Cooperation plays a key role in the development of advanced societies and can be stabilized through shared genes (kinship) or reciprocation. In humans, cooperation among kin occurs more readily than cooperation among non-kin. In many organisms, cooperation can shift with age (e.g. helpers at the nest); however, little is known about developmental shifts between kin and non-kin cooperation in humans. Using a cooperative game, we show that 3- to 10-year-old French schoolchildren cooperated less successfully with siblings than with non-kin children, whether or not non-kin partners were friends. Furthermore, children with larger social networks cooperated better and the perception of friendship among non-friends improved after cooperating. These results contrast with the well-established preference for kin cooperation among adults and indicate that non-kin cooperation in humans might serve to forge and extend non-kin social relationships during middle childhood and create opportunities for future collaboration beyond kin. Our results suggest that the current view of cooperation in humans may only apply to adults and that future studies should focus on how and why cooperation with different classes of partners might change during development in humans across cultures as well as other long-lived organisms.}, }
@article {pmid33526674, year = {2021}, author = {Simonet, C and McNally, L}, title = {Kin selection explains the evolution of cooperation in the gut microbiota.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {6}, pages = {}, pmid = {33526674}, issn = {1091-6490}, mesh = {Bacteria/classification/*genetics/growth &amp; development ; Ecosystem ; *Evolution, Molecular ; Gastrointestinal Microbiome/*genetics ; Genetic Fitness/genetics ; Genome, Bacterial/genetics ; Humans ; Microbiota/*genetics ; Phylogeny ; Reproduction/genetics ; Selection, Genetic/genetics ; }, abstract = {Through the secretion of "public goods" molecules, microbes cooperatively exploit their habitat. This is known as a major driver of the functioning of microbial communities, including in human disease. Understanding why microbial species cooperate is therefore crucial to achieve successful microbial community management, such as microbiome manipulation. A leading explanation is that of Hamilton's inclusive-fitness framework. A cooperator can indirectly transmit its genes by helping the reproduction of an individual carrying similar genes. Therefore, all else being equal, as relatedness among individuals increases, so should cooperation. However, the predictive power of relatedness, particularly in microbes, is surrounded by controversy. Using phylogenetic comparative analyses across the full diversity of the human gut microbiota and six forms of cooperation, we find that relatedness is predictive of the cooperative gene content evolution in gut-microbe genomes. Hence, relatedness is predictive of cooperation over broad microbial taxonomic levels that encompass variation in other life-history and ecology details. This supports the generality of Hamilton's central insights and the relevance of relatedness as a key parameter of interest to advance microbial predictive and engineering science.}, }
@article {pmid33523789, year = {2021}, author = {Kennedy, P and Radford, AN}, title = {Kin Blackmail as a Coercive Route to Altruism.}, journal = {The American naturalist}, volume = {197}, number = {2}, pages = {266-273}, doi = {10.1086/712349}, pmid = {33523789}, issn = {1537-5323}, mesh = {*Altruism ; Animals ; *Behavior, Animal ; *Coercion ; Genetic Fitness ; Social Behavior ; }, abstract = {AbstractThe evolution of altruism (helping a recipient at personal cost) often involves conflicts of interest. Recipients frequently prefer greater altruism than actors are prepared to provide. Coercion by recipients normally involves limiting an actor's options. Here, we consider the possibility of a coercive recipient limiting its own options. Forty years ago, Amotz Zahavi suggested that nesting birds may be "blackmailed" into increased parental care if offspring threaten to harm themselves (and therefore jeopardize the direct fitness of their parents). In a simple kin selection model, we expand blackmail to indirect fitness and highlight that blackmail can occur between any kin to drive reproductive division of labor. In principle, a recipient may place its own fitness at risk (brinkmanship), imposing sanctions on a relative's indirect fitness if the relative fails to cooperate. To use its own survival or reproduction as leverage in a sequential game, a recipient must increase the extent to which its existing fitness depends on the actor's behavior and therefore credibly commit to a cost if the actor does not comply. As it requires opportunities for commitment, kin blackmail can arise only under stringent conditions, but existing kin blackmailers may pass unnoticed because of their strategic success.}, }
@article {pmid33522615, year = {2021}, author = {Anten, NPR and Chen, BJW}, title = {Detect thy family: Mechanisms, ecology and agricultural aspects of kin recognition in plants.}, journal = {Plant, cell &amp; environment}, volume = {44}, number = {4}, pages = {1059-1071}, pmid = {33522615}, issn = {1365-3040}, mesh = {Communication ; *Crop Production ; *Ecology ; Plant Physiological Phenomena ; Plant Roots/physiology ; Plants/*metabolism ; }, abstract = {The phenomenon that organisms can distinguish genetically related individuals from strangers (i.e., kin recognition) and exhibit more cooperative behaviours towards their relatives (i.e., positive kin discrimination) has been documented in a wide variety of organisms. However, its occurrence in plants has been considered only recently. Despite the concerns about some methodologies used to document kin recognition, there is sufficient evidence to state that it exists in plants. Effects of kin recognition go well beyond reducing resource competition between related plants and involve interactions with symbionts (e.g., mycorrhizal networks). Kin recognition thus likely has important implications for evolution of plant traits, diversity of plant populations, ecological networks and community structures. Moreover, as kin selection may result in less competitive traits and thus greater population performance, it holds potential promise for crop breeding. Exploration of these evo-ecological and agricultural implications requires adequate control and measurements of relatedness, sufficient replication at genotypic level and comprehensive measurements of performance/fitness effects of kin discrimination. The primary questions that need to be answered are: when, where and by how much positive kin discrimination improves population performance.}, }
@article {pmid33508326, year = {2021}, author = {Avila, P and Priklopil, T and Lehmann, L}, title = {Hamilton's rule, gradual evolution, and the optimal (feedback) control of phenotypically plastic traits.}, journal = {Journal of theoretical biology}, volume = {526}, number = {}, pages = {110602}, doi = {10.1016/j.jtbi.2021.110602}, pmid = {33508326}, issn = {1095-8541}, mesh = {*Biological Evolution ; Feedback ; Game Theory ; Humans ; Phenotype ; *Selection, Genetic ; }, abstract = {Most traits expressed by organisms, such as gene expression profiles, developmental trajectories, behavioural sequences and reaction norms are function-valued traits (colloquially "phenotypically plastic traits"), since they vary across an individual's age and in response to various internal and/or external factors (state variables). Furthermore, most organisms live in populations subject to limited genetic mixing and are thus likely to interact with their relatives. We here formalise selection on genetically determined function-valued traits of individuals interacting in a group-structured population, by deriving the marginal version of Hamilton's rule for function-valued traits. This rule simultaneously gives a condition for the invasion of an initially rare mutant function-valued trait and its ultimate fixation in the population (invasion thus implies substitution). Hamilton's rule thus underlies the gradual evolution of function-valued traits and gives rise to necessary first-order conditions for their uninvadability (evolutionary stability). We develop a novel analysis using optimal control theory and differential game theory, to simultaneously characterise and compare the first-order conditions of (i) open-loop traits - functions of time (or age) only, and (ii) closed-loop (state-feedback) traits - functions of both time and state variables. We show that closed-loop traits can be represented as the simpler open-loop traits when individuals do not interact or when they interact with clonal relatives. Our analysis delineates the role of state-dependence and interdependence between individuals for trait evolution, which has implications to both life-history theory and social evolution.}, }
@article {pmid33491804, year = {2021}, author = {Correia, HE and Abebe, A and Dobson, FS}, title = {Multiple paternity and the number of offspring: A model reveals two major groups of species.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {43}, number = {4}, pages = {e2000247}, doi = {10.1002/bies.202000247}, pmid = {33491804}, issn = {1521-1878}, mesh = {Animals ; Bayes Theorem ; Mammals ; *Microsatellite Repeats/genetics ; *Paternity ; Reproduction ; Sexual Behavior, Animal ; }, abstract = {Parentage analyses via microsatellite markers have revealed multiple paternity within the broods of polytocous species of mammals, reptiles, amphibians, fishes and invertebrates. The widespread phenomenon of multiple paternity may have attending relationships with such evolutionary processes as sexual selection and kin selection. However, just how much multiple paternity should a species exhibit? We developed Bayesian null models of how multiple paternity relates to brood sizes. For each of 114 species with published data on brood sizes and numbers of sires, we compared our null model estimates to published frequencies of multiple paternity. The majority of species fell close to our null model, especially among fish and invertebrate species. Some species, however, had low probabilities of multiple paternity, far from the predictions of the null model, likely due to sexual selection and environmental constraints. We suggest a major division among species' mating systems between those with close to random mating and high levels of multiple paternity, and those with constraints that produce low levels of multiple paternity.}, }
@article {pmid33459427, year = {2021}, author = {Rueger, T and Buston, PM and Bogdanowicz, SM and Wong, MY}, title = {Genetic relatedness in social groups of the emerald coral goby Paragobiodon xanthosoma creates potential for weak kin selection.}, journal = {Molecular ecology}, volume = {30}, number = {5}, pages = {1311-1321}, doi = {10.1111/mec.15809}, pmid = {33459427}, issn = {1365-294X}, mesh = {Animals ; *Anthozoa ; Microsatellite Repeats/genetics ; Papua New Guinea ; *Perciformes/genetics ; Selection, Genetic ; Social Behavior ; *Xanthosoma ; }, abstract = {Animals forming social groups that include breeders and nonbreeders present evolutionary paradoxes; why do breeders tolerate nonbreeders? And why do nonbreeders tolerate their situation? Both paradoxes are often explained with kin selection. Kin selection is, however, assumed to play little or no role in social group formation of marine organisms with dispersive larval phases. Yet, in some marine organisms, recent evidence suggests small-scale patterns of relatedness, meaning that this assumption must always be tested. Here, we investigated the genetic relatedness of social groups of the emerald coral goby, Paragobiodon xanthosoma. We genotyped 73 individuals from 16 groups in Kimbe Bay, Papua New Guinea, at 20 microsatellite loci and estimated pairwise relatedness among all individuals. We found that estimated pairwise relatedness among individuals within groups was significantly higher than the pairwise relatedness among individuals from the same reef, and pairwise relatedness among individuals from the same reef was significantly higher than the pairwise relatedness among individuals from different reefs. This spatial signature suggests that there may be very limited dispersal in this species. The slightly positive relatedness within groups creates the potential for weak kin selection, which may help to resolve the paradox of why breeders tolerate subordinates in P. xanthosoma. The other paradox, why nonbreeders tolerate their situation, is better explained by alternative hypotheses such as territory inheritance, and ecological and social constraints. We show that even in marine animals with dispersive larval phases, kin selection needs to be considered to explain the evolution of complex social groups.}, }
@article {pmid33457190, year = {2020}, author = {Seitz, BM and Polack, CW and Miller, RR}, title = {Adaptive Memory: Generality of the Parent Processing Effect and Effects of Biological Relatedness on Recall.}, journal = {Evolutionary psychological science}, volume = {6}, number = {3}, pages = {246-260}, pmid = {33457190}, issn = {2198-9885}, support = {R01 MH033881/MH/NIMH NIH HHS/United States ; }, abstract = {The adaptive memory framework posits that human memory is an evolved cognitive feature, in which stimuli relevant to fitness are better remembered than neutral stimuli. There is now substantial evidence that processing a neutral stimulus in terms of its relevancy to an imagined ancestral survival scenario enhances recall, although there is still disagreement concerning the proximate mechanisms responsible for this effect. Several other mnemonic biases have recently been discovered that similarly appear to reflect evolutionary pressures, including a bias to remember items relevant to an imagined parenting scenario. We tested the generality of this parent processing effect by varying the biological relatedness of the imagined child. We also varied the biological relatedness of a child during an imagined third-person survival processing scenario. Across four experiments, we found evidence that simply altering the described biological relatedness of a child in the parenting scenario and third-person survival processing scenario can affect recall, such that items are better remembered when made relevant to a biological child compared to an adopted child. How these findings inform the general adaptive memory framework is discussed.}, }
@article {pmid33411951, year = {2021}, author = {Gutiérrez, EG and Vivas-Toro, I and Carmona-Ruíz, D and Villalobos-Chaves, D and Rodríguez-Herrera, B and Real-Monroy, MD and León-Avila, G and Ortega, J}, title = {Socio-spatial organization reveals paternity and low kinship in the Honduran white bat (Ectophylla alba) in Costa Rica.}, journal = {Integrative zoology}, volume = {16}, number = {5}, pages = {646-658}, doi = {10.1111/1749-4877.12514}, pmid = {33411951}, issn = {1749-4877}, mesh = {Animals ; *Behavior, Animal ; Biological Evolution ; Chiroptera/*genetics/physiology ; Costa Rica ; Female ; Male ; *Paternity ; Social Behavior ; }, abstract = {Ectophylla alba is a tent-making bat that roosts in mixed-sex clusters comprising adults and offspring. Our goal was to determine the genetic identity of individuals belonging to different roosting groups. We tested the hypothesis of kin selection as a major force structuring group composition. We used 9 microsatellites designed for E. alba to determine the genetic identity and probability of parentage of individuals. We analyzed parentage and kinship using the software ML-Relate, GenAIEx, and Cervus. The obtained relationship probabilities (0.5) revealed a clear maternal relationship between female adults and offspring with allele compatibility, and at least 5 relationships between male adults and pups. We found a low degree of relatedness within roosting groups. Between roosting groups at different sites, the mean probability of a half-sibling relationship ranged from 0.214 to 0.244 and, for full-sibling relationship, from 0.383 to 0.553. Genetically, adult individuals were poorly related within clusters, and kinship as an evolutionary force could not explain group membership.}, }
@article {pmid33338428, year = {2021}, author = {Siracusa, ER and Boutin, S and Dantzer, B and Lane, JE and Coltman, DW and McAdam, AG}, title = {Familiar Neighbors, but Not Relatives, Enhance Fitness in a Territorial Mammal.}, journal = {Current biology : CB}, volume = {31}, number = {2}, pages = {438-445.e3}, doi = {10.1016/j.cub.2020.10.072}, pmid = {33338428}, issn = {1879-0445}, mesh = {Animals ; *Evolution, Molecular ; Female ; *Genetic Fitness ; Homing Behavior ; Male ; Sciuridae/*physiology ; *Social Behavior ; }, abstract = {One of the outstanding questions in evolutionary biology is the extent to which mutually beneficial interactions and kin selection can facilitate the evolution of cooperation by mitigating conflict between interacting organisms. The indirect fitness benefits gained from associating with kin are an important pathway to conflict resolution,[1] but conflict can also be resolved if individuals gain direct benefits from cooperating with one another (e.g., mutualism or reciprocity).[2] Because of the kin-structured nature of many animal societies, it has been difficult for previous research to assess the relative importance of these mechanisms.[3-5] However, one area that might allow for the relative roles of kin selection and mutualistic benefits to be disentangled is in the resolution of conflict over territorial space.[6] Although much research has focused on group-living species, the question of how cooperation can first be favored in solitary, territorial species remains a key question. Using 22 years of data from a population of North American red squirrels, we assessed how kinship and familiarity with neighbors affected fitness in a territorial mammal. Although living near kin did not enhance fitness, familiarity with neighbors increased survival and annual reproductive success. These fitness benefits were strong enough to compensate for the effects of aging later in life and have potential consequences for the evolution of senescence. We suggest that such substantial fitness benefits provide the opportunity for the evolution of cooperation between adversarial neighbors, offering insight into the role that mutually beneficial behaviors might play in facilitating and stabilizing social systems.}, }
@article {pmid33326651, year = {2021}, author = {Galbraith, DA and Ma, R and Grozinger, CM}, title = {Tissue-specific transcription patterns support the kinship theory of intragenomic conflict in honey bees (Apis mellifera).}, journal = {Molecular ecology}, volume = {30}, number = {4}, pages = {1029-1041}, doi = {10.1111/mec.15778}, pmid = {33326651}, issn = {1365-294X}, mesh = {Animals ; Bees/genetics ; Brain ; Gene Expression ; *Gene Regulatory Networks ; *Reproduction ; }, abstract = {Kin selection may act differently on genes inherited from parents (matrigenes and patrigenes), resulting in intragenomic conflict. This conflict can be observed as differential expression of matrigenes and patrigenes, or parent-specific gene expression (PSGE). In honey bees (Apis mellifera), intragenomic conflict is hypothesized to occur in multiple social contexts. Previously, we found that patrigene-biased expression in reproductive tissues was associated with increased reproductive potential in worker honey bees, consistent with the prediction that patrigenes are selected to promote selfish behaviour in this context. Here, we examined brain gene expression patterns to determine if PSGE is also found in other tissues. As before, the number of transcripts showing patrigene expression bias was significantly greater in the brains of reproductive vs. sterile workers, while the number of matrigene-biased transcripts was not significantly different. Twelve transcripts out of the 374 showing PSGE in either tissue showed PSGE in both brain and reproductive tissues; this overlap was significantly greater than expected by chance. However, the majority of transcripts show PSGE only in one tissue, suggesting the epigenetic mechanisms mediating PSGE exhibit plasticity between tissues. There was no significant overlap between transcripts that showed PSGE and transcripts that were significantly differentially expressed. Weighted gene correlation network analysis identified modules which were significantly enriched in both types of transcripts, suggesting that these genes may influence each other through gene networks. Our results provide further support for the kin selection theory of intragenomic conflict, and provide valuable insights into the mechanisms which may mediate this process.}, }
@article {pmid33318799, year = {2020}, author = {Arnot, M and Brandl, E and Campbell, OLK and Chen, Y and Du, J and Dyble, M and Emmott, EH and Ge, E and Kretschmer, LDW and Mace, R and Micheletti, AJC and Nila, S and Peacey, S and Salali, GD and Zhang, H}, title = {How evolutionary behavioural sciences can help us understand behaviour in a pandemic.}, journal = {Evolution, medicine, and public health}, volume = {2020}, number = {1}, pages = {264-278}, pmid = {33318799}, issn = {2050-6201}, abstract = {The COVID-19 pandemic has brought science into the public eye and to the attention of governments more than ever before. Much of this attention is on work in epidemiology, virology and public health, with most behavioural advice in public health focusing squarely on 'proximate' determinants of behaviour. While epidemiological models are powerful tools to predict the spread of disease when human behaviour is stable, most do not incorporate behavioural change. The evolutionary basis of our preferences and the cultural evolutionary dynamics of our beliefs drive behavioural change, so understanding these evolutionary processes can help inform individual and government decision-making in the face of a pandemic. Lay summary: The COVID-19 pandemic has brought behavioural sciences into the public eye: Without vaccinations, stopping the spread of the virus must rely on behaviour change by limiting contact between people. On the face of it, "stop seeing people" sounds simple. In practice, this is hard. Here we outline how an evolutionary perspective on behaviour change can provide additional insights. Evolutionary theory postulates that our psychology and behaviour did not evolve to maximize our health or that of others. Instead, individuals are expected to act to maximise their inclusive fitness (i.e, spreading our genes) - which can lead to a conflict between behaviours that are in the best interests for the individual, and behaviours that stop the spread of the virus. By examining the ultimate explanations of behaviour related to pandemic-management (such as behavioural compliance and social distancing), we conclude that "good of the group" arguments and "one size fits all" policies are unlikely to encourage behaviour change over the long-term. Sustained behaviour change to keep pandemics at bay is much more likely to emerge from environmental change, so governments and policy makers may need to facilitate significant social change - such as improving life experiences for disadvantaged groups.}, }
@article {pmid37588542, year = {2021}, author = {Gehrig, S and Mesoudi, A and Lamba, S}, title = {Banking on cooperation: an evolutionary analysis of microfinance loan repayment behaviour.}, journal = {Evolutionary human sciences}, volume = {3}, number = {}, pages = {e2}, pmid = {37588542}, issn = {2513-843X}, abstract = {Microfinance is an economic development tool that provides loans to low-income borrowers to stimulate economic growth and reduce financial hardship. Lenders typically require joint liability, where multiple borrowers share the responsibility of repaying a group loan. We propose that this lending practice creates a cooperation dilemma similar to that faced by humans and other organisms in nature across many domains. This could offer a real-world test case for evolutionary theories of cooperation from the biological sciences. In turn, such theories could provide new insights into loan repayment behaviour. We first hypothesise how group loan repayment efficacy should be affected by mechanisms of assortment from the evolutionary literature on cooperation, i.e. common ancestry (kin selection), prior interaction (reciprocity), partner choice, similarity of tags, social learning, and ecology and demography. We then assess selected hypotheses by reviewing 41 studies from 32 countries on micro-borrowers' loan repayment, evaluating which characteristics of borrowers are associated with credit repayment behaviour. Surprisingly, we find that kinship is mostly negatively associated with repayment efficacy, but prior interaction and partner choice are both more positively associated. Our work highlights the scope of evolutionary theory to provide systematic insight into how humans respond to novel economic institutions and interventions.}, }
@article {pmid33283689, year = {2021}, author = {Tanskanen, AO and Danielsbacka, M}, title = {Grandmaternal investment and early childhood injury: the role of X-chromosomal relatedness.}, journal = {Journal of biosocial science}, volume = {53}, number = {6}, pages = {968-971}, doi = {10.1017/S0021932020000711}, pmid = {33283689}, issn = {1469-7599}, mesh = {Biological Evolution ; Child ; Child, Preschool ; Cohort Studies ; Family ; *Grandparents ; Humans ; Infant ; }, abstract = {Evolutionary theory posits that grandmothers can increase their inclusive fitness by investing time and resources in their grandchildren. According on the X-linked grandmother hypothesis, the asymmetric inheritance of X-chromosomes should be responsible for the biased effect of the investment by maternal and paternal grandmothers towards granddaughters and grandsons. The British Millennium Cohort Study (n=4445 children) was used to investigate the association between grandmaternal childcare and children's injuries between the ages of 9 months and 3 years. Support was found for the X-linked grandmother hypothesis predicting that the investment of paternal grandmothers benefits more granddaughters than grandsons, the investment of paternal grandmothers benefits granddaughters more than the investment of maternal grandmothers, and the investment of maternal grandmothers is similarly associated with the injuries of granddaughters and grandsons. However, no support was found for the prediction that maternal grandmothers benefit more grandsons than paternal grandmothers. Thus, some, although not univocal, evidence for the prediction that X-chromosomal relatedness shapes the grandmaternal effect on child outcomes was found.}, }
@article {pmid33253458, year = {2021}, author = {Ndhlovu, A and Durand, PM and Ramsey, G}, title = {Programmed cell death as a black queen in microbial communities.}, journal = {Molecular ecology}, volume = {30}, number = {5}, pages = {1110-1119}, doi = {10.1111/mec.15757}, pmid = {33253458}, issn = {1365-294X}, mesh = {*Apoptosis ; *Microbiota/genetics ; }, abstract = {Programmed cell death (PCD) in unicellular organisms is in some instances an altruistic trait. When the beneficiaries are clones or close kin, kin selection theory may be used to explain the evolution of the trait, and when the trait evolves in groups of distantly related individuals, group or multilevel selection theory is invoked. In mixed microbial communities, the benefits are also available to unrelated taxa. But the evolutionary ecology of PCD in communities is poorly understood. Few hypotheses have been offered concerning the community role of PCD despite its far-reaching effects. The hypothesis we consider here is that PCD is a black queen. The Black Queen Hypothesis (BQH) outlines how public goods arising from a leaky function are exploited by other taxa in the community. Black Queen (BQ) traits are essential for community survival, but only some members bear the cost of possessing them, while others lose the trait In addition, BQ traits have been defined in terms of adaptive gene loss, and it is unknown whether this has occurred for PCD. Our conclusion is that PCD fulfils the two most important criteria of a BQ (leakiness and costliness), but that more empirical data are needed for assessing the remaining two criteria. In addition, we hold that for viewing PCD as a BQ, the original BQH needs to include social traits. Thus, despite some empirical and conceptual shortcomings, the BQH provides a helpful avenue for investigating PCD in microbial communities.}, }
@article {pmid33238064, year = {2021}, author = {Rodrigues, AMM and Estrela, S and Brown, SP}, title = {Community lifespan, niche expansion and the evolution of interspecific cooperation.}, journal = {Journal of evolutionary biology}, volume = {34}, number = {2}, pages = {352-363}, doi = {10.1111/jeb.13739}, pmid = {33238064}, issn = {1420-9101}, mesh = {*Biological Evolution ; *Ecosystem ; *Models, Genetic ; Symbiosis/*genetics ; }, abstract = {Microbes live in dense and diverse communities where they deploy many traits that promote the growth and survival of neighbouring species, all the while also competing for shared resources. Because microbial communities are highly dynamic, the costs and benefits of species interactions change over the growth cycle of a community. How mutualistic interactions evolve under such demographic and ecological conditions is still poorly understood. Here, we develop an eco-evolutionary model to explore how different forms of helping with distinct fitness effects (rate-enhancing and yield-enhancing) affect the multiple phases of community growth, and its consequences for the evolution of mutualisms. We specifically focus on a form of yield-enhancing trait in which cooperation augments the common pool of resources, termed niche expansion. We show that although mutualisms in which cooperation increases partners growth rate are generally favoured at early stages of community growth, niche expansion can evolve at later stages where densities are high. Further, we find that niche expansion can promote the evolution of reproductive restraint, in which a focal species adaptively reduces its own growth rate to increase the density of partner species. Our findings suggest that yield-enhancing mutualisms are more prevalent in stable habitats with a constant supply of resources, and where populations typically live at high densities. In general, our findings highlight the need to integrate different components of population growth in the analysis of mutualisms to understand the composition and function of microbial communities.}, }
@article {pmid33179250, year = {2020}, author = {Benler, S and Koonin, EV}, title = {Phage lysis-lysogeny switches and programmed cell death: Danse macabre.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {42}, number = {12}, pages = {e2000114}, doi = {10.1002/bies.202000114}, pmid = {33179250}, issn = {1521-1878}, mesh = {Apoptosis ; Bacteriophage lambda/genetics ; *Bacteriophages/genetics ; Clustered Regularly Interspaced Short Palindromic Repeats ; *Lysogeny ; Virus Latency ; }, abstract = {Exploration of immune systems in prokaryotes, such as restriction-modification or CRISPR-Cas, shows that both innate and adaptive systems possess programmed cell death (PCD) potential. The key outstanding question is how the immune systems sense and "predict" infection outcomes to "decide" whether to fight the pathogen or induce PCD. There is a striking parallel between this life-or-death decision faced by the cell and the decision by temperate viruses to protect or kill their hosts, epitomized by the lysis-lysogeny switch of bacteriophage Lambda. Immune systems and temperate phages sense the same molecular inputs, primarily, DNA damage, that determine whether the cell lives or dies. Because temperate (pro)phages are themselves components of prokaryotic genomes, their shared "interests" with the hosts result in coregulation of the lysis-lysogeny switch and immune systems that jointly provide the cell with the decision machinery to probe and predict infection outcomes, answering the life-or-death question.}, }
@article {pmid33158025, year = {2020}, author = {Lecocq de Pletincx, N and Aron, S}, title = {Sociogenetic Organization of the Red Honey Ant (Melophorus bagoti).}, journal = {Insects}, volume = {11}, number = {11}, pages = {}, pmid = {33158025}, issn = {2075-4450}, support = {J.0151.16 and T.0140.18//Fonds De La Recherche Scientifique - FNRS/ ; }, abstract = {Kin selection and inclusive fitness are thought to be key factors explaining the reproductive altruism displayed by workers in eusocial insect species. However, when a colony's queen has mated with <2 males, workers may increase their fitness by producing their own male offspring. Conversely, when the queen has mated with ≥2 males, workers are expected to increase their inclusive fitness by eschewing the production of their sons and preventing other workers from reproducing as well. Here, we investigated sociogenetic structure and worker reproduction in the red honey ant, Melophorus bagoti. Morphometric analyses revealed that workers belong to one of two distinct subcastes: they are either majors or minors. Using DNA microsatellite markers, we showed that all the colonies had a single, multiple-mated queen and that there was no relationship between worker patriline and worker subcaste. Furthermore, we found that workers were producing males in the presence of the queen, which contrasts with the predictions of inclusive fitness theory. Although our results are based on a small sample, they can serve as the foundation for future research examining worker reproduction in M. bagoti.}, }
@article {pmid33144958, year = {2020}, author = {Vitt, S and Hiller, J and Thünken, T}, title = {Intrasexual selection: Kin competition increases male-male territorial aggression in a monogamous cichlid fish.}, journal = {Ecology and evolution}, volume = {10}, number = {20}, pages = {11183-11191}, pmid = {33144958}, issn = {2045-7758}, abstract = {During intrasexual competition, individuals of the same sex compete for access to breeding sites and mating partners, often accompanied by aggressive behavior. Kin selection theory predicts different kin-directed social interactions ranging from cooperation to aggression depending on the context and the resource in question. Kin competition reducing indirect fitness might be avoided by actively expelling relatives from territories and by showing higher aggression against kin. The West-African cichlid Pelvicachromis taeniatus is a monogamous cave breeder with males occupying and defending breeding sites against rivals. This species is capable of kin recognition and shows kin-preference during juvenile shoaling and mate choice. However, subadults of P. taeniatus seem to avoid the proximity of same-sex kin. In the present study, we examined territorial aggression of territory holders against intruding related and unrelated males as well as intruder's behavior. We observed higher aggression among related competitors suggesting that related males are less tolerated as neighbors. Avoidance of intrasexual competition with relatives might increase indirect fitness of males in monogamous species.}, }
@article {pmid33139540, year = {2020}, author = {Kay, T and Keller, L and Lehmann, L}, title = {The evolution of altruism and the serial rediscovery of the role of relatedness.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {117}, number = {46}, pages = {28894-28898}, pmid = {33139540}, issn = {1091-6490}, mesh = {*Altruism ; Animals ; *Biological Evolution ; *Cooperative Behavior ; Humans ; Models, Genetic ; Selection, Genetic/genetics ; }, abstract = {The genetic evolution of altruism (i.e., a behavior resulting in a net reduction of the survival and/or reproduction of an actor to benefit a recipient) once perplexed biologists because it seemed paradoxical in a Darwinian world. More than half a century ago, W. D. Hamilton explained that when interacting individuals are genetically related, alleles for altruism can be favored by selection because they are carried by individuals more likely to interact with other individuals carrying the alleles for altruism than random individuals in the population ("kin selection"). In recent decades, a substantial number of supposedly alternative pathways to altruism have been published, leading to controversies surrounding explanations for the evolution of altruism. Here, we systematically review the 200 most impactful papers published on the evolution of altruism and identify 43 evolutionary models in which altruism evolves and where the authors attribute the evolution of altruism to a pathway other than kin selection and/or deny the role of relatedness. An analysis of these models reveals that in every case the life cycle assumptions entail local reproduction and local interactions, thereby leading to interacting individuals being genetically related. Thus, contrary to the authors' claims, Hamilton's relatedness drives the evolution to altruism in their models. The fact that several decades of investigating the evolution to altruism have resulted in the systematic and unwitting rediscovery of the same mechanism is testament to the fundamental importance of positive relatedness between actor and recipient for explaining the evolution of altruism.}, }
@article {pmid33114592, year = {2020}, author = {Schausberger, P and Sato, Y}, title = {Kin-Mediated Male Choice and Alternative Reproductive Tactics in Spider Mites.}, journal = {Biology}, volume = {9}, number = {11}, pages = {}, pmid = {33114592}, issn = {2079-7737}, support = {L18534//Japan Society for the Promotion of Science/ ; }, abstract = {Optimal outbreeding and kin selection theories state that the degree of kinship is a fundamental determinant in any mating system. However, the role of kinship in male choice and alternative reproductive tactics (ARTs) is poorly known. We assessed the influence of kinship on male choice and expression of ARTs in two populations of two-spotted spider mites Tetranychus urticae. Male spider mites guard premature females, which is an indicator of mate choice, and may conditionally adopt fighting or sneaking tactics to secure access to females. Males competing with kin or non-kin were offered one kin or non-kin female (experiment 1) and single males were presented a choice of kin and non-kin females (experiment 2). Under kin competition, males of both populations were more prone to guard non-kin than kin females at a 3:1 fighter:sneaker ratio. Under non-kin competition, all males were fighters. Under no-choice, males used novelty as indicator of genetic dissimilarity, serving as absolute decision rule for outbreeding. Under choice, comparative evaluation allowed males to preferentially guard females with higher reproductive potential. Overall, our study suggests that male spider mites can assess kinship of rivals and prospective mates. Kin discrimination allows adaptive, context-specific non-random mating preference and adjustment of ARTs.}, }
@article {pmid33078506, year = {2020}, author = {Gardner, A and Hardy, ICW}, title = {Adjustment of sex allocation to co-foundress number and kinship under local mate competition: An inclusive-fitness analysis.}, journal = {Journal of evolutionary biology}, volume = {33}, number = {12}, pages = {1806-1812}, pmid = {33078506}, issn = {1420-9101}, support = {771387/ERC_/European Research Council/International ; }, mesh = {Animals ; Biological Evolution ; Female ; *Inbreeding ; Male ; *Models, Genetic ; Ploidies ; *Sex Ratio ; *Sexual Behavior, Animal ; Wasps/*physiology ; }, abstract = {Hamilton's theory of local mate competition (LMC) describes how competition between male relatives for mating opportunities favours a female-biased parental investment. LMC theory has been extended in many ways to explore a range of genetic and life-history influences on sex allocation strategies, including showing that increasing genetic homogeneity within mating groups should favour greater female bias. However, there has been no quantitative theoretical prediction as to how females should facultatively adjust their sex allocation in response to co-foundress number and kinship. This shortfall has been highlighted recently by the finding that sex ratios produced by sub-social parasitoid wasps in the family Bethylidae are affected by the number of co-foundresses and by whether these are sisters or unrelated females. Here we close this gap in LMC theory by taking an inclusive-fitness approach to derive explicit theoretical predictions for this scenario. We find that, in line with the recent empirical results, females should adopt a more female-biased sex allocation when their co-foundresses are less numerous and are their sisters. Our model appears to predict somewhat more female bias than is observed empirically; we discuss a number of possible model extensions that would improve realism and that would be expected to result in a closer quantitative fit with experimental data.}, }
@article {pmid33064592, year = {2020}, author = {Madgwick, PG}, title = {Spite and the Geometry of Negative Relatedness.}, journal = {The American naturalist}, volume = {196}, number = {5}, pages = {E119-E126}, doi = {10.1086/710764}, pmid = {33064592}, issn = {1537-5323}, mesh = {Altruism ; Animals ; Behavior, Animal ; Competitive Behavior ; Cooperative Behavior ; *Genetic Fitness ; Models, Genetic ; Selection, Genetic ; *Social Behavior ; }, abstract = {AbstractSpite is the most surprising prediction of inclusive fitness theory because it suggests that a gene can be favored by natural selection despite causing harm to both the individuals that carry it and those around them. A gene for spite can only be favored because of negative relatedness, which means that the actor that carries the gene is less likely to share the gene for spite with the surrounding recipients than the random expectation. While positive relatedness can be simply reduced to the intuitive concept of kinship, negative relatedness is deeply counterintuitive. Here I clarify that negative relatedness is frequency dependent, and I identify a hidden assumption in its widely used formula. Accordingly, while the well-studied "lighter" side of inclusive fitness (with helping behaviors and positive relatedness) is dominated by traits that are favored under kin selection, I predict that the understudied "darker" side of inclusive fitness (with harming behaviors and negative relatedness) is dominated by traits that are favored under greenbeard/kind selection-and I discuss the existing evidence that tentatively supports this hypothesis.}, }
@article {pmid32979124, year = {2020}, author = {Revynthi, AM and van Pol, KE and Janssen, A and Egas, M}, title = {Males cannibalise and females disperse in the predatory mite Phytoseiulus persimilis.}, journal = {Experimental &amp; applied acarology}, volume = {82}, number = {2}, pages = {185-198}, doi = {10.1007/s10493-020-00552-9}, pmid = {32979124}, issn = {1572-9702}, support = {Green Innovation Cluster VP4//European Regional Development Fund/ ; }, mesh = {*Animal Distribution ; Animals ; *Cannibalism ; Female ; Larva ; Male ; Mites/*physiology ; Predatory Behavior ; Sex Factors ; }, abstract = {Cannibalism is a widespread phenomenon in nature, often occurring when food is scarce, for example among predators that have overexploited a local prey population. Instead of cannibalising, predators can disperse, thereby avoiding being cannibalised or cannibalising related conspecifics, which results in inclusive fitness loss. Theory on prey exploitation in ephemeral predator-prey systems predicts that predators may be selected to display prudent predation by dispersing early, thus saving food for their remaining offspring. This is especially advantageous when average relatedness in the local population is high. Less prudent predators refrain from dispersing until all prey are exterminated. These prey exploitation strategies may also have repercussions for cannibalism, especially when it is driven by food shortage. We therefore investigated to what extent adult females and males cannibalise or disperse after prey have been exterminated locally. We used two lines of the haplodiploid predatory mite Phytoseiulus persimilis that were selected for early and late dispersal, respectively. In wind tunnels, we observed the cannibalistic and dispersal behaviour of individual adult predators of these lines on a rose leaf with only conspecific larvae as food. Both selection lines behaved similarly, indicating that selection on dispersal behaviour did not result in correlated effects on cannibalism behaviour. Male predators stayed significantly longer on the leaf and engaged more often in cannibalism than females. The results suggest that there might be gender-specific differences in cannibalistic tendency in relation to dispersal. Future theoretical studies on the evolution of cannibalism and dispersal should take differences between the genders into account.}, }
@article {pmid32966826, year = {2021}, author = {Sun, S and Broom, M and Johanis, M and Rychtář, J}, title = {A mathematical model of kin selection in floral displays.}, journal = {Journal of theoretical biology}, volume = {509}, number = {}, pages = {110470}, doi = {10.1016/j.jtbi.2020.110470}, pmid = {32966826}, issn = {1095-8541}, mesh = {*Flowers ; Models, Theoretical ; Plants ; *Pollination ; Seeds ; }, abstract = {Plants can adjust their competitive traits for acquiring resources in response to the relatedness of their neighbours. Recently, it has been found that plants can alter their investment in traits of attracting pollinators based on kin-interaction. We build a mathematical model to study the optimal floral display to attract pollinators in a patch with kin structure. We show that when plants can attract pollinators to a whole patch through the magnet effect, the floral display should increase with the increasing relatedness of the plants in the patch. Our model also indicates that increasing investment into attracting pollinators is a form of altruism, reducing a plant's own seed production but increasing the contribution of other plants to its fitness. We also predict that seed production should increase with increasing relatedness in the patch. Our model provides the explicit conditions when resource allocation to attract pollinators in response to neighbour relatedness can be favoured by kin selection, and a possible mechanism for the plants to deal with the consequent loss of pollinator diversity and abundance.}, }
@article {pmid32944998, year = {2020}, author = {Erb, WM and Porter, LM}, title = {Variable infant care contributions in cooperatively breeding groups of wild saddleback tamarins.}, journal = {American journal of primatology}, volume = {82}, number = {12}, pages = {e23190}, doi = {10.1002/ajp.23190}, pmid = {32944998}, issn = {1098-2345}, mesh = {Animals ; Bolivia ; Female ; Male ; *Maternal Behavior ; *Paternal Behavior ; Saguinus/*psychology ; Social Behavior ; }, abstract = {Among non-human primates, alloparental infant care is most extensive in callitrichines, and is thought to be particularly costly for tamarins whose helpers may suffer increased energy expenditure, weight loss, and reduced feeding time and mobility. The costs and benefits of infant care likely vary among group members yet very few wild studies have investigated variable infant care contributions. We studied infant care over an 8-month period in four wild groups of saddleback tamarins in Bolivia to evaluate: (a) what forms of infant care are provided, by whom, and when, (b) how individuals adjust their behavior (activity, vigilance, height) while caring for infants, and (c) whether individuals differ in their infant care contributions. We found that infant carrying, food sharing, and grooming varied among groups, and immigrant males-those who joined the group after infants were conceived-participated less in infant care compared to resident males. Adult tamarins fed less, rested more, and increased vigilance while carrying infants. Although we did not detect changes in overall activity budgets between prepartum and postpartum periods, tamarins spent more time scanning their environments postpartum, potentially reflecting increased predation risk to both carriers and infants during this period. Our study provides the first quantitative data on the timing and amount of infant carrying, grooming, and food transfer contributed by all individuals within and among multiple wild groups, filling a critical knowledge gap about the factors affecting infant care, and highlighting evolutionary hypotheses for cooperative breeding in tamarins.}, }
@article {pmid32900316, year = {2020}, author = {Darden, SK and James, R and Cave, JM and Brask, JB and Croft, DP}, title = {Trinidadian guppies use a social heuristic that can support cooperation among non-kin.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1934}, pages = {20200487}, pmid = {32900316}, issn = {1471-2954}, mesh = {Animals ; Biological Evolution ; Cooperative Behavior ; Heuristics ; Poecilia/*physiology ; }, abstract = {Cooperation among non-kin is well documented in humans and widespread in non-human animals, but explaining the occurrence of cooperation in the absence of inclusive fitness benefits has proven a significant challenge. Current theoretical explanations converge on a single point: cooperators can prevail when they cluster in social space. However, we know very little about the real-world mechanisms that drive such clustering, particularly in systems where cognitive limitations make it unlikely that mechanisms such as score keeping and reputation are at play. Here, we show that Trinidadian guppies (Poecilia reticulata) use a 'walk away' strategy, a simple social heuristic by which assortment by cooperativeness can come about among mobile agents. Guppies cooperate during predator inspection and we found that when experiencing defection in this context, individuals prefer to move to a new social environment, despite having no prior information about this new social group. Our results provide evidence in non-human animals that individuals use a simple social partner updating strategy in response to defection, supporting theoretical work applying heuristics to understanding the proximate mechanisms underpinning the evolution of cooperation among non-kin.}, }
@article {pmid32882324, year = {2020}, author = {Guoth, AW and Chernyshova, AM and Thompson, GJ}, title = {Gene-regulatory context of honey bee worker sterility.}, journal = {Bio Systems}, volume = {198}, number = {}, pages = {104235}, doi = {10.1016/j.biosystems.2020.104235}, pmid = {32882324}, issn = {1872-8324}, mesh = {Animals ; Bees/*genetics/physiology ; Cluster Analysis ; Female ; Gene Expression Profiling/*methods ; *Gene Expression Regulation ; Gene Ontology ; *Gene Regulatory Networks ; Insect Proteins/classification/genetics/metabolism ; Male ; Models, Genetic ; Pheromones/metabolism/physiology ; Reproduction/genetics ; Social Behavior ; }, abstract = {The highly organized societies of the Western honey bee Apis mellifera feature a highly reproductive queen at the center of attention and a large cohort of daughters that suppress their own reproduction to help rear more sisters, some of whom become queens themselves. This reproductive altruism is peculiar because in theory it evolves via indirect selection on genes for altruism that are expressed in the sterile workers but not in the reproductive queens. In this study we attempt to situate lists of genes previously implicated in queenright worker sterility into a broader regulatory framework. To do so we use a model bee brain transcriptional regulatory network as a template to infer how sets of genes responsive to ovary-suppressing queen pheromone are functionally interconnected over the model's topology. We predict that genes jointly involved in the regulation of worker sterility should be tightly networked, relative to genes whose functions are unrelated to each other. We find that sets of mapped genes - ranging in size from 17 to 250 - are well dispersed across the network's substructural scaffolds, suggesting that ovary de-activation involves genes that reside within more than one transcriptional regulatory module. For some sets, however, this dispersion is biased into certain areas of the network's substructure. Our analysis identifies the regions enriched for sterility genes and likewise identifies local hub genes that are presumably critical to subnetwork function. Our work offers a glimpse into the gene regulatory context of honey bee worker sterility and uses this context to identify new candidate gene targets for functional analysis. Finally, to the extent that any sterility-related modules identified here have evolved via selection for worker altruism, we can assume that this selection was indirect and of the type specifically invoked by inclusive fitness theory.}, }
@article {pmid32869398, year = {2020}, author = {Giehr, J and Wallner, J and Senninger, L and Ruhland, K and Krüger, T and Heinze, J}, title = {Substantial direct fitness gains of workers in a highly eusocial ant.}, journal = {Molecular ecology}, volume = {29}, number = {19}, pages = {3720-3730}, doi = {10.1111/mec.15586}, pmid = {32869398}, issn = {1365-294X}, mesh = {Animals ; *Ants/genetics ; Behavior, Animal ; Genotype ; Male ; Reproduction/genetics ; Social Behavior ; }, abstract = {Hamilton's theory of inclusive fitness suggests that helpers in animal societies gain fitness indirectly by increasing the reproductive performance of a related beneficiary. Helpers in cooperatively breeding birds, mammals and primitively eusocial wasps may additionally obtain direct fitness through inheriting the nest or mating partner of the former reproductive. Here, we show that also workers of a highly eusocial ant may achieve considerable direct fitness by producing males in both queenless and queenright colonies. We investigated the reproductive success of workers of the ant Temnothorax crassispinus in nature and the laboratory by dissecting workers and determining the origin of males by microsatellite analysis. We show that workers are capable of activating their ovaries and successfully producing their sons independently of the presence of a queen. Genotypes revealed that at least one fifth of the males in natural queenright colonies were not offspring of the queen. Most worker-produced males could be assigned to workers that were unrelated to the queen, suggesting egg-laying by drifting workers.}, }
@article {pmid32814071, year = {2020}, author = {Ohtsuki, H and Rueffler, C and Wakano, JY and Parvinen, K and Lehmann, L}, title = {The components of directional and disruptive selection in heterogeneous group-structured populations.}, journal = {Journal of theoretical biology}, volume = {507}, number = {}, pages = {110449}, doi = {10.1016/j.jtbi.2020.110449}, pmid = {32814071}, issn = {1095-8541}, mesh = {Alleles ; Biological Evolution ; Models, Genetic ; Phenotype ; *Reproduction ; *Selection, Genetic ; }, abstract = {We derive how directional and disruptive selection operate on scalar traits in a heterogeneous group-structured population for a general class of models. In particular, we assume that each group in the population can be in one of a finite number of states, where states can affect group size and/or other environmental variables, at a given time. Using up to second-order perturbation expansions of the invasion fitness of a mutant allele, we derive expressions for the directional and disruptive selection coefficients, which are sufficient to classify the singular strategies of adaptive dynamics. These expressions include first- and second-order perturbations of individual fitness (expected number of settled offspring produced by an individual, possibly including self through survival); the first-order perturbation of the stationary distribution of mutants (derived here explicitly for the first time); the first-order perturbation of pairwise relatedness; and reproductive values, pairwise and three-way relatedness, and stationary distribution of mutants, each evaluated under neutrality. We introduce the concept of individual k-fitness (defined as the expected number of settled offspring of an individual for which k-1 randomly chosen neighbors are lineage members) and show its usefulness for calculating relatedness and its perturbation. We then demonstrate that the directional and disruptive selection coefficients can be expressed in terms individual k-fitnesses with k=1,2,3 only. This representation has two important benefits. First, it allows for a significant reduction in the dimensions of the system of equations describing the mutant dynamics that needs to be solved to evaluate explicitly the two selection coefficients. Second, it leads to a biologically meaningful interpretation of their components. As an application of our methodology, we analyze directional and disruptive selection in a lottery model with either hard or soft selection and show that many previous results about selection in group-structured populations can be reproduced as special cases of our model.}, }
@article {pmid32781951, year = {2020}, author = {Hitchcock, TJ and Gardner, A}, title = {A gene's-eye view of sexual antagonism.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1932}, pages = {20201633}, pmid = {32781951}, issn = {1471-2954}, mesh = {Alleles ; Animals ; Biological Evolution ; Dosage Compensation, Genetic ; Female ; Male ; Reproduction ; *Selection, Genetic ; Sex ; *Sex Characteristics ; X Chromosome ; }, abstract = {Females and males may face different selection pressures. Accordingly, alleles that confer a benefit for one sex often incur a cost for the other. Classic evolutionary theory holds that the X chromosome, whose sex-biased transmission sees it spending more time in females, should value females more than males, whereas autosomes, whose transmission is unbiased, should value both sexes equally. However, recent mathematical and empirical studies indicate that male-beneficial alleles may be more favoured by the X chromosome than by autosomes. Here we develop a gene's-eye-view approach that reconciles the classic view with these recent discordant results, by separating a gene's valuation of female versus male fitness from its ability to induce fitness effects in either sex. We use this framework to generate new comparative predictions for sexually antagonistic evolution in relation to dosage compensation, sex-specific mortality and assortative mating, revealing how molecular mechanisms, ecology and demography drive variation in masculinization versus feminization across the genome.}, }
@article {pmid32779763, year = {2020}, author = {Port, M and Hildenbrandt, H and Pen, I and Schülke, O and Ostner, J and Weissing, FJ}, title = {The evolution of social philopatry in female primates.}, journal = {American journal of physical anthropology}, volume = {173}, number = {3}, pages = {397-410}, doi = {10.1002/ajpa.24123}, pmid = {32779763}, issn = {1096-8644}, mesh = {Animals ; Anthropology, Physical ; Female ; Homing Behavior/*physiology ; *Models, Biological ; Primates/*physiology ; *Social Behavior ; *Social Evolution ; }, abstract = {The transition from solitary life to sociality is considered one of the major transitions in evolution. In primates, this transition is currently not well understood. Traditional verbal models appear insufficient to unravel the complex interplay of environmental and demographic factors involved in the evolution of primate sociality, and recent phylogenetic reconstructions have produced conflicting results. We therefore analyze a theoretical model for the evolution of female social philopatry that sheds new light on the question why most primates live in groups. In individual-based simulations, we study the evolution of dispersal strategies of both resident females and their offspring. The model reveals that social philopatry can evolve through kin selection, even if retention of offspring is costly in terms of within-group resource competition and provides no direct benefits. Our model supports the role of predator avoidance as a selective pressure for group-living in primates, but it also suggests that a second benefit of group-living, communal resource defense, might be required to trigger the evolution of sizable groups. Lastly, our model reveals that seemingly small differences in demographic parameters can have profound effects on primate social evolution.}, }
@article {pmid32688434, year = {2020}, author = {De Moor, D and Roos, C and Ostner, J and Schülke, O}, title = {Bonds of bros and brothers: Kinship and social bonding in postdispersal male macaques.}, journal = {Molecular ecology}, volume = {29}, number = {17}, pages = {3346-3360}, doi = {10.1111/mec.15560}, pmid = {32688434}, issn = {1365-294X}, mesh = {Animals ; Female ; Male ; *Macaca ; Microsatellite Repeats ; *Social Behavior ; }, abstract = {Group-living animals often maintain a few very close affiliative relationships-social bonds-that can buffer them against many of the inevitable costs of gregariousness. Kinship plays a central role in the development of such social bonds. The bulk of research on kin biases in sociality has focused on philopatric females, who typically live in deeply kin-structured systems, with matrilineal dominance rank inheritance and life-long familiarity between kin. Closely related males, in contrast, are usually not close in rank or familiar, which offers the opportunity to test the importance of kinship per se in the formation of social bonds. So far, however, kin biases in male social bonding have only been tested in philopatric males, where familiarity remains a confounding factor. Here, we studied bonds between male Assamese macaques, a species in which males disperse from their natal groups and in which male bonds are known to affect fitness. Combining extensive behavioural data on 43 adult males over a 10-year period with DNA microsatellite relatedness analyses, we find that postdispersal males form stronger relationships with the few close kin available in the group than with the average nonkin. However, males form the majority of their bonds with nonkin and may choose nonkin over available close kin to bond with. Our results show that kinship facilitates bond formation, but is not a prerequisite for it, which suggests that strong bonds are not restricted to kin in male mammals and that animals cooperate for both direct and indirect fitness benefits.}, }
@article {pmid32674869, year = {2020}, author = {Yamamichi, M and Kyogoku, D and Iritani, R and Kobayashi, K and Takahashi, Y and Tsurui-Sato, K and Yamawo, A and Dobata, S and Tsuji, K and Kondoh, M}, title = {Intraspecific Adaptation Load: A Mechanism for Species Coexistence.}, journal = {Trends in ecology &amp; evolution}, volume = {35}, number = {10}, pages = {897-907}, doi = {10.1016/j.tree.2020.05.011}, pmid = {32674869}, issn = {1872-8383}, mesh = {Acclimatization ; *Adaptation, Physiological/genetics ; *Biological Evolution ; Humans ; Population Dynamics ; Reproduction ; }, abstract = {Evolutionary ecological theory suggests that selection arising from interactions with conspecifics, such as sexual and kin selection, may result in evolution of intraspecific conflicts and evolutionary 'tragedy of the commons'. Here, we propose that such an evolution of conspecific conflicts may affect population dynamics in a way that enhances species coexistence. Empirical evidence and theoretical models suggest that more abundant species is more susceptible to invasion of 'selfish' individuals that increase their own reproductive success at the expense of population growth (intraspecific adaptation load). The density-dependent intraspecific adaptation load gives rise to a self-regulation mechanism at the population level, and stabilizes species coexistence at the community level by negative frequency-dependence.}, }
@article {pmid32673089, year = {2020}, author = {Ducouret, P and Romano, A and Dreiss, AN and Marmaroli, P and Falourd, X and Bincteux, M and Roulin, A}, title = {Elder Barn Owl Nestlings Flexibly Redistribute Parental Food according to Siblings' Need or in Return for Allopreening.}, journal = {The American naturalist}, volume = {196}, number = {2}, pages = {257-269}, doi = {10.1086/709106}, pmid = {32673089}, issn = {1537-5323}, mesh = {Animals ; Behavior, Animal ; Competitive Behavior ; Cooperative Behavior ; *Feeding Behavior ; Female ; Grooming ; Male ; Nesting Behavior ; *Siblings ; Strigiformes/*physiology ; Switzerland ; Vocalization, Animal ; }, abstract = {Kin selection and reciprocation of biological services are distinct theories invoked to explain the origin and evolutionary maintenance of altruistic and cooperative behaviors. Although these behaviors are not considered to be mutually exclusive, the cost-benefit balance of behaving altruistically or cooperating reciprocally and the conditions promoting a switch between such different strategies have rarely been tested. Here, we examine the association between allofeeding, allopreening, and vocal solicitations in wild barn owl (Tyto alba) broods under different food abundance conditions: natural food provisioning and after an experimental food supplementation. Allofeeding was performed mainly by elder nestlings (hatching is asynchronous) in prime condition, especially when the cost of forgoing a prey was small (when parents allocated more prey to the food donor and after food supplementation). Nestlings preferentially shared food with the siblings that emitted very intense calls, thus potentially increasing indirect fitness benefits, or with the siblings that provided extensive allopreening to the donor, thus possibly promoting direct benefits from reciprocation. Finally, allopreening was mainly directed toward older siblings, perhaps to maximize the probability of being fed in return. Helping behavior among relatives can therefore be driven by both kin selection and direct cooperation, although it is dependent on the contingent environmental conditions.}, }
@article {pmid32665274, year = {2020}, author = {Kogay, R and Wolf, YI and Koonin, EV and Zhaxybayeva, O}, title = {Selection for Reducing Energy Cost of Protein Production Drives the GC Content and Amino Acid Composition Bias in Gene Transfer Agents.}, journal = {mBio}, volume = {11}, number = {4}, pages = {}, pmid = {32665274}, issn = {2150-7511}, mesh = {Alphaproteobacteria/*genetics ; Amino Acids ; Bacterial Proteins/*genetics ; Bacteriophages/genetics ; Base Composition ; *Gene Transfer, Horizontal ; Genes, Viral ; Genome, Bacterial ; Prophages/genetics ; }, abstract = {Gene transfer agents (GTAs) are virus-like elements integrated into bacterial genomes, particularly, those of Alphaproteobacteria The GTAs can be induced under conditions of nutritional stress, incorporate random fragments of bacterial DNA into miniphage particles, lyse the host cells, and infect neighboring bacteria, thus enhancing horizontal gene transfer. We show that GTA genes evolve under conditions of pronounced positive selection for the reduction of the energy cost of protein production as shown by comparison of the amino acid compositions with those of both homologous viral genes and host genes. The energy saving in GTA genes is comparable to or even more pronounced than that in the genes encoding the most abundant, essential bacterial proteins. In cases in which viruses acquire genes from GTAs, the bias in amino acid composition disappears in the course of evolution, showing that reduction of the energy cost of protein production is an important factor of evolution of GTAs but not bacterial viruses. These findings strongly suggest that GTAs represent bacterial adaptations rather than selfish, virus-like elements. Because GTA production kills the host cell and does not propagate the GTA genome, it appears likely that the GTAs are retained in the course of evolution via kin or group selection. Therefore, we hypothesize that GTAs facilitate the survival of bacterial populations under energy-limiting conditions through the spread of metabolic and transport capabilities via horizontal gene transfer and increases in nutrient availability resulting from the altruistic suicide of GTA-producing cells.IMPORTANCE Kin selection and group selection remain controversial topics in evolutionary biology. We argue that these types of selection are likely to operate in bacterial populations by showing that bacterial gene transfer agents (GTAs), but not related viruses, evolve under conditions of positive selection for the reduction of the energy cost of GTA particle production. We hypothesize that GTAs are dedicated devices mediating the survival of bacteria under conditions of nutrient limitation. The benefits conferred by GTAs under nutritional stress conditions appear to include horizontal dissemination of genes that could provide bacteria with enhanced capabilities for nutrient utilization and increases of nutrient availability occurring through the lysis of GTA-producing bacteria.}, }
@article {pmid32651398, year = {2020}, author = {O'Corry-Crowe, G and Suydam, R and Quakenbush, L and Smith, TG and Lydersen, C and Kovacs, KM and Orr, J and Harwood, L and Litovka, D and Ferrer, T}, title = {Group structure and kinship in beluga whale societies.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {11462}, pmid = {32651398}, issn = {2045-2322}, abstract = {Evolutionary explanations for mammalian sociality typically center on inclusive-fitness benefits of associating and cooperating with close kin, or close maternal kin as in some whale societies, including killer and sperm whales. Their matrilineal structure has strongly influenced the thinking about social structure in less well-studied cetaceans, including beluga whales. In a cross-sectional study of group structure and kinship we found that belugas formed a limited number of distinct group types, consistently observed across populations and habitats. Certain behaviours were associated with group type, but group membership was often dynamic. MtDNA-microsatellite profiling combined with relatedness and network analysis revealed, contrary to predictions, that most social groupings were not predominantly organized around close maternal relatives. They comprised both kin and non-kin, many group members were paternal rather than maternal relatives, and unrelated adult males often traveled together. The evolutionary mechanisms that shape beluga societies are likely complex; fitness benefits may be achieved through reciprocity, mutualism and kin selection. At the largest scales these societies are communities comprising all ages and both sexes where multiple social learning pathways involving kin and non-kin can foster the emergence of cultures. We explore the implications of these findings for species management and the evolution of menopause.}, }
@article {pmid32637404, year = {2020}, author = {Hockings, N and Howard, D}, title = {New Biological Morphogenetic Methods for Evolutionary Design of Robot Bodies.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {8}, number = {}, pages = {621}, pmid = {32637404}, issn = {2296-4185}, abstract = {We present some currently unused morphogenetic mechanisms from evolutionary biology and guidelines for transfer to evolutionary robotics. (1) DNA patterns providing mutation of mutability, lead to canalization of evolvable bauplans, via kin selection. (2) Morphogenetic mechanisms (i) Epigenetic cell lines provide functional cell types, and identification of cell descent. (ii) Local anatomical coordinates based on diffusion of morphogens, facilitate evolvable genetic parameterizations of complex phenotypes (iii) Remodeling in response to mechanical forces facilitates robust production of well-integrated phenotypes of greater complexity than the genome. An approach is proposed for the tractable application of mutation-of-mutability and morphogenetic mechanisms in evolutionary robotics. The purpose of these methods, is to facilitate production of robot mechanisms of the subtlety, efficiency, and efficacy of the musculoskeletal and dermal systems of animals.}, }
@article {pmid32627189, year = {2020}, author = {Araya-Ajoy, YG and Westneat, DF and Wright, J}, title = {Pathways to social evolution and their evolutionary feedbacks.}, journal = {Evolution; international journal of organic evolution}, volume = {74}, number = {9}, pages = {1894-1907}, doi = {10.1111/evo.14054}, pmid = {32627189}, issn = {1558-5646}, mesh = {Animals ; *Biological Evolution ; *Phenotype ; *Social Evolution ; }, abstract = {In the context of social evolution, the ecological drivers of selection are the phenotypes of other individuals. The social environment can thus evolve, potentially changing the adaptive value for different social strategies. Different branches of evolutionary biology have traditionally focused on different aspects of these feedbacks. Here, we synthesize behavioral ecology theory concerning evolutionarily stable strategies when fitness is frequency dependent with quantitative genetic models providing statistical descriptions of evolutionary responses to social selection. Using path analyses, we review how social interactions influence the strength of selection and how social responsiveness, social impact, and non-random social assortment affect responses to social selection. We then detail how the frequency-dependent nature of social interactions fits into this framework and how it imposes selection on traits mediating social responsiveness, social impact, and social assortment, further affecting evolutionary dynamics. Throughout, we discuss the parameters in quantitative genetics models of social evolution from a behavioral ecology perspective and identify their statistical counterparts in empirical studies. This integration of behavioral ecology and quantitative genetic perspectives should lead to greater clarity in the generation of hypotheses and more focused empirical research regarding evolutionary pathways and feedbacks inherent in specific social interactions.}, }
@article {pmid32614977, year = {2020}, author = {Lee, DS and Mandalaywala, TM and Dubuc, C and Widdig, A and Higham, JP}, title = {Higher early life mortality with lower infant body mass in a free-ranging primate.}, journal = {The Journal of animal ecology}, volume = {89}, number = {10}, pages = {2300-2310}, doi = {10.1111/1365-2656.13291}, pmid = {32614977}, issn = {1365-2656}, support = {P40 OD012217/OD/NIH HHS/United States ; }, mesh = {Animals ; Female ; Humans ; Macaca mulatta ; *Mothers ; Phenotype ; Puerto Rico ; *Reproduction ; }, abstract = {Traits that reflect the amount of energy allocated to offspring by mothers, such as infant body mass, are predicted to have long-lasting effects on offspring fitness. In very long-lived species, such as anthropoid primates, where long-lasting and obligate parental care is required for successful recruitment of offspring, there are few studies on the fitness implications of low body mass among infants. Using body mass data collected from 253 free-ranging rhesus macaque Macaca mulatta infants on Cayo Santiago, Puerto Rico, we examined if lower infant body mass predicts lower chance of survival through to reproductive maturation (4th year of life). We also used data on inter-birth intervals and suckling behaviours to determine whether the duration of maternal care was adjusted to infant body mass. Rhesus macaque infants experienced on average 5% reduced hazard of death for an increase in body mass of 0.1 SD (~100 g) above the mean within their age-sex class. The positive association between body mass and early life survival was most pronounced in the 1st year of life. Infant body mass tended to be lower if mothers were young or old, but the link between infant body mass and early life survival remained after controlling for maternal age. This finding suggests that maternal effects on early life survival such as maternal age may act through their influence on infant body mass. Mothers of heavier infants were less likely to be delayed in subsequent reproduction, but the estimated association slightly overlapped with zero. The timing of the last week of suckling did not differ by infant body mass. Using infant body mass data that has been rarely available from free-ranging primates, our study provides comparative evidence to strengthen the existing body of literature on the fitness implications of variation in infant body mass.}, }
@article {pmid32605521, year = {2020}, author = {Keaney, TA and Wong, HWS and Dowling, DK and Jones, TM and Holman, L}, title = {Sibling rivalry versus mother's curse: can kin competition facilitate a response to selection on male mitochondria?.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1930}, pages = {20200575}, pmid = {32605521}, issn = {1471-2954}, mesh = {Animals ; Drosophila melanogaster ; Female ; Haplotypes ; Male ; Maternal Inheritance ; *Mitochondria ; *Selection, Genetic ; Siblings ; }, abstract = {Assuming that fathers never transmit mitochondrial DNA (mtDNA) to their offspring, mitochondrial mutations that affect male fitness are invisible to direct selection on males, leading to an accumulation of male-harming alleles in the mitochondrial genome (mother's curse). However, male phenotypes encoded by mtDNA can still undergo adaptation via kin selection provided that males interact with females carrying related mtDNA, such as their sisters. Here, using experiments with Drosophila melanogaster carrying standardized nuclear DNA but distinct mitochondrial DNA, we test whether the mitochondrial haplotype carried by interacting pairs of larvae affects survival to adulthood, as well as the fitness of the adults. Although mtDNA had no detectable direct or indirect genetic effect on larva-to-adult survival, the fitness of male and female adults was significantly affected by their own mtDNA and the mtDNA carried by their social partner in the larval stage. Thus, mtDNA mutations that alter the effect of male larvae on nearby female larvae (which often carry the same mutation, due to kinship) could theoretically respond to kin selection. We discuss the implications of our findings for the evolution of mitochondria and other maternally inherited endosymbionts.}, }
@article {pmid32581916, year = {2020}, author = {Gyuris, P and Kozma, L and Kisander, Z and Láng, A and Ferencz, T and Kocsor, F}, title = {Sibling Relations in Patchwork Families: Co-residence Is More Influential Than Genetic Relatedness.}, journal = {Frontiers in psychology}, volume = {11}, number = {}, pages = {993}, pmid = {32581916}, issn = {1664-1078}, abstract = {In "patchwork" families, full siblings, maternal and paternal half-siblings, and non-related children are raised together, and sometimes, genetically related children are separated. As their number is steadily growing, the investigation of the factors that influence within-family relations is becoming more important. Our aim was to explore whether people differentiate between half- and full-siblings in their social relations as implied by the theory of inclusive fitness, and to test whether co-residence or genetic relatedness improves sibling relations to a larger extent. We administered the Sibling Relationship Questionnaire to 196 individuals who were in contact with full-, half-, or step-siblings in their childhood. We built Generalized Linear Mixed Models models to test for the effects of relatedness and co-residence on sibling relations. In general, a higher degree of relatedness was associated with better sibling relations, but only among those who did not live together during childhood. Co-resident siblings' overall pattern of relation quality was not influenced by the actual level of genetic relatedness. In contrast to this, full siblings reported having experienced more conflicts during childhood than half-siblings, possibly resulting from enhanced competition for the same parental resources. The results suggest that inclusive fitness drives siblings' relations even in recent industrial societies. However, among individuals who live together, the effect of relatedness might be obscured by fitness interdependence and the subjective feeling of kinship.}, }
@article {pmid32537201, year = {2020}, author = {Pang, TY}, title = {On age-specific selection and extensive lifespan beyond menopause.}, journal = {Royal Society open science}, volume = {7}, number = {5}, pages = {191972}, pmid = {32537201}, issn = {2054-5703}, abstract = {Standard evolutionary theory of ageing predicts weaker purifying selection on genes critical to later life stages. Prolonged post-reproductive lifespan (PPRLS), observed only in a few species like humans, is likely a result of disparate relaxation of purifying selection on survival and reproduction in late life stages. While the exact origin of PPRLS is under debate, many researchers agree on hypotheses like mother-care and grandmother-care, which ascribe PPRLS to investment into future generations-provision to one's descendants to enhance their overall reproductive success. Here, we simulate an agent-based model, which properly accounts for age-specific selection, to examine how different investment strategies affect the strength of purifying selection on survival and reproduction. We observed in the simulations that investment strategies that allow a female individual to remain contributive to its own descendants (infants and adults) at late life stages may lead to differential relaxation of selection on survival and reproduction, and incur the adaptive evolution of PPRLS.}, }
@article {pmid32502408, year = {2020}, author = {Granato, ET and Foster, KR}, title = {The Evolution of Mass Cell Suicide in Bacterial Warfare.}, journal = {Current biology : CB}, volume = {30}, number = {14}, pages = {2836-2843.e3}, pmid = {32502408}, issn = {1879-0445}, support = {/WT_/Wellcome Trust/United Kingdom ; 209397/Z/17/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Bacterial Toxins/*metabolism/*toxicity ; *Biological Evolution ; Cell Death/*drug effects ; Colicins/*metabolism/*toxicity ; Escherichia coli/drug effects/*metabolism/pathogenicity/*physiology ; }, abstract = {Behaviors that cause the death of an actor are typically strongly disfavored by natural selection, and yet many bacteria undergo cell lysis to release anti-competitor toxins [1-5]. This behavior is most easily explained if only a small proportion of cells die to release toxins and help their clonemates, but the frequency of cells that actually lyse during bacterial warfare is unknown. The challenge is finding a way to distinguish cells that have undergone programmed suicide from those that were simply killed by a competitor's toxin. We developed a two-color fluorescence reporter assay in Escherichia coli to overcome this problem. This revealed conditions where nearly all cells undergo programmed lysis. Specifically, adding a DNA-damaging toxin (DNase colicin) from another strain induced mass cell suicide where ∼85% of cells lysed to release their own toxins. Time-lapse 3D confocal microscopy showed that self-lysis occurs locally at even higher frequencies (∼94%) at the interface between toxin-producing colonies. By exposing E. coli that do not perform lysis to the DNase colicin, we found that mass lysis occurs when cells are going to die anyway from toxin exposure. From an evolutionary perspective, this renders the behavior cost-free as these cells have zero reproductive potential. This helps to explain how mass cell suicide can evolve, as any small benefit to surviving clonemates can lead to this retaliatory strategy being favored by natural selection. Our findings have parallels to the suicidal attacks of social insects [6-9], which are also performed by individuals with low reproductive potential.}, }
@article {pmid32469661, year = {2020}, author = {Downing, PA and Griffin, AS and Cornwallis, CK}, title = {The Benefits of Help in Cooperative Birds: Nonexistent or Difficult to Detect?.}, journal = {The American naturalist}, volume = {195}, number = {6}, pages = {1085-1091}, doi = {10.1086/708515}, pmid = {32469661}, issn = {1537-5323}, mesh = {Animals ; Behavior, Animal ; *Cooperative Behavior ; Nesting Behavior/physiology ; Passeriformes/*physiology ; Reproduction/*physiology ; }, abstract = {In birds that breed cooperatively in family groups, adult offspring often delay dispersal to assist the breeding pair in raising their young. Kin selection is thought to play an important role in the evolution of this breeding system. However, evidence supporting the underlying assumption that helpers increase the reproductive success of breeders is inconsistent. In 10 out of 19 species where the effect of helpers on breeder reproductive success has been estimated while controlling for the effects of breeder and territory quality, no benefits of help were detected. Here, we use phylogenetic meta-analysis to show that the inconsistent evidence for helper benefits across species is explained by study design. After accounting for low sample sizes and the different study designs used to control for breeder and territory quality, we found that helpers consistently enhanced the reproductive success of breeders. Therefore, the assumption that helpers increase breeder reproductive success is supported by evidence across cooperatively breeding birds.}, }
@article {pmid32451427, year = {2020}, author = {Faria, GS and Gardner, A and Carazo, P}, title = {Kin discrimination and demography modulate patterns of sexual conflict.}, journal = {Nature ecology &amp; evolution}, volume = {4}, number = {8}, pages = {1141-1148}, pmid = {32451427}, issn = {2397-334X}, support = {771387/ERC_/European Research Council/International ; }, mesh = {Animals ; Demography ; Male ; *Models, Theoretical ; *Sexual Behavior, Animal ; }, abstract = {Recent years have seen an explosion of interest in the overlap between kin selection and sexual selection, particularly concerning how kin selection can put the brakes on harmful sexual conflict. However, there remains a significant disconnect between theory and empirical research. Whilst empirical work has focused on kin-discriminating behaviour, theoretical models have assumed indiscriminating behaviour. Additionally, theoretical work makes particular demographic assumptions that constrain the relationship between genetic relatedness and the scale of competition, and it is not clear that these assumptions reflect the natural setting in which sexual conflict has been empirically studied. Here, we plug this gap between current theoretical and empirical understanding by developing a mathematical model of sexual conflict that incorporates kin discrimination and different patterns of dispersal. We find that kin discrimination and group dispersal inhibit harmful male behaviours at an individual level, but kin discrimination intensifies sexual conflict at the population level.}, }
@article {pmid32445518, year = {2021}, author = {Timming, AR and French, MT}, title = {The effect of genetic vs nongenetic parental care on adult children's income and wealth in later life: An evolutionary analysis.}, journal = {American journal of human biology : the official journal of the Human Biology Council}, volume = {33}, number = {1}, pages = {e23431}, doi = {10.1002/ajhb.23431}, pmid = {32445518}, issn = {1520-6300}, mesh = {Adult ; Adult Children/*statistics &amp; numerical data ; *Biological Evolution ; Female ; Humans ; Income/*statistics &amp; numerical data ; Longitudinal Studies ; Male ; *Maternal Behavior ; *Parents ; *Paternal Behavior ; United States ; Young Adult ; }, abstract = {OBJECTIVE: Using Wave IV of the National Longitudinal Study of Adolescent to Adult Health data set, this preregistered study set out to investigate the effect of parental care arrangements (eg, genetically related parents, adoptive, step/ foster, genetic nonparental relative, and no parental figure) on adult children's income and wealth in later life.<br><br>METHODS: Consistent with the preregistration plan, multivariate analyses of covariance were first used to examine, separately, the effects of paternal and maternal care arrangements on children's income and wealth in later life. Further post hoc exploratory analyses were carried out to evaluate the robustness of the findings.<br><br>RESULTS: The results indicate that individual earnings in later life are unrelated to paternal care arrangements, thus questioning a key tenet of kin selection theory. However, children raised by biological fathers and adoptive fathers still enjoy significant economic advantages over nongenetic father figures and homes without fathers in relation to household income and wealth.<br><br>CONCLUSIONS: Prevailing theories suggest that children raised by relatives, nongenetically related parents, and no father or mother suffer from a lack of parental investment that should manifest itself in reduced earnings and assets in adulthood. These theories are only partially correct, with evidence pointing to no deleterious effect of variable parental arrangements on individual earnings.}, }
@article {pmid32440290, year = {2020}, author = {Termignoni-Garcia, F and Louder, MIM and Balakrishnan, CN and O'Connell, L and Edwards, SV}, title = {Prospects for sociogenomics in avian cooperative breeding and parental care.}, journal = {Current zoology}, volume = {66}, number = {3}, pages = {293-306}, pmid = {32440290}, issn = {1674-5507}, abstract = {For the last 40 years, the study of cooperative breeding (CB) in birds has proceeded primarily in the context of discovering the ecological, geographical, and behavioral drivers of helping. The advent of molecular tools in the early 1990s assisted in clarifying the relatedness of helpers to those helped, in some cases, confirming predictions of kin selection theory. Methods for genome-wide analysis of sequence variation, gene expression, and epigenetics promise to add new dimensions to our understanding of avian CB, primarily in the area of molecular and developmental correlates of delayed breeding and dispersal, as well as the ontogeny of achieving parental status in nature. Here, we outline key ways in which modern -omics approaches, in particular genome sequencing, transcriptomics, and epigenetic profiling such as ATAC-seq, can be used to add a new level of analysis of avian CB. Building on recent and ongoing studies of avian social behavior and sociogenomics, we review how high-throughput sequencing of a focal species or clade can provide a robust foundation for downstream, context-dependent destructive and non-destructive sampling of specific tissues or physiological states in the field for analysis of gene expression and epigenetics. -Omics approaches have the potential to inform not only studies of the diversification of CB over evolutionary time, but real-time analyses of behavioral interactions in the field or lab. Sociogenomics of birds represents a new branch in the network of methods used to study CB, and can help clarify ways in which the different levels of analysis of CB ultimately interact in novel and unexpected ways.}, }
@article {pmid32402118, year = {2020}, author = {Sapp, JR and Yost, J and Lyon, BE}, title = {The socially parasitic ant Polyergus mexicanus has host-associated genetic population structure and related neighbouring colonies.}, journal = {Molecular ecology}, volume = {29}, number = {11}, pages = {2050-2062}, doi = {10.1111/mec.15468}, pmid = {32402118}, issn = {1365-294X}, mesh = {Animals ; *Ants/genetics ; *Genetics, Population ; Host-Parasite Interactions/genetics ; Microsatellite Repeats ; *Parasites/genetics ; }, abstract = {The genetic structure of populations can be both a cause and a consequence of ecological interactions. For parasites, genetic structure may be a consequence of preferences for host species or of mating behaviour. Conversely, genetic structure can influence where conspecific interactions among parasites lay on a spectrum from cooperation to conflict. We used microsatellite loci to characterize the genetic structure of a population of the socially parasitic dulotic (aka "slave-making") ant (Polyergus mexicanus), which is known for its host-specificity and conspecific aggression. First, we assessed whether the pattern of host species use by the parasite has influenced parasite population structure. We found that host species use was correlated with subpopulation structure, but this correlation was imperfect: some subpopulations used one host species nearly exclusively, while others used several. Second, we examined the viscosity of the parasite population by measuring the relatedness of pairs of neighbouring parasitic ant colonies at varying distances from each other. Although natural history observations of local dispersal by queens suggested the potential for viscosity, there was no strong correlation between relatedness and distance between colonies. However, 35% of colonies had a closely related neighbouring colony, indicating that kinship could potentially affect the nature of some interactions between colonies of this social parasite. Our findings confirm that ecological forces like host species selection can shape the genetic structure of parasite populations, and that such genetic structure has the potential to influence parasite-parasite interactions in social parasites via inclusive fitness.}, }
@article {pmid32398794, year = {2020}, author = {Schausberger, P and Çekin, D}, title = {Plastic female choice to optimally balance (k)in- and out-breeding in a predatory mite.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {7861}, pmid = {32398794}, issn = {2045-2322}, mesh = {Acrylates ; Animals ; Breeding ; Female ; Greece ; Inbreeding ; Male ; Mites/classification/*physiology ; Plastics ; Predatory Behavior/physiology ; Reproduction/physiology ; Sexual Behavior, Animal/*physiology ; Sicily ; *Social Behavior ; }, abstract = {Both close inbreeding and extreme outbreeding may negatively affect direct fitness. Optimal outbreeding theory suggests that females should preferentially mate with distantly related males. (K)in breeding theory suggests that, at similar direct fitness costs of close inbreeding and extreme outbreeding, females should prefer close kin to non-kin. Empirical evidence of plastic female choice for an optimal balance between close inbreeding and extreme outbreeding remains elusive. We tested the combined predictions of optimal outbreeding and (k)in breeding theories in predatory mites Phytoseiulus persimilis from two origins, Sicily and Greece, which suffer from both close inbreeding and extreme outbreeding depression. In three separate experiments, virgin females were presented binary choices between familiar and unfamiliar brothers, and between familiar/unfamiliar brothers and distant kin or non-kin. Females of Greece but not Sicily preferred unfamiliar to familiar brothers. Females of both origins preferred distant kin to unfamiliar and familiar brothers but preferred unfamiliar brothers to non-kin. Females of Sicily but not Greece preferred familiar brothers to non-kin. The suggested kin recognition mechanisms are phenotype matching and direct familiarity, with finer-tuned recognition abilities of Greece females. Overall, our experiments suggest that flexible mate choice by P. persimilis females allows optimally balancing inclusive fitness trade-offs.}, }
@article {pmid32369588, year = {2020}, author = {Bhattacharjee, S and Mishra, AK}, title = {The tale of caspase homologues and their evolutionary outlook: deciphering programmed cell death in cyanobacteria.}, journal = {Journal of experimental botany}, volume = {71}, number = {16}, pages = {4639-4657}, pmid = {32369588}, issn = {1460-2431}, mesh = {*Apoptosis ; Biological Evolution ; Caspases/genetics/metabolism ; *Cyanobacteria/genetics/metabolism ; Proteolysis ; }, abstract = {Programmed cell death (PCD), a genetically orchestrated mechanism of cellular demise, is paradoxically required to support life. As in lower eukaryotes and bacteria, PCD in cyanobacteria is poorly appreciated, despite recent biochemical and molecular evidence that supports its existence. Cyanobacterial PCD is an altruistic reaction to stressful conditions that significantly enhances genetic diversity and inclusive fitness of the population. Recent bioinformatic analysis has revealed an abundance of death-related proteases, i.e. orthocaspases (OCAs) and their mutated variants, in cyanobacteria, with the larger genomes of morphologically complex strains harbouring most of them. Sequence analysis has depicted crucial accessory domains along with the proteolytic p20-like sub-domain in OCAs, predicting their functional versatility. However, the cascades involved in sensing death signals, their transduction, and the downstream expression and activation of OCAs remain to be elucidated. Here, we provide a comprehensive description of the attempts to identify mechanisms of PCD and the existence and importance of OCAs based on in silico approaches. We also review the evolutionary and ecological significance of PCD in cyanobacteria. In the future, the analysis of cyanobacterial PCD will identify novel proteins that have varied functional roles in signalling cascades and also help in understanding the incipient mechanism of PCD morphotype(s) from where eukaryotic PCD might have originated.}, }
@article {pmid32364789, year = {2020}, author = {Thünken, T and Hesse, S and Meuthen, D}, title = {Increased Levels of Perceived Competition Decrease Juvenile Kin-Shoaling Preferences in a Cichlid Fish.}, journal = {The American naturalist}, volume = {195}, number = {5}, pages = {868-875}, doi = {10.1086/707747}, pmid = {32364789}, issn = {1537-5323}, mesh = {Animals ; Cichlids/*physiology ; Competitive Behavior ; Food Deprivation ; Genetic Fitness ; Siblings ; *Social Behavior ; }, abstract = {Inclusive fitness theory predicts that individuals can increase their indirect fitness by grouping with kin. However, kin grouping also increases competition between kin, which potentially outweighs its benefits. The level of kin competition is contingent on environmental conditions and thus highly variable. Hence, individuals should benefit from plastically adjusting kin discrimination according to the expected level of kin competition. Here, we investigate whether perceived high competition affects juvenile kin-shoaling preferences in the cichlid Pelvicachromis taeniatus. Juveniles were given the choice between two shoals consisting of either kin or nonkin. Levels of perceived competition were manipulated through food limitation in the face of the differential energy expenditure of differently sized fish. The preference to shoal with kin decreased with increasing levels of perceived competition; small food-deprived individuals avoided kin. Shoaling with kin under strong competition may reduce individual indirect fitness. Hence, individuals can likely improve their inclusive fitness by plastically adjusting their kin-grouping preferences.}, }
@article {pmid32332728, year = {2020}, author = {Makarenko, R and Denis, C and Francesconi, S and Gangloff, S and Arcangioli, B}, title = {Nitrogen starvation reveals the mitotic potential of mutants in the S/MAPK pathways.}, journal = {Nature communications}, volume = {11}, number = {1}, pages = {1973}, pmid = {32332728}, issn = {2041-1723}, mesh = {Coculture Techniques ; DNA/metabolism ; Flow Cytometry ; Genetic Variation ; Genotype ; *MAP Kinase Signaling System ; *Mitosis ; *Mutation ; Nitrogen/*physiology ; Phenotype ; Protein Serine-Threonine Kinases/genetics ; Saccharomyces cerevisiae/genetics/physiology ; Schizosaccharomyces/*genetics/*physiology ; Schizosaccharomyces pombe Proteins/genetics ; Sequence Analysis, DNA ; Signal Transduction ; Stochastic Processes ; }, abstract = {The genetics of quiescence is an emerging field compared to that of growth, yet both states generate spontaneous mutations and genetic diversity fueling evolution. Reconciling mutation rates in dividing conditions and mutation accumulation as a function of time in non-dividing situations remains a challenge. Nitrogen-starved fission yeast cells reversibly arrest proliferation, are metabolically active and highly resistant to a variety of stresses. Here, we show that mutations in stress- and mitogen-activated protein kinase (S/MAPK) signaling pathways are enriched in aging cultures. Targeted resequencing and competition experiments indicate that these mutants arise in the first month of quiescence and expand clonally during the second month at the expense of the parental population. Reconstitution experiments show that S/MAPK modules mediate the sacrifice of many cells for the benefit of some mutants. These findings suggest that non-dividing conditions promote genetic diversity to generate a social cellular environment prone to kin selection.}, }
@article {pmid37588364, year = {2020}, author = {van Veelen, M}, title = {The group selection-inclusive fitness equivalence claim: not true and not relevant.}, journal = {Evolutionary human sciences}, volume = {2}, number = {}, pages = {e11}, pmid = {37588364}, issn = {2513-843X}, abstract = {The debate on (cultural) group selection regularly suffers from an inclusive fitness overdose. The classical view is that all group selection is kin selection, and that Hamilton's rule works for all models. I claim that not all group selection is kin selection, and that Hamilton's rule does not always get the direction of selection right. More importantly, I will argue that the paper by Smith (2020; Cultural group selection and human cooperation: a conceptual and empirical review. Evolutionary Human Sciences, 2) shows that inclusive fitness is not particularly relevant for much of the empirical evidence relating to the question whether or not cultural group selection shaped human behaviour.}, }
@article {pmid32313691, year = {2020}, author = {Madgwick, PG and Wolf, JB}, title = {Evolution of strategic cooperation.}, journal = {Evolution letters}, volume = {4}, number = {2}, pages = {164-175}, pmid = {32313691}, issn = {2056-3744}, abstract = {Group-beneficial behaviors have presented a long-standing challenge for evolutionary theory because, although their benefits are available to all group members, their costs are borne by individuals. Consequently, an individual could benefit from "cheating" their group mates by not paying the costs while still reaping the benefits. There have been many proposed evolutionary mechanisms that could favor cooperation (and disfavor cheating) in particular circumstances. However, if cooperation is still favored in some circumstances, then we might expect evolution to favor strategic cooperation, where the level of contribution toward group-beneficial behavior is varied in response to the social context. To uncover how and why individuals should contribute toward group-beneficial behavior across social contexts, we model strategic cooperation as an evolutionary game where players can quantitatively adjust the amount they contribute toward group-beneficial behavior. We find that the evolutionarily stable strategy (ESS) predicts, unsurprisingly, that players should contribute in relation to their relatedness to the group. However, we surprisingly find that players often contribute to cooperation in such a way that their fitness is inverse to their relatedness to the group such that those that contribute to cooperation end up with the same return from group-beneficial behavior, essentially removing any potential advantage of higher relatedness. These results bring to light a paradox of group-beneficial cooperation: groups do best when they contain highly related individuals, but those with the highest relatedness to the group will often have the lowest fitness within the group.}, }
@article {pmid32301222, year = {2020}, author = {Galimov, ER and Gems, D}, title = {Shorter life and reduced fecundity can increase colony fitness in virtual Caenorhabditis elegans.}, journal = {Aging cell}, volume = {19}, number = {5}, pages = {e13141}, pmid = {32301222}, issn = {1474-9726}, support = {BB/R01356X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Caenorhabditis elegans/*genetics ; Cellular Senescence/*genetics ; Fertility/*genetics ; Longevity/*genetics ; }, abstract = {In the nematode Caenorhabditis elegans, loss of function of many genes leads to increases in lifespan, sometimes of a very large magnitude. Could this reflect the occurrence of programmed death that, like apoptosis of cells, promotes fitness? The notion that programmed death evolves as a mechanism to remove worn out, old individuals in order to increase food availability for kin is not supported by classic evolutionary theory for most species. However, it may apply in organisms with colonies of closely related individuals such as C. elegans in which largely clonal populations subsist on spatially limited food patches. Here, we ask whether food competition between nonreproductive adults and their clonal progeny could favor programmed death by using an in silico model of C. elegans. Colony fitness was estimated as yield of dauer larva propagules from a limited food patch. Simulations showed that not only shorter lifespan but also shorter reproductive span and reduced adult feeding rate can increase colony fitness, potentially by reducing futile food consumption. Early adult death was particularly beneficial when adult food consumption rate was high. These results imply that programmed, adaptive death could promote colony fitness in C. elegans through a consumer sacrifice mechanism. Thus, C. elegans lifespan may be limited not by aging in the usual sense but rather by apoptosis-like programmed death.}, }
@article {pmid32279381, year = {2020}, author = {Lymbery, SJ and Wyber, B and Tomkins, JL and Simmons, LW}, title = {No evidence for divergence in male harmfulness or female resistance in response to changes in the opportunity for dispersal.}, journal = {Journal of evolutionary biology}, volume = {33}, number = {7}, pages = {966-978}, doi = {10.1111/jeb.13628}, pmid = {32279381}, issn = {1420-9101}, mesh = {*Animal Distribution ; Animals ; *Biological Evolution ; *Coleoptera ; Female ; Male ; Models, Genetic ; Selection, Genetic ; *Sexual Behavior, Animal ; }, abstract = {The outcome of sexual conflict can depend on the social environment, as males respond to changes in the inclusive fitness payoffs of harmfulness and harm females less when they compete with familiar relatives. Theoretical models also predict that if limited male dispersal predictably enhances local relatedness while maintaining global competition, kin selection can produce evolutionary divergences in male harmfulness among populations. Experimental tests of these predictions, however, are rare. We assessed rates of dispersal in female and male seed beetles Callosobruchus maculatus, a model species for studies of sexual conflict, in an experimental setting. Females dispersed significantly more often than males, but dispersing males travelled just as far as dispersing females. Next, we used experimental evolution to test whether limiting dispersal allowed the action of kin selection to affect divergence in male harmfulness and female resistance. Populations of C. maculatus were evolved for 20 and 25 generations under one of three dispersal regimens: completely free dispersal, limited dispersal and no dispersal. There was no divergence among treatments in female reproductive tract scarring, ejaculate size, mating behaviour, fitness of experimental females mated to stock males or fitness of stock females mated to experimental males. We suggest that this is likely due to insufficient strength of kin selection rather than a lack of genetic variation or time for selection. Limited dispersal alone is therefore not sufficient for kin selection to reduce male harmfulness in this species, consistent with general predictions that limited dispersal will only allow kin selection if local relatedness is independent of the intensity of competition among kin.}, }
@article {pmid32220095, year = {2020}, author = {Smith, NMA and Yagound, B and Remnant, EJ and Foster, CSP and Buchmann, G and Allsopp, MH and Kent, CF and Zayed, A and Rose, SA and Lo, K and Ashe, A and Harpur, BA and Beekman, M and Oldroyd, BP}, title = {Paternally-biased gene expression follows kin-selected predictions in female honey bee embryos.}, journal = {Molecular ecology}, volume = {29}, number = {8}, pages = {1523-1533}, doi = {10.1111/mec.15419}, pmid = {32220095}, issn = {1365-294X}, mesh = {Alleles ; Animals ; Bees/genetics ; Female ; Gene Expression ; *Genomic Imprinting ; Male ; Phenotype ; *Reproduction ; }, abstract = {The Kinship Theory of Genomic Imprinting (KTGI) posits that, in species where females mate with multiple males, there is selection for a male to enhance the reproductive success of his offspring at the expense of other males and his mating partner. Reciprocal crosses between honey bee subspecies show parent-of-origin effects for reproductive traits, suggesting that males modify the expression of genes related to female function in their female offspring. This effect is likely to be greater in the Cape honey bee (Apis mellifera capensis), because a male's daughters have the unique ability to produce female offspring that can develop into reproductive workers or the next queen without mating. We generated reciprocal crosses between Capensis and another subspecies and used RNA-seq to identify transcripts that are over- or underexpressed in the embryos, depending on the parental origin of the gene. As predicted, 21 genes showed expression bias towards the Capensis father's allele in colonies with a Capensis father, with no such bias in the reciprocal cross. A further six genes showed a consistent bias towards expression of the father's allele across all eight colonies examined, regardless of the direction of the cross. Consistent with predictions of the KTGI, six of the 21 genes are associated with female reproduction. No gene consistently showed overexpression of the maternal allele.}, }
@article {pmid32216664, year = {2020}, author = {Lehmann, L and Rousset, F}, title = {When Do Individuals Maximize Their Inclusive Fitness?.}, journal = {The American naturalist}, volume = {195}, number = {4}, pages = {717-732}, doi = {10.1086/707561}, pmid = {32216664}, issn = {1537-5323}, mesh = {Adaptation, Biological/*genetics ; Biological Evolution ; *Genetic Fitness ; Genetics, Population ; *Models, Genetic ; Selection, Genetic ; }, abstract = {Adaptation is often described in behavioral ecology as individuals maximizing their inclusive fitness. Under what conditions does this hold, and how does this relate to the gene-centered perspective of adaptation? We unify and extend the literature on these questions to class-structured populations. We demonstrate that the maximization (in the best-response sense) of class-specific inclusive fitness obtains in uninvadable population states (meaning that all deviating mutants become extinct). This defines a genuine actor-centered perspective on adaptation. But this inclusive fitness is assigned to all bearers of a mutant allele in a given class and depends on distributions of demographic and genetic contexts. These distributions, in turn, usually depend on events in previous generations and are thus not under individual control. This prevents, in general, envisioning individuals themselves as autonomous fitness maximizers, each with its own inclusive fitness. For weak selection, however, the dependence on earlier events can be neglected. We then show that each individual in each class appears to maximize its own inclusive fitness when all other individuals exhibit inclusive fitness-maximizing behavior. This defines a genuine individual-centered perspective of adaptation and justifies formally, as a first-order approximation, the long-heralded view of individuals appearing to maximize their own inclusive fitness.}, }
@article {pmid32210525, year = {2020}, author = {Gerber, L and Connor, RC and King, SL and Allen, SJ and Wittwer, S and Bizzozzero, MR and Friedman, WR and Kalberer, S and Sherwin, WB and Wild, S and Willems, EP and Krützen, M}, title = {Affiliation history and age similarity predict alliance formation in adult male bottlenose dolphins.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {31}, number = {2}, pages = {361-370}, pmid = {32210525}, issn = {1045-2249}, abstract = {Male alliances are an intriguing phenomenon in the context of reproduction since, in most taxa, males compete over an indivisible resource, female fertilization. Adult male bottlenose dolphins (Tursiops aduncus) in Shark Bay, Western Australia, form long-term, multilevel alliances to sequester estrus females. These alliances are therefore critical to male reproductive success. Yet, the long-term processes leading to the formation of such complex social bonds are still poorly understood. To identify the criteria by which male dolphins form social bonds with other males, we adopted a long-term approach by investigating the ontogeny of alliance formation. We followed the individual careers of 59 males for 14 years while they transitioned from adolescence (8-14 years of age) to adulthood (15-21 years old). Analyzing their genetic relationships and social associations in both age groups, we found that the vast majority of social bonds present in adolescence persisted through time. Male associations in early life predict alliance partners as adults. Kinship patterns explained associations during adolescence but not during adulthood. Instead, adult males associated with males of similar age. Our findings suggest that social bonds among peers, rather than kinship, play a central role in the development of adult male polyadic cooperation in dolphins.}, }
@article {pmid32203476, year = {2020}, author = {Daniel, MJ and Williamson, RJ}, title = {Males optimally balance selfish and kin-selected strategies of sexual competition in the guppy.}, journal = {Nature ecology &amp; evolution}, volume = {4}, number = {5}, pages = {745-752}, pmid = {32203476}, issn = {2397-334X}, mesh = {Animals ; Female ; Male ; *Poecilia ; Reproduction ; Sexual Behavior, Animal ; }, abstract = {Resolving the strategies by which organisms compete for limited resources is key to understanding behavioural and social evolution. When competing for matings, males in many species allocate mating effort preferentially towards higher-quality females. How males balance this against avoiding competition with rival males, who should also prefer high-quality females, is poorly understood. Kin selection theory further complicates these dynamics: males should avoid competition with close relatives especially because of added, indirect fitness costs. However, whether between-male relatedness modulates the intensity of intrasexual competition is equivocal. Here, we develop and test an analytical model describing how males should optimally allocate their mating efforts in response to information about differences in female quality, competitor presence/absence and competitor relatedness. Using freely interacting groups of Trinidadian guppies (Poecilia reticulata), we show concordance between observed and predicted mating effort allocation across all combinations of these factors. Thus, male mating effort is sensitive to variation in female quality, competitor presence and competitor relatedness, which is consistent with a kin-selected strategy of male-male competition. The fit of our model's predictions demonstrates that males integrate assessments of female quality and competitive context in a quantitatively meaningful way, implicating a competitive strategy that has been fine-tuned to maximize inclusive fitness gains.}, }
@article {pmid32183635, year = {2020}, author = {Faria, GS and Gardner, A}, title = {Does kin discrimination promote cooperation?.}, journal = {Biology letters}, volume = {16}, number = {3}, pages = {20190742}, pmid = {32183635}, issn = {1744-957X}, mesh = {Altruism ; *Biological Evolution ; Humans ; *Social Behavior ; }, abstract = {Genetic relatedness is a key driver of the evolution of cooperation. One mechanism that may ensure social partners are genetically related is kin discrimination, in which individuals are able to distinguish kin from non-kin and adjust their behaviour accordingly. However, the impact of kin discrimination upon the overall level of cooperation remains obscure. Specifically, while kin discrimination allows an individual to help more-related social partners over less-related social partners, it is unclear whether and how the population average level of cooperation that is evolutionarily favoured should differ under kin discrimination versus indiscriminate social behaviour. Here, we perform a general mathematical analysis in order to assess whether, when and in which direction kin discrimination changes the average level of cooperation in an evolving population. We find that kin discrimination may increase, decrease or leave unchanged the average level of cooperation, depending upon whether the optimal level of cooperation is a convex, concave or linear function of genetic relatedness. We develop an extension of the classic 'tragedy of the commons' model of cooperation in order to provide an illustration of these results. Our analysis provides a method to guide future research on the evolutionary consequences of kin discrimination.}, }
@article {pmid32183634, year = {2020}, author = {Kennedy, P and Radford, AN}, title = {Sibling quality and the haplodiploidy hypothesis.}, journal = {Biology letters}, volume = {16}, number = {3}, pages = {20190764}, pmid = {32183634}, issn = {1744-957X}, mesh = {Animals ; Bees ; *Biological Evolution ; Female ; Humans ; Male ; Models, Biological ; Sex Ratio ; *Siblings ; Social Behavior ; }, abstract = {The 'haplodiploidy hypothesis' argues that haplodiploid inheritance in bees, wasps, and ants generates relatedness asymmetries that promote the evolution of altruism by females, who are less related to their offspring than to their sisters ('supersister' relatedness). However, a consensus holds that relatedness asymmetry can only drive the evolution of eusociality if workers can direct their help preferentially to sisters over brothers, either through sex-ratio biases or a pre-existing ability to discriminate sexes among the brood. We show via a kin selection model that a simple feature of insect biology can promote the origin of workers in haplodiploids without requiring either condition. In insects in which females must found and provision new nests, body quality may have a stronger influence on female fitness than on male fitness. If altruism boosts the quality of all larval siblings, sisters may, therefore, benefit more than brothers from receiving the same amount of help. Accordingly, the benefits of altruism would fall disproportionately on supersisters in haplodiploids. Haplodiploid females should be more prone to altruism than diplodiploid females or males of either ploidy when altruism elevates female fitness especially, and even when altruists are blind to sibling sex.}, }
@article {pmid32180428, year = {2020}, author = {Tanskanen, AO and Danielsbacka, M and Rotkirch, A}, title = {Grandparental Childcare for Biological, Adopted, and Step-Offspring: Findings From Cross-National Surveys.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {18}, number = {1}, pages = {1474704920907894}, pmid = {32180428}, issn = {1474-7049}, support = {HHSN271201300071C/AG/NIA NIH HHS/United States ; }, mesh = {Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; *Adult Children/statistics &amp; numerical data ; *Child Rearing ; *Child, Adopted/statistics &amp; numerical data ; Europe ; *Grandparents ; *Intergenerational Relations ; }, abstract = {Based on kin selection theory, amounts of grandparental investment should reflect the probability to share common genes with offspring. Adoption may represent a special case, however, yet grandparental investment in adopted children has previously been both theoretically misconstrued and little investigated. Here, we study for the first time how grandparental childcare provision is distributed between biological, adopted, and step-offspring. Using Generations and Gender Surveys (n = 15,168 adult child-grandmother and 12,193 adult child-grandfather dyads) and the Survey of Health, Ageing, and Retirement in Europe (n = 17,233 grandmother-adult child and 13,000 grandfather-adult child dyads), we find that grandparents were less likely to provide care to stepchildren than to adopted and biological children, but no difference between adopted and biological children. These findings were present in both data sets and for both grandmothers and grandfathers, after several potentially confounding factors were taken into account. The stepchild disadvantage is in line with kin selection theory. The congruent amounts of care provided to adopted and biological children may reflect similar levels of adult-child attachment, selection effects, and greater need in adoptive families, as well as some degree of genetical relatedness in the case of kin adoption. The study provides new evidence of biased kin investments in contemporary societies and stresses the importance of psychological motivation and attachment in evolutionary studies of kin investment.}, }
@article {pmid32166391, year = {2020}, author = {Ruf, T and Bieber, C}, title = {Use of social thermoregulation fluctuates with mast seeding and reproduction in a pulsed resource consumer.}, journal = {Oecologia}, volume = {192}, number = {4}, pages = {919-928}, pmid = {32166391}, issn = {1432-1939}, support = {P 20534//Austrian Science Fund/ ; P 25023//Austrian Science Fund/ ; }, mesh = {Animals ; Body Temperature Regulation ; Female ; Horses ; Male ; *Myoxidae ; Reproduction ; Social Behavior ; }, abstract = {Edible dormice (Glis glis) can remain entirely solitary but frequently share sleeping sites with conspecifics in groups of up to 16 adults and yearlings. Here, we analysed grouping behaviour of 4564 marked individuals, captured in a 13-year study in nest boxes in a deciduous forest. We aimed to clarify (i) whether social thermoregulation is the primary cause for group formation and (ii) which factors affect group size and composition. Dormice temporarily formed both mixed and single-sex groups in response to acute cold ambient temperatures, especially those individuals with small body mass. Thus, thermoregulatory huddling appears to be the driving force for group formation in this species. Huddling was avoided-except for conditions of severe cold load-in years of full mast seeding, which is associated with reproduction and high foraging activity. Almost all females remained solitary during reproduction and lactation. Hence, entire populations of dormice switched between predominantly solitary lives in reproductive years to social behaviour in non-reproductive years. Non-social behaviour pointed to costs of huddling in terms of competition for local food resources even when food is generally abundant. The impact of competition was mitigated by a sex ratio that was biased towards males, which avoids sharing of food resources with related females that have extremely high energy demands during lactation. Importantly, dormice preferentially huddled in male-biased groups with litter mates from previous years. The fraction of related individuals increased with group size. Hence, group composition partly offsets the costs of shared food resources via indirect fitness benefits.}, }
@article {pmid32165158, year = {2020}, author = {Van Cleve, J}, title = {Building a synthetic basis for kin selection and evolutionary game theory using population genetics.}, journal = {Theoretical population biology}, volume = {133}, number = {}, pages = {65-70}, doi = {10.1016/j.tpb.2020.03.001}, pmid = {32165158}, issn = {1096-0325}, mesh = {*Biological Evolution ; *Game Theory ; Genetics, Population ; Population Dynamics ; Selection, Genetic ; }, }
@article {pmid32146892, year = {2020}, author = {Lehtonen, J}, title = {The Price equation and the unity of social evolution theory.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {375}, number = {1797}, pages = {20190362}, pmid = {32146892}, issn = {1471-2970}, mesh = {Animals ; *Biological Evolution ; Genetics, Population/*methods ; *Models, Genetic ; *Selection, Genetic ; *Social Evolution ; }, abstract = {The Price equation has been entangled with social evolution theory from the start. It has been used to derive the most general versions of kin selection theory, and Price himself produced a multilevel equation that provides an alternative formulation of social evolution theory, dividing selection into components between and within groups. In this sense, the Price equation forms a basis for both kin and group selection, so often pitted against each other in the literature. Contextual analysis and the neighbour approach are prominent alternatives for analysing group selection. I discuss these four approaches to social evolution theory and their connections to the Price equation, focusing on their similarities and common mathematical structure. Despite different notations and modelling traditions, all four approaches are ultimately linked by a common set of mathematical components, revealing their underlying unity in a transparent way. The Price equation can similarly be used in the derivation of streamlined, weak selection social evolution modelling methods. These weak selection models are practical and powerful methods for constructing models in evolutionary and behavioural ecology; they can clarify the causal structure of models, and can be easily converted between the four social evolution approaches just like their regression counterparts. This article is part of the theme issue 'Fifty years of the Price equation'.}, }
@article {pmid32123093, year = {2020}, author = {Criscione, CD and van Paridon, BJ and Gilleard, JS and Goater, CP}, title = {Clonemate cotransmission supports a role for kin selection in a puppeteer parasite.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {117}, number = {11}, pages = {5970-5976}, pmid = {32123093}, issn = {1091-6490}, mesh = {Animals ; Ants/parasitology/physiology ; Behavior, Animal ; *Biological Evolution ; Dicrocoelium/parasitology ; Host-Parasite Interactions/genetics/*physiology ; Larva ; Parasites/*physiology ; Pedigree ; Snails/parasitology ; Trematoda/genetics/physiology ; }, abstract = {Host manipulation by parasites is a fascinating evolutionary outcome, but adaptive scenarios that often accompany even iconic examples in this popular field of study are speculative. Kin selection has been invoked as a means of explaining the evolution of an altruistic-based, host-manipulating behavior caused by larvae of the lancet fluke Dicrocoelium dendriticum in ants. Specifically, cotransmission of larval clonemates from a snail first host to an ant second host is presumed to lead to a puppeteer parasite in the ant's brain that has clonemates in the ant abdomen. Clonal relatedness between the actor (brain fluke) and recipients (abdomen flukes) enables kin selection of the parasite's host-manipulating trait, which facilitates transmission of the recipients to the final host. However, the hypothesis that asexual reproduction in the snail leads to a high abundance of clonemates in the same ant is untested. Clonal relationships between the manipulator in the brain and the nonmanipulators in the abdomen are also untested. We provide empirical data on the lancet fluke's clonal diversity within its ant host. In stark contrast to other trematodes, which do not exhibit the same host-manipulating behavioral trait, the lancet fluke has a high abundance of clonemates. Moreover, our data support existing theory that indicates that the altruistic behavior can evolve even in the presence of multiple clones within the same ant host. Importantly, our analyses conclusively show clonemate cotransmission into ants, and, as such, we find support for kin selection to drive the evolution and maintenance of this iconic host manipulation.}, }
@article {pmid32117125, year = {2020}, author = {Kaundal, S and Deep, A and Kaur, G and Thakur, KG}, title = {Molecular and Biochemical Characterization of YeeF/YezG, a Polymorphic Toxin-Immunity Protein Pair From Bacillus subtilis.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {95}, pmid = {32117125}, issn = {1664-302X}, abstract = {Polymorphic toxins are important and widespread elements of bacterial warfare that help in restricting the growth of competitors, aiding kin selection, and shaping the bacterial communities. Although widespread, polymorphic toxin systems (PTS) have been extensively studied in Gram-negative bacteria, there are limited studies describing PTS in Gram-positive bacteria. The present study characterizes YeeF/YezG, a predicted member of a PF04740 family of the polymorphic toxin-immunity system from a Gram-positive bacteria Bacillus subtilis. The expression of the C-terminal toxic domain of YeeF (YeeF-CT) causes growth inhibition and gross morphological changes in Escherichia coli. The observed toxic effects are neutralized by the co-expression of yezG, a gene present downstream of yeeF, confirming YeeF-CT/YezG as a toxin/immunity protein pair. Biochemical and in vivo studies reveal that YeeF-CT causes toxicity due to its non-specific metal-dependent DNase activity. This is different from the previously reported RNase activity from the three B. subtilis toxins belonging to PF04740 family. Isothermal titration calorimetry (ITC) data analysis suggests that YeeF-CT binds YezG with a dissociation constant in the nanomolar range. Analytical ultracentrifugation studies revealed that YeeF-CT forms a homodimer and binds with two molecules of monomeric YezG immunity protein to form a 2:2 stochiometric heterotetrameric complex. Biolayer interferometry and electrophoretic mobility shift assays show that YeeF-CT/YezG/DNA forms a stable ternary complex implicating that YezG is an exosite inhibitor of YeeF-CT. This study extends the molecular targets of the toxins in the PF04740 family and thus, this family of toxins can be broadly classified as nucleases harboring either DNases or RNases activities.}, }
@article {pmid32108343, year = {2020}, author = {Stockmaier, S and Bolnick, DI and Page, RA and Carter, GG}, title = {Sickness effects on social interactions depend on the type of behaviour and relationship.}, journal = {The Journal of animal ecology}, volume = {89}, number = {6}, pages = {1387-1394}, doi = {10.1111/1365-2656.13193}, pmid = {32108343}, issn = {1365-2656}, mesh = {Animals ; *Chiroptera ; Food ; Grooming ; Social Behavior ; *Social Interaction ; }, abstract = {Infections can change social behaviour in multiple ways, with profound impacts on pathogen transmission. However, these impacts might depend on the type of behaviour, how sociality as a biological trait is defined (e.g. network degree vs. mean edge strength) and the type of social relationship between the interacting individuals. We used the highly social common vampire bat Desmodus rotundus to test how an immune challenge by lipopolysaccharide (LPS) injections affects two different social behaviours and three alternate measures of sociality, and whether the LPS effect differs by kinship relationship. Effects of sickness should be lower for social behaviours that bestow greater benefits to inclusive fitness, such as food sharing. As predicted, immune-challenged bats experienced a greater reduction in allogrooming received than food sharing received. Sickness effects might also depend on how a social interaction is defined (e.g. the number of grooming partners vs. the duration of grooming events). We predicted that sickness would impact both the number and duration of social encounters, but we only detected a decrease in the number of grooming partners. Finally, sickness effects might vary with social relationship type. We predicted that sickness effects should be smaller for interactions among close kin. As expected, the immune challenge had smaller effects on mother-offspring interactions. In conclusion, our results highlight the need to explicitly consider how the effects of sickness on social network structure can differ depending on the 'who, what, and how' of social interactions, because these factors are likely to influence how sickness behaviour alters pathogen transmission.}, }
@article {pmid32099082, year = {2020}, author = {Lobmaier, JS and Probst, F and Fischbacher, U and Wirthmüller, U and Knoch, D}, title = {Pleasant body odours, but not genetic similarity, influence trustworthiness in a modified trust game.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {3388}, pmid = {32099082}, issn = {2045-2322}, mesh = {Adult ; HLA Antigens/*genetics/metabolism ; Humans ; Linear Models ; Male ; *Smell ; Trust ; Young Adult ; }, abstract = {Identifying trustworthy partners is an important adaptive challenge for establishing mutually cooperative relationships. Previous studies have demonstrated a marked relationship between a person's attractiveness and his apparent trustworthiness (beauty premium). Kin selection theory, however, suggests that cues to kinship enhance trustworthiness. Here we directly tested predictions of the beauty premium and kin selection theory by using body odours as cues to trustworthiness. Body odours reportedly portray information about an individuals' genotype at the human leucocyte antigen system (HLA) and thus olfactory cues in body odours serve as a promising means for kin recognition. Ninety men played trust games in which they divided uneven sums of monetary units between two male trustees represented by their body odour and rated each body odour for pleasantness. Half of the odours came from HLA-similar men (suggesting closer kin) and half from HLA dissimilar men (suggesting non-kin). We found that the amount of money the players transferred was not related to HLA-similarity, but to the pleasantness of the trustee's body odour. By showing that people with more pleasant body odours are trusted more than people with unpleasant body odour we provide evidence for a "beauty-premium" that overrides any putative effect of kin.}, }
@article {pmid32097598, year = {2020}, author = {Poirotte, C and Charpentier, MJE}, title = {Unconditional care from close maternal kin in the face of parasites.}, journal = {Biology letters}, volume = {16}, number = {2}, pages = {20190869}, pmid = {32097598}, issn = {1744-957X}, mesh = {Animals ; Family ; Grooming ; *Parasites ; Primates ; Social Behavior ; }, abstract = {Several species mitigate relationships according to their conspecifics' parasite status. Yet, this defence strategy comes with the costs of depriving individuals from valuable social bonds. Animals therefore face a trade-off between the costs of pathogen exposure and the benefits of social relationships. According to the models of social evolution, social bonds are highly kin-biased. However, whether kinship mitigates social avoidance of contagious individuals has never been tested so far. Here, we build on previous research to demonstrate that mandrills (Mandrillus sphinx) modulate social avoidance of contagious individuals according to kinship: individuals do not avoid grooming their close maternal kin when contagious (parasitized with oro-faecally transmitted protozoa), although they do for more distant or non-kin. While individuals' parasite status has seldom been considered as a trait impacting social relationships in animals, this study goes a step beyond by showing that kinship balances the effect of health status on social behaviour in a non-human primate.}, }
@article {pmid37588371, year = {2020}, author = {Micheletti, AJC and Ruxton, GD and Gardner, A}, title = {The demography of human warfare can drive sex differences in altruism.}, journal = {Evolutionary human sciences}, volume = {2}, number = {}, pages = {e7}, pmid = {37588371}, issn = {2513-843X}, abstract = {Recent years have seen great interest in the suggestion that between-group aggression and within-group altruism have coevolved. However, these efforts have neglected the possibility that warfare - via its impact on demography - might influence human social behaviours more widely, not just those directly connected to success in war. Moreover, the potential for sex differences in the demography of warfare to translate into sex differences in social behaviour more generally has remained unexplored. Here, we develop a kin-selection model of altruism performed by men and women for the benefit of their groupmates in a population experiencing intergroup conflict. We find that warfare can promote altruistic, helping behaviours as the additional reproductive opportunities winners obtain in defeated groups decrease harmful competition between kin. Furthermore, we find that sex can be a crucial modulator of altruism, with there being a tendency for the sex that competes more intensely with relatives to behave more altruistically and for the sex that competes more intensely with non-relatives in defeated groups to receive more altruism. In addition, there is also a tendency for the less-dispersing sex to both give and receive more altruism. We discuss implications for our understanding of observed sex differences in cooperation in human societies.}, }
@article {pmid32064318, year = {2019}, author = {Kappeler, PM and Pozzi, L}, title = {Evolutionary transitions toward pair living in nonhuman primates as stepping stones toward more complex societies.}, journal = {Science advances}, volume = {5}, number = {12}, pages = {eaay1276}, pmid = {32064318}, issn = {2375-2548}, mesh = {Animals ; Behavior, Animal ; *Biological Evolution ; Evolution, Molecular ; Phylogeny ; *Primates/classification/genetics ; Sexual Behavior, Animal ; *Social Behavior ; }, abstract = {Nonhuman primate societies vary tremendously in size and composition, but how and why evolutionary transitions among different states occurred remains highly controversial. In particular, how many times pair living evolved and the social states of the ancestors of pair- and group-living species remains contentious. We examined evolutionary transitions in primate social evolution by using new, independent categorizations of sociality and different phylogenetic hypotheses with a vastly expanded dataset. Using Bayesian phylogenetic comparative methods, we consistently found the strongest support for a model that invokes frequent transitions between solitary ancestors and pair-living descendants, with the latter giving rise to group-living species. This result was robust to systematic variation in social classification, sample size, and phylogeny. Our analyses therefore indicate that pair living was a stepping stone in the evolution of structurally more complex primate societies, a result that bolsters the role of kin selection in social evolution.}, }
@article {pmid32055412, year = {2020}, author = {Patel, M and West, SA and Biernaskie, JM}, title = {Kin discrimination, negative relatedness, and how to distinguish between selfishness and spite.}, journal = {Evolution letters}, volume = {4}, number = {1}, pages = {65-72}, pmid = {32055412}, issn = {2056-3744}, support = {BB/M011224/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, abstract = {Spiteful behaviors occur when an actor harms its own fitness to inflict harm on the fitness of others. Several papers have predicted that spite can be favored in sufficiently small populations, even when the harming behavior is directed indiscriminately at others. However, it is not clear that truly spiteful behavior could be favored without the harm being directed at a subset of social partners with relatively low genetic similarity to the actor (kin discrimination, causing a negative relatedness between actor and harmed recipient). Using mathematical models, we show that (1) the evolution of spite requires kin discrimination; (2) previous models suggesting indiscriminate spite involve scenarios where the actor gains a direct feedback benefit from harming others, and so the harming is selfish rather than spiteful; (3) extreme selfishness can be favored in small populations (or, more generally, under local competition) because this is where the direct feedback benefit of harming is greatest.}, }
@article {pmid31964305, year = {2020}, author = {Montazeaud, G and Rousset, F and Fort, F and Violle, C and Fréville, H and Gandon, S}, title = {Farming plant cooperation in crops.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1919}, pages = {20191290}, pmid = {31964305}, issn = {1471-2954}, mesh = {*Agriculture ; Biological Evolution ; Crops, Agricultural/*genetics ; Domestication ; Farms ; Phenotype ; Selection, Genetic ; }, abstract = {Selection of the fittest can promote individual competitiveness but often results in the erosion of group performance. Recently, several authors revisited this idea in crop production and proposed new practices based on selection for cooperative phenotypes, i.e. phenotypes that increase crop yield through decreased competitiveness. These recommendations, however, remain difficult to evaluate without a formal description of crop evolutionary dynamics under different selection strategies. Here, we develop a theoretical framework to investigate the evolution of cooperation-related traits in crops, using plant height as a case study. Our model is tailored to realistic agricultural practices and shows that combining high plant density, high relatedness and selection among groups favours the evolution of shorter plants that maximize grain yield. Our model allows us to revisit past and current breeding practices in light of kin selection theory, and yields practical recommendations to increase cooperation among crops and promote sustainable agriculture.}, }
@article {pmid31945069, year = {2020}, author = {Komatsu, H and Kubota, H and Tanaka, N and Ohashi, H}, title = {Designing information provision to serve as a reminder of altruistic benefits: A case study of the risks of air pollution caused by industrialization.}, journal = {PloS one}, volume = {15}, number = {1}, pages = {e0227024}, pmid = {31945069}, issn = {1932-6203}, mesh = {Adult ; Air Pollution/*adverse effects ; *Altruism ; Attitude ; Family/psychology ; Humans ; *Industrial Development ; Internet ; Middle Aged ; *Risk Assessment ; Surveys and Questionnaires ; }, abstract = {A well-known phenomenon is that humans perceive risks to threaten future generations as more dangerous in many cases. However, this tendency could be changed depending on certain conditions and could potentially be explained by the evolution of altruism. Our multi-agent simulation model, which was constructed to identify attributes contributing to subjective assessment of a risk source based on kin selection theory, showed that support from relatives can affect the agents' subjective risk assessment. We utilize this insight, which has never been explored in the context of nudge, to show that real-world messages reminding respondents that they are supported by their relatives can moderate the perception of a risk source as extremely dangerous. A randomized control trial based on an internet questionnaire survey was conducted to identify the intervention effect of such messages, using air pollution caused by industrialization as the risk source for the case study. Our analysis suggests that messages moderate extreme attitudes. Presentation of additional visual information can boost the sense of familial support and increase the effect of a message compared with a message comprising only textual information. The attributes and personality traits of the respondents who are responsive to the intervention message are also discussed.}, }
@article {pmid31928868, year = {2020}, author = {Brucks, D and von Bayern, AMP}, title = {Parrots Voluntarily Help Each Other to Obtain Food Rewards.}, journal = {Current biology : CB}, volume = {30}, number = {2}, pages = {292-297.e5}, doi = {10.1016/j.cub.2019.11.030}, pmid = {31928868}, issn = {1879-0445}, mesh = {Animals ; Behavior, Animal ; Female ; Food ; Male ; *Parrots ; *Reward ; *Social Behavior ; Species Specificity ; }, abstract = {Helping others to obtain benefits, even at a cost to oneself, poses an evolutionary puzzle [1]. While kin selection explains such "selfless" acts among relatives, only reciprocity (paying back received favors) entails fitness benefits for unrelated individuals [2]. So far, experimental evidence for both prosocial helping (providing voluntary assistance for achieving an action-based goal) and reciprocity has been reported in a few mammals but no avian species [3]. In order to gain insights into the evolutionary origins of these behaviors, the capacity of non-mammalian species for prosociality and for reciprocity needs to be investigated. We tested two parrot species in an instrumental-helping paradigm involving "token transfer." Here, actors could provide tokens to their neighbor, who could exchange them with an experimenter for food. To verify whether the parrots understood the task's contingencies, we systematically varied the presence of a partner and the possibility for exchange. We found that African grey parrots voluntarily and spontaneously transferred tokens to conspecific partners, whereas significantly fewer transfers occurred in the control conditions. Transfers were affected by the strength of the dyads' affiliation and partially by the receivers' attention-getting behaviors. Furthermore, the birds reciprocated the help once the roles were reversed. Blue-headed macaws, in contrast, transferred hardly any tokens. Species differences in social tolerance might explain this discrepancy. These findings show that instrumental helping based on a prosocial attitude, accompanied but potentially not sustained by reciprocity, is present in parrots, suggesting that this capacity evolved convergently in this avian group and mammals.}, }
@article {pmid31897909, year = {2020}, author = {Chaves, &#xd3;M and Martins, V and Camaratta, D and Bicca-Marques, JC}, title = {Successful adoption of an orphan infant in a wild group of brown howler monkeys.}, journal = {Primates; journal of primatology}, volume = {61}, number = {2}, pages = {301-307}, pmid = {31897909}, issn = {1610-7365}, support = {PQ # 303154/2009-8, 303306/2013-0 and 304475/2018-1//Brazilian National Research Council/ ; 2755/2010//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; 1464332//Coordena&#xe7;&#xe3;o de Aperfei&#xe7;oamento de Pessoal de N&#xed;vel Superior/ ; }, mesh = {Alouatta/*physiology ; Animal Nutritional Physiological Phenomena ; Animals ; Brazil ; Diet/veterinary ; Feeding Behavior ; Female ; Lactation ; Male ; *Maternal Behavior ; Plant Leaves ; }, abstract = {The rarity of infant adoption in wild primates compromises our understanding of its consequences for the participating individuals. We report the first case of successful infant adoption in a wild group of brown howler monkeys (Alouatta guariba clamitans). We evaluated the potential costs of the behavior for the adoptive mother by comparing her activity budget and diet before and after the adoption. On 18 June 2013, a domestic dog killed the mother of a 2-month-old male infant (Victorio) as she attempted to cross a canopy gap. Victorio was immediately rescued from her belly by a researcher and released in a climber near another infant-carrying female (Sofia, his likely grandmother). Sofia recovered him 2 min later. She carried and breastfed both infants during the next 4 weeks, when her own infant disappeared. We monitored Victorio until he reached adulthood in March 2018. Sofia fed more (mainly on immature leaves) when she nursed only Victorio than when nursing only her own or both infants. Assuming that the disappearance of Sofia's own infant was unrelated to the adoption of Victorio, we conclude that his successful adoption may contribute to Sofia's inclusive fitness if he sires his own infants.}, }
@article {pmid31833181, year = {2020}, author = {Martinig, AR and McAdam, AG and Dantzer, B and Lane, JE and Coltman, DW and Boutin, S}, title = {The new kid on the block: immigrant males win big whereas females pay fitness cost after dispersal.}, journal = {Ecology letters}, volume = {23}, number = {3}, pages = {430-438}, doi = {10.1111/ele.13436}, pmid = {31833181}, issn = {1461-0248}, mesh = {Breeding ; Canada ; *Emigrants and Immigrants ; Female ; Humans ; Male ; *Reproduction ; }, abstract = {Dispersal is nearly universal; yet, which sex tends to disperse more and their success thereafter depends on the fitness consequences of dispersal. We asked if lifetime fitness differed between residents and immigrants (successful between-population dispersers) and their offspring using 29 years of monitoring from North American red squirrels (Tamiasciurus hudsonicus) in Canada. Compared to residents, immigrant females had 23% lower lifetime breeding success (LBS), while immigrant males had 29% higher LBS. Male immigration and female residency were favoured. Offspring born to immigrants had 15-43% lower LBS than offspring born to residents. We conclude that immigration benefitted males, but not females, which appeared to be making the best of a bad lot. Our results are in line with male-biased dispersal being driven by local mate competition and local resource enhancement, while the intergenerational cost to immigration is a new complication in explaining the drivers of sex-biased dispersal.}, }
@article {pmid31818941, year = {2019}, author = {Nattrass, S and Croft, DP and Ellis, S and Cant, MA and Weiss, MN and Wright, BM and Stredulinsky, E and Doniol-Valcroze, T and Ford, JKB and Balcomb, KC and Franks, DW}, title = {Postreproductive killer whale grandmothers improve the survival of their grandoffspring.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {52}, pages = {26669-26673}, pmid = {31818941}, issn = {1091-6490}, abstract = {Understanding why females of some mammalian species cease ovulation prior to the end of life is a long-standing interdisciplinary and evolutionary challenge. In humans and some species of toothed whales, females can live for decades after stopping reproduction. This unusual life history trait is thought to have evolved, in part, due to the inclusive fitness benefits that postreproductive females gain by helping kin. In humans, grandmothers gain inclusive fitness benefits by increasing their number of surviving grandoffspring, referred to as the grandmother effect. Among toothed whales, the grandmother effect has not been rigorously tested. Here, we test for the grandmother effect in killer whales, by quantifying grandoffspring survival with living or recently deceased reproductive and postreproductive grandmothers, and show that postreproductive grandmothers provide significant survival benefits to their grandoffspring above that provided by reproductive grandmothers. This provides evidence of the grandmother effect in a nonhuman menopausal species. By stopping reproduction, grandmothers avoid reproductive conflict with their daughters, and offer increased benefits to their grandoffspring. The benefits postreproductive grandmothers provide to their grandoffspring are shown to be most important in difficult times where the salmon abundance is low to moderate. The postreproductive grandmother effect we report, together with the known costs of late-life reproduction in killer whales, can help explain the long postreproductive life spans of resident killer whales.}, }
@article {pmid31805037, year = {2019}, author = {Thomas, F and Giraudeau, M and Renaud, F and Ujvari, B and Roche, B and Pujol, P and Raymond, M and Lemaitre, JF and Alvergne, A}, title = {Can postfertile life stages evolve as an anticancer mechanism?.}, journal = {PLoS biology}, volume = {17}, number = {12}, pages = {e3000565}, pmid = {31805037}, issn = {1545-7885}, mesh = {Adaptation, Physiological/*physiology ; Animals ; Biological Evolution ; Female ; Humans ; Menopause/metabolism/*physiology ; Neoplasms/physiopathology/*prevention &amp; control ; Reproduction/physiology ; }, abstract = {Why a postfertile stage has evolved in females of some species has puzzled evolutionary biologists for over 50 years. We propose that existing adaptive explanations have underestimated in their formulation an important parameter operating both at the specific and the individual levels: the balance between cancer risks and cancer defenses. During their life, most multicellular organisms naturally accumulate oncogenic processes in their body. In parallel, reproduction, notably the pregnancy process in mammals, exacerbates the progression of existing tumors in females. When, for various ecological or evolutionary reasons, anticancer defenses are too weak, given cancer risk, older females could not pursue their reproduction without triggering fatal metastatic cancers, nor even maintain a normal reproductive physiology if the latter also promotes the growth of existing oncogenic processes, e.g., hormone-dependent malignancies. At least until stronger anticancer defenses are selected for in these species, females could achieve higher inclusive fitness by ceasing their reproduction and/or going through menopause (assuming that these traits are easier to select than anticancer defenses), thereby limiting the risk of premature death due to metastatic cancers. Because relatively few species experience such an evolutionary mismatch between anticancer defenses and cancer risks, the evolution of prolonged life after reproduction could also be a rare, potentially transient, anticancer adaptation in the animal kingdom.}, }
@article {pmid31795864, year = {2019}, author = {Gow, EA and Arcese, P and Dagenais, D and Sardell, RJ and Wilson, S and Reid, JM}, title = {Testing predictions of inclusive fitness theory in inbreeding relatives with biparental care.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1916}, pages = {20191933}, pmid = {31795864}, issn = {1471-2954}, mesh = {Animals ; Female ; *Inbreeding ; Male ; Passeriformes/*physiology ; *Sexual Behavior, Animal ; }, abstract = {Inclusive fitness theory predicts that parental care will vary with relatedness between potentially caring parents and offspring, potentially shaping mating system evolution. Systems with extra-pair paternity (EPP), and hence variable parent-brood relatedness, provide valuable opportunities to test this prediction. However, existing theoretical and empirical studies assume that a focal male is either an offspring's father with no inbreeding, or is completely unrelated. We highlight that this simple dichotomy does not hold given reproductive interactions among relatives, complicating the effect of EPP on parent-brood relatedness yet providing new opportunities to test inclusive fitness theory. Accordingly, we tested hierarchical hypotheses relating parental feeding rate to parent-brood relatedness, parent kinship and inbreeding, using song sparrows (Melospiza melodia) experiencing natural variation in relatedness. As predicted, male and female feeding rates increased with relatedness to a dependent brood, even controlling for brood size. Male feeding rate tended to decrease as paternity loss increased, and increased with increasing kinship and hence inbreeding between socially paired mates. We thereby demonstrate that variation in a key component of parental care concurs with subtle predictions from inclusive fitness theory. We additionally highlight that such effects can depend on the underlying social mating system, potentially generating status-specific costs of extra-pair reproduction.}, }
@article {pmid31790440, year = {2019}, author = {Fumagalli, SE and Rice, SH}, title = {Stochasticity and non-additivity expose hidden evolutionary pathways to cooperation.}, journal = {PloS one}, volume = {14}, number = {12}, pages = {e0225517}, pmid = {31790440}, issn = {1932-6203}, mesh = {Animals ; Behavior, Animal ; *Biological Evolution ; *Cooperative Behavior ; *Models, Biological ; Stochastic Processes ; }, abstract = {Cooperation is widespread across the tree of life, with examples ranging from vertebrates to lichens to multispecies biofilms. The initial evolution of such cooperation is likely to involve interactions that produce non-additive fitness effects among small groups of individuals in local populations. However, most models for the evolution of cooperation have focused on genealogically related individuals, assume that the factors influencing individual fitness are deterministic, that populations are very large, and that the benefits of cooperation increase linearly with the number of cooperative interactions. Here we show that stochasticity and non-additive interactions can facilitate the evolution of cooperation in small local groups. We derive a generalized model for the evolution of cooperation and show that if cooperation reduces the variance in individual fitness (separate from its effect on average fitness), this can aid in the evolution of cooperation through directional stochastic effects. In addition, we show that the potential for the evolution of cooperation is influenced by non-additivity in benefits with cooperation being more likely to evolve when the marginal benefit of a cooperative act increases with the number of such acts. Our model compliments traditional cooperation models (kin selection, reciprocal cooperation, green beard effect, etc.) and applies to a broad range of cooperative interactions seen in nature.}, }
@article {pmid31729694, year = {2019}, author = {Clech, L and Hazel, A and Gibson, MA}, title = {Does Kin-Selection Theory Help to Explain Support Networks among Farmers in South-Central Ethiopia?.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {30}, number = {4}, pages = {422-447}, pmid = {31729694}, issn = {1936-4776}, support = {F/00182/BI//Leverhulme Trust Research Grant/ ; }, mesh = {Adult ; *Birth Order ; *Competitive Behavior ; Ethiopia/ethnology ; Family Relations/*ethnology ; *Farmers ; Humans ; Psychological Theory ; *Psychosocial Support Systems ; Sibling Relations/ethnology ; }, abstract = {Social support networks play a key role in human livelihood security, especially in vulnerable communities. Here we explore how evolutionary ideas of kin selection and intrahousehold resource competition can explain individual variation in daily support network size and composition in a south-central Ethiopian agricultural community. We consider both domestic and agricultural help across two generations with different wealth-transfer norms that yield different contexts for sibling competition. For farmers who inherited land rights from family, firstborns were more likely to report daily support from parents and to have larger nonparental kin networks (n = 180). Compared with other farmers, firstborns were also more likely to reciprocate their parents' support, and to help nonparental kin without reciprocity. For farmers who received land rights from the government (n = 151), middle-born farmers reported more nonparental kin in their support networks compared with other farmers; nonreciprocal interactions were particularly common in both directions. This suggests a diversification of adult support networks to nonparental kin, possibly in response to a long-term parental investment disadvantage of being middle-born sons. In all instances, regardless of inheritance, lastborn farmers were the most disadvantaged in terms of kin support. Overall, we found that nonreciprocal interactions among farmers followed kin selection predictions. Direct reciprocity explained a substantial part of the support received from kin, suggesting the importance of the combined effects of kin selection and reciprocity for investment from kin.}, }
@article {pmid31729693, year = {2019}, author = {Boesch, L and Berger, R}, title = {Explaining Fairness : Results from an Experiment in Guinea.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {30}, number = {4}, pages = {398-421}, pmid = {31729693}, issn = {1936-4776}, mesh = {Adult ; Family/*ethnology ; *Group Processes ; Guinea/ethnology ; Humans ; *Morals ; *Social Behavior ; *Social Perception ; }, abstract = {Fairness is undoubtedly an essential normative concept in humans and promotes cooperation in human societies. The fact that fairness exists is puzzling, however, because it works against the short-term interest of individuals. Theories of genetic evolution, cultural evolution, and gene-culture coevolution identify plausible mechanisms for the evolution of fairness in humans. Such mechanisms include kin selection, the support of group-beneficial moral norms through ethnic markers, free partner choice with equal outside options, and free partner choice with reputation as well as spite in small populations. Here, we present the results of a common-pool resource game experiment on sharing. Based on data from 37 multiethnic villages in a subsistence agricultural population in Foutah Djallon, Guinea, we show that fair behavior in our experiment increased with increasing ethnic homogeneity and market integration. Group size and kinship had the opposite effect. Overall, fair behavior was not conditional on reputation. Instead, the ability of the different village populations to support individuals' fairness in situations lacking the opportunity to build a positive reputation varied significantly. Our results suggest that evolutionary theory provides a useful framework for the analysis of fairness in humans.}, }
@article {pmid31713849, year = {2020}, author = {Winnicki, SK and Munguía, SM and Williams, EJ and Boyle, WA}, title = {Social interactions do not drive territory aggregation in a grassland songbird.}, journal = {Ecology}, volume = {101}, number = {2}, pages = {e02927}, doi = {10.1002/ecy.2927}, pmid = {31713849}, issn = {1939-9170}, support = {DBI-140802//Kansas State University (KSU) Biology National Science Foundation (NSF) REU Program/International ; //EPSCoR 1st Award/International ; DEB-175449//NSF/International ; //NSF Graduate Research Fellowship/International ; //Sigma Xi Grant-in-Aid of Research/International ; //Kansas Ornithological Society/International ; }, mesh = {Animals ; Ecosystem ; Grassland ; Interpersonal Relations ; Male ; *Passeriformes ; *Songbirds ; }, abstract = {Understanding the drivers of animal distributions is a fundamental goal of ecology and informs habitat management. The costs and benefits of colonial aggregations in animals are well established, but the factors leading to aggregation in territorial animals remain unclear. Territorial animals might aggregate to facilitate social behavior such as (1) group defense from predators and/or parasites, (2) cooperative care of offspring, (3) extra-pair mating, and/or (4) mitigating costs of extra-pair mating through kin selection. Using experimental and observational methods, we tested predictions of all four hypotheses in a tallgrass prairie in northeast Kansas, United States. Grasshopper Sparrow (Ammodramus savannarum) males formed clumps of territories in some parts of the site while leaving other apparently suitable areas unoccupied. Despite substantial sampling effort (653 territories and 223 nests), we found no support for any hypothesized social driver of aggregation, nor evidence that aggregation increases nest success. Our results run counter to previous evidence that conspecific interactions shape territory distributions. These results suggest one of the following alternatives: (1) the benefits of aggregation accrue to different life-history stages, or (2) the benefits of territory aggregation may be too small to detect in short-term studies and/or the consequences of aggregation are sufficiently temporally and spatially variable that they do not always appear to be locally adaptive, perhaps exacerbated by changing landscape contexts and declining population sizes.}, }
@article {pmid31690488, year = {2020}, author = {Paternotte, C}, title = {Social evolution and the individual-as-maximising-agent analogy.}, journal = {Studies in history and philosophy of biological and biomedical sciences}, volume = {79}, number = {}, pages = {101225}, doi = {10.1016/j.shpsc.2019.101225}, pmid = {31690488}, issn = {1879-2499}, mesh = {*Biological Evolution ; *Genetic Fitness ; Models, Biological ; Models, Genetic ; *Selection, Genetic ; *Social Behavior ; }, abstract = {Does natural selection tend to maximise something? Does it produce individuals who act as if they maximised something? These questions have long occupied evolutionary theorists, and have proven especially tricky in the case of social evolution, which is known for leading to apparently suboptimal states. This paper investigates recent results about maximising analogies - especially regarding whether individuals should be considered as if they maximised their inclusive fitness - and compares the fruitfulness of global and local approaches. I assess Okasha &amp; Martens's recent local approach to the individual-as-maximising-agent analogy and its robustness with respect to interactive situations. I then defend the relative merits of a comparable global approach, arguing that it is conceptually on a par and heuristically advantageous.}, }
@article {pmid31650630, year = {2020}, author = {Keaney, TA and Wong, HWS and Dowling, DK and Jones, TM and Holman, L}, title = {Mother's curse and indirect genetic effects: Do males matter to mitochondrial genome evolution?.}, journal = {Journal of evolutionary biology}, volume = {33}, number = {2}, pages = {189-201}, doi = {10.1111/jeb.13561}, pmid = {31650630}, issn = {1420-9101}, mesh = {Animals ; Drosophila melanogaster/*genetics ; Female ; Genome, Mitochondrial/*genetics ; Male ; *Maternal Inheritance ; Selection, Genetic ; }, abstract = {Maternal inheritance of mitochondrial DNA (mtDNA) was originally thought to prevent any response to selection on male phenotypic variation attributable to mtDNA, resulting in a male-biased mtDNA mutation load ("mother's curse"). However, the theory underpinning this claim implicitly assumes that a male's mtDNA has no effect on the fitness of females he comes into contact with. If such "mitochondrially encoded indirect genetics effects" (mtIGEs) do in fact exist, and there is relatedness between the mitochondrial genomes of interacting males and females, male mtDNA-encoded traits can undergo adaptation after all. We tested this possibility using strains of Drosophila melanogaster that differ in their mtDNA. Our experiments indicate that female fitness is influenced by the mtDNA carried by males that the females encounter, which could plausibly allow the mitochondrial genome to evolve via kin selection. We argue that mtIGEs are probably common, and that this might ameliorate or exacerbate mother's curse.}, }
@article {pmid31636937, year = {2019}, author = {Levin, SR and Caro, SM and Griffin, AS and West, SA}, title = {Honest signaling and the double counting of inclusive fitness.}, journal = {Evolution letters}, volume = {3}, number = {5}, pages = {428-433}, pmid = {31636937}, issn = {2056-3744}, abstract = {Inclusive fitness requires a careful accounting of all the fitness effects of a particular behavior. Verbal arguments can potentially exaggerate the inclusive fitness consequences of a behavior by including the fitness of relatives that was not caused by that behavior, leading to error. We show how this "double-counting" error can arise, with a recent example from the signaling literature. In particular, we examine the recent debate over whether parental divorce increases parent-offspring conflict, selecting for less honest signaling. We found that, when all the inclusive fitness consequences are accounted for, parental divorce increases conflict between siblings, in a way that they can select for less honest signaling. This prediction is consistent with the empirical data. More generally, our results illustrate how verbal arguments can be misleading, emphasizing the advantage of formal mathematical models.}, }
@article {pmid31629289, year = {2019}, author = {Swedell, L and Plummer, T}, title = {Social evolution in Plio-Pleistocene hominins: Insights from hamadryas baboons and paleoecology.}, journal = {Journal of human evolution}, volume = {137}, number = {}, pages = {102667}, doi = {10.1016/j.jhevol.2019.102667}, pmid = {31629289}, issn = {1095-8606}, mesh = {Animals ; *Biological Evolution ; Female ; Hominidae/*psychology ; Kenya ; Male ; Papio hamadryas/*psychology ; *Social Behavior ; }, abstract = {Reconstructions of hominin evolution have long benefited from comparisons with nonhuman primates, especially baboons and chimpanzees. The hamadryas baboon (Papio hamadryas) is arguably one of the best such models, as it exhibits both the male kin bonding and the cross-sex pair bonding thought to have been important in hominin evolution. Here we link processes of behavioral evolution in hamadryas baboons with those in a Plio-Pleistocene hominin, provisionally identified as Homo erectus (sensu lato) - a pivotal species in that its larger body and brain size and wider ranging patterns increased female costs of reproduction, increasing the importance of sociality. The combination of these higher costs of reproduction and shifts in diet and food acquisition have previously been argued to have been alleviated either via strengthening of male-female bonds (involving male provisioning and the evolution of monogamy) or via the assistance of older, post-reproductive females (leading to post-reproductive longevity in females, i.e., the grandmother hypothesis). We suggest that both arrangements could have been present in Plio-Pleistocene hominins if they lived in multilevel societies. Here we expand on our earlier scenario with two sets of recent data in support of it, (1) archaeological data from the 2 million year old Oldowan site of Kanjera South, Kenya and other sites that are suggestive of tool dependent foraging on nutrient dense resources (animal carcasses and plant underground storage organs), cooperation, and food sharing; and (2) a pattern of genetic variation in hamadryas baboons that suggests the operation of kin selection among both males and females at multiple levels of society. Taken together, these two sets of data strengthen our model and support the idea of a complex society linked by male-male, male-female, and female-female bonds at multiple levels of social organization in Plio-Pleistocene hominins.}, }
@article {pmid31624543, year = {2019}, author = {Nonacs, P}, title = {Reproductive skew in cooperative breeding: Environmental variability, antagonistic selection, choice, and control.}, journal = {Ecology and evolution}, volume = {9}, number = {18}, pages = {10163-10175}, pmid = {31624543}, issn = {2045-7758}, abstract = {A multitude of factors may determine reproductive skew among cooperative breeders. One explanation, derived from inclusive fitness theory, is that groups can partition reproduction such that subordinates do at least as well as noncooperative solitary individuals. The majority of recent data, however, fails to support this prediction; possibly because inclusive fitness models cannot easily incorporate multiple factors simultaneously to predict skew. Notable omissions are antagonistic selection (across generations, genes will be in both dominant and subordinate bodies), constraints on the number of sites suitable for successful reproduction, choice in which group an individual might join, and within-group control or suppression of competition. All of these factors and more are explored through agent-based evolutionary simulations. The results suggest the primary drivers for the initial evolution of cooperative breeding may be a combination of limited suitable sites, choice across those sites, and parental manipulation of offspring into helping roles. Antagonistic selection may be important when subordinates are more frequent than dominants. Kinship matters, but its main effect may be in offspring being available for manipulation while unrelated individuals are not. The greater flexibility of evolutionary simulations allows the incorporation of species-specific life histories and ecological constraints to better predict sociobiology.}, }
@article {pmid31616483, year = {2019}, author = {Deng, K and Liu, W and Wang, DH}, title = {Relatedness and spatial distance modulate intergroup interactions: experimental evidence from a social rodent.}, journal = {Current zoology}, volume = {65}, number = {5}, pages = {527-534}, pmid = {31616483}, issn = {1674-5507}, abstract = {Kin selection theory predicts that individuals should generally behave less aggressively or more amicably towards relatives than nonkin. However, how individuals treat conspecifics depends on genetic relatedness but also on the ecological context, which influences the benefits and costs of their interactions. In this study, we used microsatellite DNA markers and behavioral tests to examine the influence of kinship and proximity on the social behavior of Mongolian gerbils Meriones unguiculatus living in different social groups, and whether these effects varied with sex and season. We recorded the duration of 4 behavioral categories (investigative, neutral, amicable, and agonistic) during a 10-min pairwise test. We found that genetic relatedness had significant effects on the duration of investigative, neutral, and amicable behavior, but not on agonistic behavior. We also found significant interaction effects of relatedness and distance between burrow systems (i.e., spatial distance) on investigative, neutral, and amicable behavior, which suggests that the effects of kinship on social behavior were restricted by spatial proximity. The interaction effect between sex and relatedness on amicable behavior showed that male gerbils became more intimate with individuals of the same sex that had higher pairwise relatedness than females. Furthermore, both male and female gerbils enhanced their aggression during the food-hoarding season, but the intensity of these changes was significantly higher in females. Overall, our results suggest that the effects of kinship and spatial proximity on social behavior exhibit sexual or seasonal patterns, thereby implying ecological context-dependent responses to out-group individuals in Mongolian gerbils.}, }
@article {pmid31598313, year = {2019}, author = {Freeman, AR and Wood, TJ and Bairos-Novak, KR and Anderson, WG and Hare, JF}, title = {Gone girl: Richardson's ground squirrel offspring and neighbours are resilient to female removal.}, journal = {Royal Society open science}, volume = {6}, number = {9}, pages = {190904}, pmid = {31598313}, issn = {2054-5703}, abstract = {Within matrilineal societies, the presence of mothers and female kin can greatly enhance survival and reproductive success owing to kin-biased alarm calling, cooperation in territory defence, protection from infanticidal conspecifics, joint care of young and enhanced access to resources. The removal of mothers by predators or disease is expected to increase the stress experienced by offspring via activation of their hypothalamic-pituitary-adrenal axis, increasing circulating glucocorticoids and reducing offspring survival and reproductive success. Yet, few studies have removed mothers in the post-weaning period to examine the assumed physiological and fitness consequences associated with these mortality events. We examined how the loss of a mother affects juvenile Richardson's ground squirrels' (Urocitellus richardsonii) faecal glucocorticoid metabolites and their survival. Given that neighbours are often close kin, we further hypothesized that conspecific removal would similarly diminish the fitness of neighbouring individuals. Upon removing the mother, we detected no impact on offspring or neighbouring conspecific faecal glucocorticoid metabolites in the removal year, or on overwinter survival in the following year. Furthermore, no impact on neighbour reproductive success was detected. Given the high predation rates of ground squirrels in wild populations, resilience to a changing social environment would prove adaptive for both surviving kin and non-kin.}, }
@article {pmid31578780, year = {2019}, author = {Hervey, SD and Barnas, AF and Stechmann, TJ and Rockwell, RF and Ellis-Felege, SN and Darby, BJ}, title = {Kin grouping is insufficient to explain the inclusive fitness gains of conspecific brood parasitism in the common eider.}, journal = {Molecular ecology}, volume = {28}, number = {21}, pages = {4825-4838}, doi = {10.1111/mec.15258}, pmid = {31578780}, issn = {1365-294X}, mesh = {Animals ; Aquatic Organisms/genetics/parasitology ; Canada ; Ducks/genetics/*parasitology ; Female ; Genotype ; Host-Parasite Interactions/*genetics ; Nesting Behavior/physiology ; Reproduction/genetics ; Symbiosis/*genetics ; }, abstract = {Conspecific brood parasitism allows females to exploit other females' nests and enhance their reproductive output. Here, we test a recent theoretical model of how host females gain inclusive fitness from brood parasitism. High levels of relatedness between host and parasitizer can be maintained either by: (a) kin recognizing and parasitizing each other as a form of cooperative breeding or (b) natal philopatry and nest site fidelity facilitating the formation of kin groups, thereby increasing the probability of parasitism between relatives nesting in close proximity. To address these two hypotheses we genotyped feathers and hatch membranes of common eiders (Somateria mollissima) from western Hudson Bay, Canada, using a noninvasive sampling methodology. We found that most instances of brood parasitism do result in inclusive fitness gains. Furthermore, females with failed nests moved an average of 492 m from their previous year's nest site, while successful females only moved an average of 13 m. Therefore, we observed host-parasite relatedness can occur at levels higher than would be expected by chance even in the absence of kin grouping, suggesting that closely related females nesting near one another is not essential to maintain high host-parasitizer relatedness. In addition, kin grouping is only a transient phenomenon that cannot occur every year due to the propensity for females of failed nests to nest farther away from their nest site in subsequent years than females with successful nests, which provides support for kin recognition as a more likely mechanism to maintain high host-parasitizer relatedness over time.}, }
@article {pmid31548861, year = {2019}, author = {Fréville, H and Roumet, P and Rode, NO and Rocher, A and Latreille, M and Muller, MH and David, J}, title = {Preferential helping to relatives: A potential mechanism responsible for lower yield of crop variety mixtures?.}, journal = {Evolutionary applications}, volume = {12}, number = {9}, pages = {1837-1849}, pmid = {31548861}, issn = {1752-4571}, abstract = {Variety mixtures, the cultivation of different genotypes within a field, have been proposed as a way to increase within-crop diversity, allowing the development of more sustainable agricultural systems with reduced environmental costs. Although mixtures have often been shown to over-yield the average of component varieties in pure stands, decreased yields in mixtures have also been documented. Kin selection may explain such pattern, whenever plants direct helping behaviors preferentially toward relatives and thus experience stronger competition when grown with less related neighbors, lowering seed production of mixtures. Using varieties of durum wheat originating from traditional Moroccan agrosystems, we designed a greenhouse experiment to address whether plants reduced competition for light by limiting stem elongation when growing with kin and whether such phenotypic response resulted in higher yield of kin groups. Seeds were sown in groups of siblings and nonkin, each group containing a focal plant surrounded by four neighbors. At the group level, mean plant height and yield did not depend upon relatedness among competing plants. At the individual level, plant height was not affected by genetic relatedness to neighbors, after accounting for direct genetic effects that might induce among-genotype differences in the ability to capture resources that do not depend on relatedness. Moreover, in contrast to our predictions, shorter plants had lower inclusive fitness. Phenotypic plasticity in height was very limited in response to neighbor genotypes. This suggests that human selection in crops may have attenuated shade-avoidance responses to competition for light. Future research on preferential helping to relatives in crops might thus target social traits that drive competition for other resources than light. Overall, our study illustrates the relevance of tackling agricultural issues from an evolutionary standpoint and calls for extending such approaches to a larger set of crop species.}, }
@article {pmid31533478, year = {2019}, author = {Tanskanen, AO and Danielsbacka, M and Coall, DA and Jokela, M}, title = {Transition to Grandparenthood and Subjective Well-Being in Older Europeans: A Within-Person Investigation Using Longitudinal Data.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {17}, number = {3}, pages = {1474704919875948}, pmid = {31533478}, issn = {1474-7049}, support = {HHSN271201300071C/AG/NIA NIH HHS/United States ; }, mesh = {Aged ; Europe ; Female ; Grandparents/*psychology ; Humans ; *Intergenerational Relations ; Longitudinal Studies ; Male ; Middle Aged ; *Personal Satisfaction ; Quality of Life/*psychology ; }, abstract = {The transition to grandparenthood, that is the birth of the first grandchild, is often assumed to increase the subjective well-being of older adults; however, prior studies are scarce and have provided mixed results. Investigation of the associations between grandparenthood and subjective well-being, measured by self-rated life satisfaction, quality of life scores, and depressive symptoms, used the longitudinal Survey of Health, Ageing and Retirement in Europe from 13 countries, including follow-up waves between 2006 and 2015 (n = 64,940 person-observations from 38,456 unique persons of whom 18,207 had two or more measurement times). Both between-person and within-person (or fixed-effect) regression models were executed, where between-person associations represent results across individuals, that is, between grandparents and non-grandparents; within-person associations represent an individual's variation over time, that is, they consider whether the transition to grandparenthood increases or decreases subjective well-being. According to the between-person models, both grandmothers and grandfathers reported higher rate of life satisfaction and quality of life than non-grandparents. Moreover, grandmothers reported fewer depressive symptoms than women without grandchildren. The within-person models indicated that entry into grandmotherhood was associated with both improved quality of life scores and improved life satisfaction. These findings are discussed with reference to inclusive fitness theory, parental investment theory, and the grandmother hypothesis.}, }
@article {pmid31522939, year = {2019}, author = {Kalske, A and Shiojiri, K and Uesugi, A and Sakata, Y and Morrell, K and Kessler, A}, title = {Insect Herbivory Selects for Volatile-Mediated Plant-Plant Communication.}, journal = {Current biology : CB}, volume = {29}, number = {18}, pages = {3128-3133.e3}, doi = {10.1016/j.cub.2019.08.011}, pmid = {31522939}, issn = {1879-0445}, mesh = {Animals ; Cues ; Genotype ; Herbivory/*physiology ; Insecta/physiology ; Pheromones/metabolism/*physiology ; Plants/*chemistry/metabolism ; Solidago/metabolism ; Volatile Organic Compounds/chemistry ; }, abstract = {Plant volatile organic compounds (VOCs) are major vehicles of information transfer between organisms and mediate many ecological interactions [1-3]. Altering VOC emission in response to herbivore damage has been hypothesized to be adaptive, as it can deter subsequent herbivores [4], attract natural enemies of herbivores [5], or transmit information about attacks between distant parts of the same plant [6-9]. Neighboring plants may also respond to these VOC cues by priming their own defenses against oncoming herbivory, thereby reducing future damage [10-12]. However, under which conditions such information sharing provides fitness benefits to emitter plants, and, therefore, whether selection by herbivores affects the evolution of such VOC signaling, is still unclear [13]. Here, we test the predictions of two alternative hypotheses, the kin selection and mutual benefits hypotheses [14], to uncover the selective environment that may favor information sharing in plants. Measuring the response to natural selection in Solidago altissima, we found strong effects of herbivory on the way plants communicated with neighbors. Plants from populations that experienced selection by insect herbivory induced resistance in all neighboring conspecifics by airborne cues, whereas those from populations experiencing herbivore exclusion induced resistance only in neighbors of the same genotype. Furthermore, the information-sharing plants converged on a common, airborne VOC signal upon damage. We demonstrate that herbivory can drive the evolution of plant-plant communication via induction of airborne cues and suggest plants as a model system for understanding information sharing and communication among organisms in general.}, }
@article {pmid31506055, year = {2019}, author = {Berg, EC and Lind, MI and Monahan, S and Bricout, S and Maklakov, AA}, title = {Kin but less than kind: within-group male relatedness does not increase female fitness in seed beetles.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1910}, pages = {20191664}, pmid = {31506055}, issn = {1471-2954}, mesh = {Animals ; Coleoptera/*physiology ; Female ; Male ; Reproduction ; *Sexual Behavior, Animal ; }, abstract = {Theory maintains within-group male relatedness can mediate sexual conflict by reducing male-male competition and collateral harm to females. We tested whether male relatedness can lessen female harm in the seed beetle Callosobruchus maculatus. Male relatedness did not influence female lifetime reproductive success or individual fitness across two different ecologically relevant scenarios of mating competition. However, male relatedness marginally improved female survival. Because male relatedness improved female survival in late life when C. maculatus females are no longer producing offspring, our results do not provide support for the role of within-group male relatedness in mediating sexual conflict. The fact that male relatedness improves the post-reproductive part of the female life cycle strongly suggests that the effect is non-adaptive. We discuss adaptive and non-adaptive mechanisms that could result in reduced female harm in this and previous studies, and suggest that cognitive error is a likely explanation.}, }
@article {pmid31490727, year = {2019}, author = {Smith, AL and Atwater, DZ and Callaway, RM}, title = {Early Sibling Conflict May Ultimately Benefit the Family.}, journal = {The American naturalist}, volume = {194}, number = {4}, pages = {482-487}, doi = {10.1086/704773}, pmid = {31490727}, issn = {1537-5323}, mesh = {Aegilops/*growth &amp; development/physiology ; Fertilizers ; Seedlings/*growth &amp; development/physiology ; Seeds ; Soil ; }, abstract = {Relatives often interact differently with each other than with nonrelatives, and whether kin cooperate or compete has important consequences for the evolution of mating systems, seed size, dispersal, and competition. Previous research found that the larger of the size dimorphic seeds produced by the annual plant Aegilops triuncialis suppressed germination of their smaller sibs by 25%-60%. Here, we found evidence for kin recognition and sibling rivalry later in life among Aegilops seedlings that places seed-seed interactions in a broader context. In experiments with size dimorphic seeds, seedlings reduced the growth of sibling seedlings by ∼40% but that of nonsibling seedlings by ∼25%. These sequential antagonistic interactions between seeds and then seedlings provide insight into conflict and cooperation among kin. Kin-based conflict among seeds may maintain dormancy for some seeds until the coast is clear of more competitive siblings. If so, biotically induced seed dormancy may be a unique form of cooperation, which increases the inclusive fitness of maternal plants and offspring by minimizing competition among kin.}, }
@article {pmid31488327, year = {2019}, author = {Madgwick, PG and Belcher, LJ and Wolf, JB}, title = {Greenbeard Genes: Theory and Reality.}, journal = {Trends in ecology &amp; evolution}, volume = {34}, number = {12}, pages = {1092-1103}, doi = {10.1016/j.tree.2019.08.001}, pmid = {31488327}, issn = {1872-8383}, support = {BB/M01035X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {*Altruism ; *Biological Evolution ; Cooperative Behavior ; }, abstract = {Greenbeard genes were proposed as a cartoonish thought experiment to explain why altruism can be a selfish strategy from the perspective of genes. The likelihood of finding a real greenbeard gene in nature was thought to be remote because they were believed to require a set of improbable properties. Yet, despite this expectation, there is an ongoing explosion in claimed discoveries of greenbeard genes. Bringing together the latest theory and experimental findings, we argue that there is a need to dispose of the cartoon presentation of a greenbeard to refocus their burgeoning empirical study on the more fundamental concept that the thought experiment was designed to illustrate.}, }
@article {pmid31474495, year = {2019}, author = {Martens, J}, title = {Hamilton meets causal decision theory.}, journal = {Studies in history and philosophy of biological and biomedical sciences}, volume = {77}, number = {}, pages = {101187}, doi = {10.1016/j.shpsc.2019.101187}, pmid = {31474495}, issn = {1879-2499}, mesh = {*Altruism ; *Biological Evolution ; *Decision Theory ; *Genetic Fitness ; Models, Biological ; }, abstract = {In this paper, I contrast two mathematically equivalent ways of modeling the evolution of altruism, namely the classical inclusive fitness approach and a more recent, "direct fitness" approach. Though both are usually considered by evolutionists as mere different ways of representing the same causal process (i.e. that of kin selection), I argue that this consensus is misleading, for there is a fundamental ambiguity concerning the causal interpretation of the DF approach. Drawing on an analogy between the structure of inclusive fitness theory and that of causal decision theory (Stalnaker, 1972), I show that only the inclusive fitness framework can provide us with a proper, and unambiguous causal partition of the relevant variables involved in the evolution of altruism.}, }
@article {pmid31463010, year = {2019}, author = {Vostinar, AE and Goldsby, HJ and Ofria, C}, title = {Suicidal selection: Programmed cell death can evolve in unicellular organisms due solely to kin selection.}, journal = {Ecology and evolution}, volume = {9}, number = {16}, pages = {9129-9136}, pmid = {31463010}, issn = {2045-7758}, abstract = {ABSTRACT: Unicellular organisms can engage in a process by which a cell purposefully destroys itself, termed programmed cell death (PCD). While it is clear that the death of specific cells within a multicellular organism could increase inclusive fitness (e.g., during development), the origin of PCD in unicellular organisms is less obvious. Kin selection has been shown to help maintain instances of PCD in existing populations of unicellular organisms; however, competing hypotheses exist about whether additional factors are necessary to explain its origin. Those factors could include an environmental shift that causes latent PCD to be expressed, PCD hitchhiking on a large beneficial mutation, and PCD being simply a common pathology. Here, we present results using an artificial life model to demonstrate that kin selection can, in fact, be sufficient to give rise to PCD in unicellular organisms. Furthermore, when benefits to kin are direct-that is, resources provided to nearby kin-PCD is more beneficial than when benefits are indirect-that is, nonkin are injured, thus increasing the relative amount of resources for kin. Finally, when considering how strict organisms are in determining kin or nonkin (in terms of mutations), direct benefits are viable in a narrower range than indirect benefits.<br><br>OPEN RESEARCH BADGES: This article has been awarded Open Data and Open Materials Badges. All materials and data are publicly accessible via the Open Science Framework at https://github.com/anyaevostinar/SuicidalAltruismDissertation/tree/master/LongTerm.}, }
@article {pmid31454451, year = {2019}, author = {Khodaei, L and Long, TAF}, title = {Kin recognition and co-operative foraging in Drosophila melanogaster larvae.}, journal = {Journal of evolutionary biology}, volume = {32}, number = {12}, pages = {1352-1361}, doi = {10.1111/jeb.13531}, pmid = {31454451}, issn = {1420-9101}, mesh = {Animals ; Behavior, Animal/physiology ; *Cooperative Behavior ; Drosophila melanogaster/*physiology ; Female ; Larva/physiology ; Male ; }, abstract = {A long-standing goal for biologists and social scientists is to understand the factors that lead to the evolution and maintenance of co-operative behaviour between conspecifics. To that end, the fruit fly, Drosophila melanogaster, is becoming an increasingly popular model species to study sociality; however, most of the research to date has focused on adult behaviours. In this study, we set out to examine group-feeding behaviour by larvae and to determine whether the degree of relatedness between individuals mediates the expression co-operation. In a series of assays, we manipulated the average degree of relatedness in groups of third-instar larvae that were faced with resource scarcity, and measured the size, frequency and composition of feeding clusters, as well as the fitness benefits associated with co-operation. Our results suggest that larval D. melanogaster are capable of kin recognition (something that has not been previously described in this species), as clusters were more numerous, larger and involved more larvae, when more closely related kin were present in the social environment. These findings are discussed in the context of the correlated fitness-associated benefits of co-operation, the potential mechanisms by which individuals may recognize kin, and how that kinship may play an important role in facilitating the manifestation of this co-operative behaviour.}, }
@article {pmid31422471, year = {2019}, author = {Cayuela, H and Boualit, L and Laporte, M and Prunier, JG and Preiss, F and Laurent, A and Foletti, F and Clobert, J and Jacob, G}, title = {Kin-dependent dispersal influences relatedness and genetic structuring in a lek system.}, journal = {Oecologia}, volume = {191}, number = {1}, pages = {97-112}, pmid = {31422471}, issn = {1432-1939}, mesh = {Animals ; Birds ; *Breeding ; Female ; France ; Male ; *Microsatellite Repeats ; }, abstract = {Kin selection and dispersal play a critical role in the evolution of cooperative breeding systems. Limited dispersal increases relatedness in spatially structured populations (population viscosity), with the result that neighbours tend to be genealogical relatives. Yet the increase in neighbours' fitness-related performance through altruistic interaction may also result in habitat saturation and thus exacerbate local competition between kin. Our goal was to detect the footprint of kin selection and competition by examining the spatial structure of relatedness and by comparing non-effective and effective dispersal in a population of a lekking bird, Tetrao urogallus. For this purpose, we analysed capture-recapture and genetic data collected over a 6-year period on a spatially structured population of T. urogallus in France. Our findings revealed a strong spatial structure of relatedness in males. They also indicated that the population viscosity could allow male cooperation through two non-exclusive mechanisms. First, at their first lek attendance, males aggregate in a lek composed of relatives. Second, the distance corresponding to non-effective dispersal dramatically outweighed effective dispersal distance, which suggests that dispersers incur high post-settlement costs. These two mechanisms result in strong population genetic structuring in males. In females, our findings revealed a lower level of spatial structure of relatedness and genetic structure in respect to males. Additionally, non-effective dispersal and effective dispersal distances in females were highly similar, which suggests limited post-settlement costs. These results indicate that kin-dependent dispersal decisions and costs have a genetic footprint in wild populations and are factors that may be involved in the evolution of cooperative courtship.}, }
@article {pmid31406338, year = {2019}, author = {Page, AE and Thomas, MG and Smith, D and Dyble, M and Viguier, S and Chaudhary, N and Salali, GD and Thompson, J and Mace, R and Migliano, AB}, title = {Testing adaptive hypotheses of alloparenting in Agta foragers.}, journal = {Nature human behaviour}, volume = {3}, number = {11}, pages = {1154-1163}, pmid = {31406338}, issn = {2397-3374}, support = {MR/P014216/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Adolescent ; Adult ; Aged ; Anthropology, Cultural ; *Caregivers ; Child ; *Child Care ; Child, Preschool ; Cooperative Behavior ; Family ; Female ; Humans ; Infant ; Male ; Middle Aged ; *Parenting ; *Parents ; Philippines ; Social Behavior ; Young Adult ; }, abstract = {Human children are frequently cared for by non-parental caregivers (alloparents), yet few studies have conducted systematic alternative hypothesis tests of why alloparents help. Here we explore whether predictions from kin selection, reciprocity, learning-to-mother and costly signalling hypotheses explain non-parental childcare among Agta hunter-gatherers from the Philippines. To test these hypotheses, we used high-resolution proximity data from 1,701 child-alloparent dyads. Our results indicated that reciprocity and relatedness were positively associated with the number of interactions with a child (our proxy for childcare). Need appeared more influential in close kin, suggesting indirect benefits, while reciprocity proved to be a stronger influence in non-kin, pointing to direct benefits. However, despite shared genes, close and distant kin interactions were also contingent on reciprocity. Compared with other apes, humans are unique in rapidly producing energetically demanding offspring. Our results suggest that the support that mothers require is met through support based on kinship and reciprocity.}, }
@article {pmid31392902, year = {2019}, author = {Schriver, J and Perunovic, WQE and Brymer, K and Hachey, T}, title = {Do Relatives With Greater Reproductive Potential Get Help First?: A Test of the Inclusive Fitness Explanation of Kin Altruism.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {17}, number = {3}, pages = {1474704919867094}, pmid = {31392902}, issn = {1474-7049}, mesh = {Adult ; Aged ; *Altruism ; Emotions/physiology ; Family/*psychology ; Family Relations/*psychology ; Female ; Helping Behavior ; Humans ; Male ; Middle Aged ; Reproduction/*physiology ; Young Adult ; }, abstract = {According to inclusive fitness theory, people are more willing to help those they are genetically related to because relatives share a kin altruism gene and are able to pass it along. We tested this theory by examining the effect of reproductive potential on altruism. Participants read hypothetical scenarios and chose between cousins (Studies 1 and 2) and cousins and friends (Study 3) to help with mundane chores or a life-or-death rescue. In life-or-death situations, participants were more willing to help a cousin preparing to conceive rather than adopt a child (Study 1) and a cousin with high rather than low chance of reproducing (Studies 2 and 3). Patterns in the mundane condition were less consistent. Emotional closeness also contributed to helping intentions (Studies 1 and 2). By experimentally manipulating reproductive potential while controlling for genetic relatedness and emotional closeness, we provide a demonstration of the direct causal effects of reproductive potential on helping intentions, supporting the inclusive fitness explanation of kin altruism.}, }
@article {pmid31381581, year = {2019}, author = {Berkowic, D and Markman, S}, title = {Weighing density and kinship: Aggressive behavior and time allocation in fire salamander (Salamandra infraimmaculata).}, journal = {PloS one}, volume = {14}, number = {8}, pages = {e0220499}, pmid = {31381581}, issn = {1932-6203}, mesh = {Aggression ; Animals ; Behavior, Animal ; Cannibalism ; Female ; Larva/physiology ; Population Density ; Salamandra/*physiology ; }, abstract = {Kin-biased behavior (that is responding differentially to kin and non-kin) is thought to be adaptive in many social interactions. One example of this kin bias is behaving less aggressively toward a relative than a non-relative, a behavior which yields inclusive fitness benefits. However, data are lacking about the ability of animals to weigh their preference for kinship and the density of conspecifics simultaneously and to respond accordingly. Fire salamanders (Salamandra infraimmaculata) larviposit in high densities in ponds. Thus, larvae of different females confront competition and predation by other larvae. We studied whether larvae prefer their kin over particular density or vice versa. We experimentally used a transparent glass aquarium with inner chambers to test the responses of a focal larva toward its siblings and non-siblings. Specifically, we quantified the time a focal larva spent near its siblings or non-siblings, presented in varying densities, and the aggression level it demonstrated. We found that focal larvae spent more time near non-siblings if non-sibling and sibling groups were of equal density. The focal larvae were also more aggressive toward non-siblings. The results may be explained by the cannibalistic nature of these larvae: high density may provide more opportunities for food, especially when non-siblings are present. Further explanations for these findings may include other advantages of staying in a larger group and/or the stronger olfactory and visual stimulation offered by groups compared to a single individual. These findings suggest that larvae make differential responses toward conspecifics depending simultaneously on the level of relatedness and the density of the group. Such responses have important implications for social-aggregation decisions and may especially affect the fitness of cannibalistic species.}, }
@article {pmid31358195, year = {2019}, author = {Spivak, M and Goblirsch, M and Simone-Finstrom, M}, title = {Social-medication in bees: the line between individual and social regulation.}, journal = {Current opinion in insect science}, volume = {33}, number = {}, pages = {49-55}, doi = {10.1016/j.cois.2019.02.009}, pmid = {31358195}, issn = {2214-5753}, mesh = {Animals ; Bees/microbiology/parasitology/*physiology ; Behavior, Animal ; *Feeding Behavior ; Plants/chemistry ; *Social Behavior ; }, abstract = {We use the term social-medication to describe the deliberate consumption or use of plant compounds by social insects that are detrimental to a pathogen or parasite at the colony level, result in increased inclusive fitness to the colony, and have potential costs either at the individual or colony level in the absence of parasite infection. These criteria for social-medication differ from those for self-medication in that inclusive fitness costs and benefits are distinguished from individual costs and benefits. The consumption of pollen and nectar may be considered a form of social immunity if they help fight infection, resulting in a demonstrated increase in colony health and survival. However, the dietary use of pollen and nectar per se is likely not a form of social-medication unless there is a detriment or cost to their consumption in the absence of parasite infection, such as when they contain phytochemicals that are toxic at certain doses. We provide examples among social bees (bumblebees, stingless bees and honey bees) in which the consumption or use of plant compounds have a demonstrated role in parasite defense and health of the colony. We indicate where more work is needed to distinguish between prophylactic and therapeutic effects of these compounds, and whether the effects are observed at the individual or colony level.}, }
@article {pmid31326325, year = {2019}, author = {Birch, J}, title = {Inclusive fitness as a criterion for improvement.}, journal = {Studies in history and philosophy of biological and biomedical sciences}, volume = {76}, number = {}, pages = {101186}, doi = {10.1016/j.shpsc.2019.101186}, pmid = {31326325}, issn = {1879-2499}, mesh = {*Biological Evolution ; Biology/*methods ; *Gene Frequency ; *Genetic Fitness ; Models, Genetic ; Philosophy ; }, abstract = {I distinguish two roles for a fitness concept in the context of explaining cumulative adaptive evolution: fitness as a predictor of gene frequency change, and fitness as a criterion for phenotypic improvement. Critics of inclusive fitness argue, correctly, that it is not an ideal fitness concept for the purpose of predicting gene-frequency change, since it relies on assumptions about the causal structure of social interaction that are unlikely to be exactly true in real populations, and that hold as approximations only given a specific type of weak selection. However, Hamilton took this type of weak selection, on independent grounds, to be responsible for cumulative assembly of complex adaptations. In this special context, I argue that inclusive fitness is distinctively valuable as a criterion for improvement and a standard for optimality. Yet to call inclusive fitness a criterion for improvement and a standard for optimality is not to make any claim about the frequency with which inclusive fitness optimization actually occurs in nature. This is an empirical question that cannot be settled by theory alone. I close with some reflections on the place of inclusive fitness in the long running clash between 'causalist' and 'statisticalist' conceptions of fitness.}, }
@article {pmid31326324, year = {2019}, author = {Huneman, P}, title = {Revisiting darwinian teleology: A case for inclusive fitness as design explanation.}, journal = {Studies in history and philosophy of biological and biomedical sciences}, volume = {76}, number = {}, pages = {101188}, doi = {10.1016/j.shpsc.2019.101188}, pmid = {31326324}, issn = {1879-2499}, mesh = {*Biological Evolution ; Biology/*methods ; *Genetic Fitness ; Models, Genetic ; Philosophy ; }, abstract = {This paper elaborates a general framework to make sense of teleological explanations in Darwinian evolutionary biology. It relies on an attempt to tie natural selection to a sense of optimization. First, after assessing the objections made by any attempt to view selection as a maximising process within population genetics, it understands Grafen's Formal Darwinism (FD) as a conceptual link established between population genetics and behavioral ecology's adaptationist framework (without any empirical commitments). Thus I suggest that this provides a way to make sense of teleological explanations in biology under their various modes. Then the paper criticizes two major ways of accounting for teleology: a Darwinian one, the etiological view of biological functions, and a non-Darwinian one, here labeled "intrinsic teleology" view, which covers several subtypes of accounts, including plasticity-oriented conceptions of evolution or organizational views of function. The former is centered on traits while the latter is centered on organisms; this is shown to imply that both accounts are unable to provide a systematic understanding of biological teleology. Finally the paper argues that viewing teleology as maximization of inclusive fitness along the FD lines as understood here allows one to make sense of both the design of organisms and the individual traits as adaptions. Such notion is thereby claimed to be the proper meaning of teleology in evolutionary biology, since it avoids the opposed pitfalls of etiological views and intrinsic-teleology view, while accounting for the same features as they do.}, }
@article {pmid31325322, year = {2019}, author = {Mullon, C and Lehmann, L}, title = {An evolutionary quantitative genetics model for phenotypic (co)variances under limited dispersal, with an application to socially synergistic traits.}, journal = {Evolution; international journal of organic evolution}, volume = {73}, number = {9}, pages = {1695-1728}, doi = {10.1111/evo.13803}, pmid = {31325322}, issn = {1558-5646}, support = {PP00P3-123344//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/International ; }, mesh = {Animals ; *Biological Evolution ; Breeding ; Genetic Fitness ; Haploidy ; Humans ; *Models, Genetic ; Multivariate Analysis ; Mutation ; *Phenotype ; Probability ; *Selection, Genetic ; *Social Behavior ; }, abstract = {Darwinian evolution consists of the gradual transformation of heritable traits due to natural selection and the input of random variation by mutation. Here, we use a quantitative genetics approach to investigate the coevolution of multiple quantitative traits under selection, mutation, and limited dispersal. We track the dynamics of trait means and of variance-covariances between traits that experience frequency-dependent selection. Assuming a multivariate-normal trait distribution, we recover classical dynamics of quantitative genetics, as well as stability and evolutionary branching conditions of invasion analyses, except that due to limited dispersal, selection depends on indirect fitness effects and relatedness. In particular, correlational selection that associates different traits within-individuals depends on the fitness effects of such associations between-individuals. We find that these kin selection effects can be as relevant as pleiotropy for the evolution of correlation between traits. We illustrate this with an example of the coevolution of two social traits whose association within-individuals is costly but synergistically beneficial between-individuals. As dispersal becomes limited and relatedness increases, associations between-traits between-individuals become increasingly targeted by correlational selection. Consequently, the trait distribution goes from being bimodal with a negative correlation under panmixia to unimodal with a positive correlation under limited dispersal.}, }
@article {pmid31324139, year = {2019}, author = {Garay, J and Garay, BM and Varga, Z and Csiszár, V and Móri, TF}, title = {To save or not to save your family member's life? Evolutionary stability of self-sacrificing life history strategy in monogamous sexual populations.}, journal = {BMC evolutionary biology}, volume = {19}, number = {1}, pages = {147}, pmid = {31324139}, issn = {1471-2148}, mesh = {Animals ; *Biological Evolution ; Genetics, Population ; Genotype ; Humans ; *Life Cycle Stages ; Mutation/genetics ; Phenotype ; *Sexual Behavior ; }, abstract = {BACKGROUND: For the understanding of human nature, the evolutionary roots of human moral behaviour are a key precondition. Our question is as follows: Can the altruistic moral rule "Risk your life to save your family members, if you want them to save your life" be evolutionary stable? There are three research approaches to investigate this problem: kin selection, group selection and population genetics modelling. The present study is strictly based on the last approach.<br><br>RESULTS: We consider monogamous and exogamous families, where at an autosomal locus, dominant-recessive alleles determine the phenotypes in a sexual population. Since all individuals' survival rate is determined by their altruistic family members, we introduce a new population genetics model based on the mating table approach and adapt the verbal definition of evolutionary stability to genotypes. In general, when the resident is recessive, a homozygote is an evolutionarily stable genotype (ESG), if the number of survivors of the resident genotype of the resident homozygote family is greater than that of non-resident heterozygote survivors of the family of the resident homozygote and mutant heterozygote genotypes. Using the introduced genotype dynamics we proved that in the recessive case ESG implies local stability of the altruistic genotype. We apply our general ESG conditions for self-sacrificing life history strategy when the number of new-born offspring does not depend on interactions within the family and the interactions are additive. We find that in this case our ESG conditions give back Hamilton's rule for evolutionary stability of the self-sacrificing life history strategy.<br><br>CONCLUSIONS: In spite of the fact that the kidney transplantations was not a selection factor during the earlier human evolution, nowadays "self-sacrificing" can be observed in the live donor kidney transplantations, when the donor is one of the family members. It seems that selection for self-sacrificing in family produced an innate moral tendency in modulating social cognition in human brain.}, }
@article {pmid31312507, year = {2019}, author = {Woodford, P}, title = {Evaluating inclusive fitness.}, journal = {Royal Society open science}, volume = {6}, number = {6}, pages = {190644}, pmid = {31312507}, issn = {2054-5703}, }
@article {pmid31303163, year = {2019}, author = {Koster, J and Lukas, D and Nolin, D and Power, E and Alvergne, A and Mace, R and Ross, CT and Kramer, K and Greaves, R and Caudell, M and MacFarlan, S and Schniter, E and Quinlan, R and Mattison, S and Reynolds, A and Yi-Sum, C and Massengill, E}, title = {Kinship ties across the lifespan in human communities.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1780}, pages = {20180069}, pmid = {31303163}, issn = {1471-2970}, mesh = {Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Emigrants and Immigrants/psychology ; Female ; Humans ; Infant ; *Longevity ; Male ; Middle Aged ; Reproduction ; Residence Characteristics/statistics &amp; numerical data ; *Social Behavior ; Young Adult ; }, abstract = {A hypothesis for the evolution of long post-reproductive lifespans in the human lineage involves asymmetries in relatedness between young immigrant females and the older females in their new groups. In these circumstances, inter-generational reproductive conflicts between younger and older females are predicted to resolve in favour of the younger females, who realize fewer inclusive fitness benefits from ceding reproduction to others. This conceptual model anticipates that immigrants to a community initially have few kin ties to others in the group, gradually showing greater relatedness to group members as they have descendants who remain with them in the group. We examine this prediction in a cross-cultural sample of communities, which vary in their sex-biased dispersal patterns and other aspects of social organization. Drawing on genealogical and demographic data, the analysis provides general but not comprehensive support for the prediction that average relatedness of immigrants to other group members increases as they age. In rare cases, natal members of the community also exhibit age-related increases in relatedness. We also find large variation in the proportion of female group members who are immigrants, beyond simple traditional considerations of patrilocality or matrilocality, which raises questions about the circumstances under which this hypothesis of female competition are met. We consider possible explanations for these heterogenous results, and we address methodological considerations that merit increased attention for research on kinship and reproductive conflict in human societies. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.}, }
@article {pmid31303162, year = {2019}, author = {Lynch, EC and Lummaa, V and Htut, W and Lahdenperä, M}, title = {Evolutionary significance of maternal kinship in a long-lived mammal.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1780}, pages = {20180067}, pmid = {31303162}, issn = {1471-2970}, mesh = {Animals ; *Biological Evolution ; Elephants/genetics/*physiology ; Family ; Female ; Male ; Reproduction ; Social Behavior ; }, abstract = {Preferential treatment of kin is widespread across social species and is considered a central prerequisite to the evolution of cooperation through kin selection. Though it is well known that, among most social mammals, females will remain within their natal group and often bias social behaviour towards female maternal kin, less is known about the fitness consequences of these relationships. We test the fitness benefits of living with maternal sisters, measured by age-specific female reproduction, using an unusually large database of a semi-captive Asian elephant (Elephas maximus) population. This study system is particularly valuable to an exploration of reproductive trends in a long-lived mammal, because it includes life-history data that span multiple generations, enabling a study of the effects of kinship across a female's lifespan. We find that living near a sister significantly increased the likelihood of annual reproduction among young female elephants, and this effect was strongest when living near a sister 0-5 years younger. Our results show that fitness benefits gained from relationships with kin are age-specific, establish the basis necessary for the formation and maintenance of close social relationships with female kin, and highlight the adaptive importance of matriliny in a long-lived mammal. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.}, }
@article {pmid31303158, year = {2019}, author = {Holekamp, KE and Sawdy, MA}, title = {The evolution of matrilineal social systems in fissiped carnivores.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1780}, pages = {20180065}, pmid = {31303158}, issn = {1471-2970}, mesh = {Animals ; Behavior, Animal ; *Biological Evolution ; Carnivora/genetics/*physiology ; Female ; Hyaenidae/genetics/*physiology ; Lions/genetics/*physiology ; Male ; *Social Behavior ; }, abstract = {We review matrilineal relationships in the societies of fissiped mammalian carnivores, focusing on how the most complex of these may have evolved from simpler systems. Although competition for food is very intense at the trophic level occupied by most carnivores, and although most species of extant fissiped carnivores therefore lead solitary lives, some species show at least rudimentary clustering of maternal kin and matrilineal resource-sharing or transmission of critical resources between generations. The resources shared or transmitted range from individual food items and territories to entire networks of potential allies. The greatest elaboration of matrilineal relationships has occurred in two large carnivores, lions and spotted hyenas, which occur sympatrically throughout much of Africa. The societies of both these species apparently evolved in response to a shared suite of ecological conditions. The highly matrilineal societies of spotted hyenas are unique among carnivores and closely resemble the societies of many cercopithecine primates. The conditions favouring the evolution of matrilineal societies in carnivores include male-biased dispersal, female philopatry, the need for assistance in protecting or provisioning offspring, reliance on large or abundant prey, particularly in open habitat, high population density and kin-structured cooperative interactions that have strong positive effects on fitness. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.}, }
@article {pmid31289691, year = {2019}, author = {Ross, L and Davies, NG and Gardner, A}, title = {How to make a haploid male.}, journal = {Evolution letters}, volume = {3}, number = {2}, pages = {173-184}, pmid = {31289691}, issn = {2056-3744}, abstract = {Haplodiploidy has evolved repeatedly among invertebrates, and appears to be associated with inbreeding. Evolutionary biologists have long debated the possible benefits for females in diplodiploid species to produce haploid sons-beginning their population's transition to haplodiploidy-and whether inbreeding promotes or inhibits this transition. However, little attention has been given to what makes a haploid individual male rather than female, and whether the mechanism of sex determination may modulate the costs and benefits of male haploidy. We remedy this by performing a theoretical analysis of the origin and invasion of male haploidy across the full range of sex-determination mechanisms and sib-mating rates. We find that male haploidy is facilitated by three different mechanisms of sex determination-all involving male heterogamety-and impeded by the others. We also find that inbreeding does not pose an obvious evolutionary barrier, on account of a previously neglected sex-ratio effect whereby the production of haploid sons leads to an abundance of granddaughters that is advantageous in the context of inbreeding. We find empirical support for these predictions in a survey of sex determination and inbreeding across haplodiploids and their sister taxa.}, }
@article {pmid31272291, year = {2020}, author = {Ng, YL}, title = {Active and Passive Facebook Use and Associated Costly Off-line Helping Behavior.}, journal = {Psychological reports}, volume = {123}, number = {6}, pages = {2562-2581}, doi = {10.1177/0033294119860262}, pmid = {31272291}, issn = {1558-691X}, mesh = {Adolescent ; Adult ; Aged ; *Altruism ; Female ; Friends/psychology ; *Helping Behavior ; Humans ; Male ; Middle Aged ; Social Media/*statistics &amp; numerical data ; Young Adult ; }, abstract = {This study examined active and passive Facebook use and the associated costly altruistic behavior. Results supported the hypothesis that social media use, particularly active use, can enhance the perceived relatedness of individuals in need and reduce the influence of genetic relatedness in helping. Passive social media users tended to help kin in both situations involving low and high biological cost, whereas they were less likely to risk themselves to help social media friends and strangers in extraordinary situations involving high biological cost. However, active social media users, who had a broader sense of connectedness with genetically unrelated individuals, were more willing to help social media friends and strangers in both situations involving high and low biological cost.}, }
@article {pmid31271473, year = {2019}, author = {Leeks, A and Dos Santos, M and West, SA}, title = {Transmission, relatedness, and the evolution of cooperative symbionts.}, journal = {Journal of evolutionary biology}, volume = {32}, number = {10}, pages = {1036-1045}, pmid = {31271473}, issn = {1420-9101}, support = {BB/M011224/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {*Biological Evolution ; Computer Simulation ; *Models, Biological ; Symbiosis/*genetics ; }, abstract = {Cooperative interactions between species, termed mutualisms, play a key role in shaping natural ecosystems, economically important agricultural systems, and in influencing human health. Across different mutualisms, there is significant variation in the benefit that hosts receive from their symbionts. Empirical data suggest that transmission mode can help explain this variation: vertical transmission, where symbionts infect their host's offspring, leads to symbionts that provide greater benefits to their hosts than horizontal transmission, where symbionts leave their host and infect other hosts in the population. However, two different theoretical explanations have been given for this pattern: firstly, vertical transmission aligns the fitness interests of hosts and their symbionts; secondly, vertical transmission leads to increased relatedness between symbionts sharing a host, favouring cooperation between symbionts. We used a combination of analytical models and dynamic simulations to tease these factors apart, in order to compare their separate influences and see how they interact. We found that relatedness between symbionts sharing a host, rather than transmission mode per se, was the most important factor driving symbiont cooperation. Transmission mode mattered mainly because it determined relatedness. We also found evolutionary branching throughout much of our simulation, suggesting that a combination of transmission mode and multiplicity of infections could lead to the stable coexistence of different symbiont strategies.}, }
@article {pmid31247419, year = {2019}, author = {Bourke, AF}, title = {Inclusive fitness and the major transitions in evolution.}, journal = {Current opinion in insect science}, volume = {34}, number = {}, pages = {61-67}, doi = {10.1016/j.cois.2019.03.008}, pmid = {31247419}, issn = {2214-5753}, mesh = {Animals ; *Biological Evolution ; *Genetic Fitness ; }, abstract = {Inclusive fitness theory is the leading framework for explaining the major transitions in evolution, whereby free-living subunits (e.g. cells, organisms) have cooperated to form new, higher-level units (e.g. organisms, eusocial societies). The theory has attracted considerable controversy. From a brief survey of the controversy's present status, I conclude that inclusive fitness theory continues to provide both a concept and a principled modelling tool of value for understanding social evolution, including major transitions. Turning to new developments in the study of major transitions, I describe work defining the point of occurrence of major transitions and, from inclusive fitness theory, the required conditions. I also suggest that it remains important to understand the evolution of individuality that occurs beyond such thresholds.}, }
@article {pmid31185857, year = {2019}, author = {Fromhage, L and Jennions, MD}, title = {The strategic reference gene: an organismal theory of inclusive fitness.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1904}, pages = {20190459}, pmid = {31185857}, issn = {1471-2954}, mesh = {*Biological Evolution ; Genetic Fitness ; Models, Genetic ; Phenotype ; Reproduction ; Selection, Genetic/*genetics ; }, abstract = {How to define and use the concept of inclusive fitness is a contentious topic in evolutionary theory. Inclusive fitness can be used to calculate selection on a focal gene, but it is also applied to whole organisms. Individuals are then predicted to appear designed as if to maximize their inclusive fitness, provided that certain conditions are met (formally when interactions between individuals are 'additive'). Here we argue that applying the concept of inclusive fitness to organisms is justified under far broader conditions than previously shown, but only if it is appropriately defined. Specifically, we propose that organisms should maximize the sum of their offspring (including any accrued due to the behaviour/phenotype of relatives), plus any effects on their relatives' offspring production, weighted by relatedness. By contrast, most theoreticians have argued that a focal individual's inclusive fitness should exclude any offspring accrued due to the behaviour of relatives. Our approach is based on the notion that long-term evolution follows the genome's 'majority interest' of building coherent bodies that are efficient 'vehicles' for gene propagation. A gene favoured by selection that reduces the propagation of unlinked genes at other loci (e.g. meiotic segregation distorters that lower sperm production) is eventually neutralized by counter-selection throughout the rest of the genome. Most phenotypes will therefore appear as if designed to maximize the propagation of any given gene in a focal individual and its relatives.}, }
@article {pmid31171982, year = {2019}, author = {Rautiala, P and Helanterä, H and Puurtinen, M}, title = {Extended haplodiploidy hypothesis.}, journal = {Evolution letters}, volume = {3}, number = {3}, pages = {263-270}, pmid = {31171982}, issn = {2056-3744}, abstract = {Evolution of altruistic behavior was a hurdle for the logic of Darwinian evolution. Soon after Hamilton formalized the concept of inclusive fitness, which explains how altruism can evolve, he suggested that the high sororal relatedness brought by haplodiploidy could be why Hymenopterans have a high prevalence in eusocial species, and why helpers in Hymenoptera are always female. Later it was noted that in order to capitalize on the high sororal relatedness, helpers would need to direct help toward sisters, and this would bias the population sex ratio. Under a 1:3 males:females sex ratio, the inclusive fitness valuation a female places on her sister, brother, and an own offspring are equal-apparently removing the benefit of helping over independent reproduction. Based on this argumentation, haplodiploidy hypothesis has been considered a red herring. However, here we show that when population sex ratio, cost of altruism, and population growth rate are considered together, haplodiploidy does promote female helping even with female-biased sex ratio, due the lowered cost of altruism in such populations. Our analysis highlights the need to re-evaluate the role of haplodiploidy in the evolution of helping, and the importance of fully exploring the model assumptions when comparing interactions of population sex ratios and social behaviors.}, }
@article {pmid31164060, year = {2019}, author = {Lenárt, P and Zlámal, F and Kukla, L and Jarkovský, J and Bienertová-Vašků, J}, title = {Sibling relatedness rather than father absence predicts earlier age at menarche in ELSPAC cohort.}, journal = {Biology letters}, volume = {15}, number = {6}, pages = {20190091}, pmid = {31164060}, issn = {1744-957X}, support = {G9815508/MRC_/Medical Research Council/United Kingdom ; MC_PC_19009/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Age Factors ; Child ; *Fathers ; Female ; Humans ; Longitudinal Studies ; Male ; *Menarche ; Pregnancy ; Siblings ; }, abstract = {Many studies during the past 50 years have found an association between father absence and earlier menarche. In connection with these findings, several evolutionary theories assume that father absence is a causal factor accelerating reproductive development. However, a recent study analysing data from the Avon Longitudinal Study of Parents and Children (ALSPAC) found that father absence does not predict age at menarche when adjusted for sibling relatedness. In this study, we have replicated these results in the Czech section of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC), which used the same questionnaires as ALSPAC to study a geographically distinct population. Our results support the conclusion that sibling relatedness rather than father absence predicts age at menarche. Furthermore, our results show that age at menarche in 1990s UK and Czech cohorts is very similar despite socioeconomic differences between the two countries.}, }
@article {pmid31163162, year = {2019}, author = {Ostrowski, EA}, title = {Enforcing Cooperation in the Social Amoebae.}, journal = {Current biology : CB}, volume = {29}, number = {11}, pages = {R474-R484}, doi = {10.1016/j.cub.2019.04.022}, pmid = {31163162}, issn = {1879-0445}, mesh = {*Biological Evolution ; Dictyostelium/*physiology ; *Microbial Interactions ; }, abstract = {Cooperation has been essential to the evolution of biological complexity, but many societies struggle to overcome internal conflicts and divisions. Dictyostelium discoideum, or the social amoeba, has been a useful model system for exploring these conflicts and how they can be resolved. When starved, these cells communicate, gather into groups, and build themselves into a multicellular fruiting body. Some cells altruistically die to form the rigid stalk, while the remainder sit atop the stalk, become spores, and disperse. Evolutionary theory predicts that conflict will arise over which cells die to form the stalk and which cells become spores and survive. The power of the social amoeba lies in the ability to explore how cooperation and conflict work across multiple levels, ranging from proximate mechanisms (how does it work?) to ultimate evolutionary answers (why does it work?). Recent studies point to solutions to the problem of ensuring fairness, such as the ability to suppress selfishness and to recognize and avoid unrelated individuals. This work confirms a central role for kin selection, but also suggests new explanations for how social amoebae might enforce cooperation. New approaches based on genomics are also enabling researchers to decipher for the first time the evolutionary history of cooperation and conflict and to determine its role in shaping the biology of multicellular organisms.}, }
@article {pmid31163155, year = {2019}, author = {Apicella, CL and Silk, JB}, title = {The evolution of human cooperation.}, journal = {Current biology : CB}, volume = {29}, number = {11}, pages = {R447-R450}, doi = {10.1016/j.cub.2019.03.036}, pmid = {31163155}, issn = {1879-0445}, mesh = {*Altruism ; *Biological Evolution ; *Cooperative Behavior ; Humans ; }, abstract = {Darwin viewed cooperation as a perplexing challenge to his theory of natural selection. Natural selection generally favors the evolution of behaviors that enhance the fitness of individuals. Cooperative behavior, which increases the fitness of a recipient at the expense of the donor, contradicts this logic. William D. Hamilton helped to solve the puzzle when he showed that cooperation can evolve if cooperators direct benefits selectively to other cooperators (i.e. assortment). Kinship, group selection and the previous behavior of social partners all provide mechanisms for assortment (Figure 1), and kin selection and reciprocal altruism are the foundation of the kinds of cooperative behavior observed in many animals. Humans also bias cooperation in favor of kin and reciprocating partners, but the scope, scale, and variability of human cooperation greatly exceed that of other animals. Here, we introduce derived features of human cooperation in the context in which they originally evolved, and discuss the processes that may have shaped the evolution of our remarkable capacity for cooperation. We argue that culturally-evolved norms that specify how people should behave provide an evolutionarily novel mechanism for assortment, and play an important role in sustaining derived properties of cooperation in human groups.}, }
@article {pmid31163153, year = {2019}, author = {Kay, T and Lehmann, L and Keller, L}, title = {Kin selection and altruism.}, journal = {Current biology : CB}, volume = {29}, number = {11}, pages = {R438-R442}, doi = {10.1016/j.cub.2019.01.067}, pmid = {31163153}, issn = {1879-0445}, mesh = {*Alleles ; *Altruism ; *Biological Evolution ; *Genetic Fitness ; *Selection, Genetic ; Social Behavior ; }, abstract = {Natural selection is predicated on the 'struggle for existence': life is short, cruel and, whether through predation, disease or starvation, often ends traumatically. It would seem that in such a dog-eat-dog world, organisms ought to act selfishly, and avoid reducing their fitness (expected survival and reproductive success) by expending time and energy helping others. Put another way, alleles that increase the probability of altruism - a behavior whose expression increases the fitness of recipients while decreasing that of the actor - should decrease in frequency across generations and ultimately disappear.}, }
@article {pmid31163152, year = {2019}, author = {Birch, J}, title = {Are kin and group selection rivals or friends?.}, journal = {Current biology : CB}, volume = {29}, number = {11}, pages = {R433-R438}, doi = {10.1016/j.cub.2019.01.065}, pmid = {31163152}, issn = {1879-0445}, mesh = {*Altruism ; Animals ; *Biological Evolution ; *Selection, Genetic ; }, abstract = {Kin selection and group selection were once seen as competing explanatory hypotheses but now tend to be seen as equivalent ways of describing the same basic idea. Yet this 'equivalence thesis' seems not to have brought proponents of kin selection and group selection any closer together. This may be because the equivalence thesis merely shows the equivalence of two statistical formalisms without saying anything about causality. W.D. Hamilton was the first to derive an equivalence result of this type. Yet Hamilton was aware of its limitations, and saw that, while illuminating, it papered over some biologically important distinctions. Attending to these distinctions leads to the concept of 'K-G space', which helps us see where the biological disagreements between proponents of kin selection and group selection really lie.}, }
@article {pmid31141235, year = {2019}, author = {Southon, RJ and Bell, EF and Graystock, P and Wyatt, CDR and Radford, AN and Sumner, S}, title = {High indirect fitness benefits for helpers across the nesting cycle in the tropical paper wasp Polistes canadensis.}, journal = {Molecular ecology}, volume = {28}, number = {13}, pages = {3271-3284}, doi = {10.1111/mec.15137}, pmid = {31141235}, issn = {1365-294X}, mesh = {Animals ; Female ; *Genetic Fitness ; Genetic Markers ; Genotype ; *Helping Behavior ; Male ; Microsatellite Repeats ; *Nesting Behavior ; Panama ; Polymorphism, Single Nucleotide ; Reproduction ; Wasps/genetics/*physiology ; }, abstract = {Explaining the evolution of helping behaviour in the eusocial insects where nonreproductive ("worker") individuals help raise the offspring of other individuals ("queens") remains one of the most perplexing phenomena in the natural world. Polistes paper wasps are popular study models, as workers retain the ability to reproduce: such totipotency is likely representative of the early stages of social evolution. Polistes is thought to have originated in the tropics, where seasonal constraints on reproductive options are weak and social groups are effectively perennial. Yet, most Polistes research has focused on nontropical species, where seasonality causes family groups to disperse; cofoundresses forming new nests the following spring are often unrelated, leading to the suggestion that direct fitness through nest inheritance is key in the evolution of helping behaviour. Here, we present the first comprehensive genetic study of social structure across the perennial nesting cycle of a tropical Polistes-Polistes canadensis. Using both microsatellites and newly developed single nucleotide polymorphism markers, we show that adult cofoundresses are highly related and that brood production is monopolized by a single female across the nesting cycle. Nonreproductive cofoundresses in tropical Polistes therefore have the potential to gain high indirect fitness benefits as helpers from the outset of group formation, and these benefits persist through the nesting cycle. Direct fitness may have been less important in the origin of Polistes sociality than previously suggested. These findings stress the importance of studying a range of species with diverse life history and ecologies when considering the evolution of reproductive strategies.}, }
@article {pmid31132171, year = {2019}, author = {Hitchcock, TJ and Paracchini, S and Gardner, A}, title = {Genomic Imprinting As a Window into Human Language Evolution.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {41}, number = {6}, pages = {e1800212}, doi = {10.1002/bies.201800212}, pmid = {31132171}, issn = {1521-1878}, mesh = {Adaptation, Physiological/genetics ; Altruism ; *Biological Evolution ; Ethics ; Genetic Loci ; Genomic Imprinting/*genetics ; Humans ; Interpersonal Relations ; *Language ; Models, Genetic ; Models, Theoretical ; Phenotype ; }, abstract = {Humans spend large portions of their time and energy talking to one another, yet it remains unclear whether this activity is primarily selfish or altruistic. Here, it is shown how parent-of-origin specific gene expression-or "genomic imprinting"-may provide an answer to this question. First, it is shown why, regarding language, only altruistic or selfish scenarios are expected. Second, it is pointed out that an individual's maternal-origin and paternal-origin genes may have different evolutionary interests regarding investment into language, and that this intragenomic conflict may drive genomic imprinting which-as the direction of imprint depends upon whether investment into language is relatively selfish or altruistic-may be used to discriminate between these two possibilities. Third, predictions concerning the impact of various mutations and epimutations at imprinted loci on language pathologies are derived. In doing so, a framework is developed that highlights avenues for using intragenomic conflicts to investigate the evolutionary drivers of language.}, }
@article {pmid31130904, year = {2019}, author = {Shakhar, K}, title = {The Inclusive Behavioral Immune System.}, journal = {Frontiers in psychology}, volume = {10}, number = {}, pages = {1004}, pmid = {31130904}, issn = {1664-1078}, abstract = {Although living in social groups offers many advantages, it comes at a cost of increased transmissible disease. The behavioral immune system (BIS) is thought to have evolved as a first line of defense against such infections. It acts by minimizing the contact of yet uninfected hosts with potential pathogens. The BIS has been observed in a wide range of animals including insects, amphibians and mammals, but most research has focused on humans where the BIS is guided by complex cognitive and emotional processing. When researchers discuss the evolutionary origin of the BIS, they assess how it raises individual fitness. What would happen though if we shift our attention to the evolutionary unit of selection - the gene? Success would be measured as the change in the gene's prevalence in the entire population, and additional behaviors would come to our attention - those that benefit relatives, i.e., behaviors that raise inclusive fitness. One widely-recognized example of the inclusive BIS is social immunity, which is prevalent among eusocial organisms such as bees and ants. Their colonies engage in a collaborative protective behavior such as grooming and the removal of infected members from the nest. Another example may be sickness behavior, which includes the behavioral, cognitive and emotional symptoms that accompany infection, such as fatigue, and loss of appetite and social interest. My colleague and I recently suggested that sickness behavior has evolved because it reduces the direct and indirect contact between an infected host and its healthy kin - improving inclusive fitness. These additional behaviors are not carried out by the healthy individuals, but rather by whole communities in the first case, and by already infected individuals in the second. Since they step beyond the classical definition of BIS, it may be useful to broaden the term to the inclusive behavioral immune system.}, }
@article {pmid31094597, year = {2019}, author = {Duncan, C and Gaynor, D and Clutton-Brock, T and Dyble, M}, title = {The Evolution of Indiscriminate Altruism in a Cooperatively Breeding Mammal.}, journal = {The American naturalist}, volume = {193}, number = {6}, pages = {841-851}, doi = {10.1086/703113}, pmid = {31094597}, issn = {1537-5323}, mesh = {*Altruism ; Animals ; *Biological Evolution ; Carnivora/*genetics/psychology ; *Cooperative Behavior ; Female ; Male ; *Models, Genetic ; }, abstract = {Kin selection theory suggests that altruistic behaviors can increase the fitness of altruists when recipients are genetic relatives. Although selection can favor the ability of organisms to preferentially cooperate with close kin, indiscriminately helping all group mates may yield comparable fitness returns if relatedness within groups is very high. Here, we show that meerkats (Suricata suricatta) are largely indiscriminate altruists who do not alter the amount of help provided to pups or group mates in response to their relatedness to them. We present a model showing that indiscriminate altruism may yield greater fitness payoffs than kin discrimination where most group members are close relatives and errors occur in the estimation of relatedness. The presence of errors in the estimation of relatedness provides a feasible explanation for associations between kin discriminative helping and group relatedness in eusocial and cooperatively breeding animals.}, }
@article {pmid31094019, year = {2019}, author = {Jänig, S and Weiß, BM and Birkemeyer, C and Widdig, A}, title = {Comparative chemical analysis of body odor in great apes.}, journal = {American journal of primatology}, volume = {81}, number = {6}, pages = {e22976}, doi = {10.1002/ajp.22976}, pmid = {31094019}, issn = {1098-2345}, support = {WI 1808/3-1//Deutsche Forschungsgemeinschaft/International ; R00061//Universit&#xe4;t Leipzig/International ; }, mesh = {Age Factors ; Animals ; Female ; Gas Chromatography-Mass Spectrometry ; Gorilla gorilla/*physiology ; Male ; Odorants/*analysis ; Pan paniscus/*physiology ; Pan troglodytes/*physiology ; Pongo abelii/*physiology ; Sex Factors ; }, abstract = {Olfaction is important across the animal kingdom for transferring information on, for example, species, sex, group membership, or reproductive parameters. Its relevance has been established in primates including humans, yet research on great apes still is fragmentary. Observational evidence indicates that great apes use their sense of smell in various contexts, but the information content of their body odor has not been analyzed. Our aim was therefore to compare the chemical composition of body odor in great ape species, namely Sumatran orangutans (Pongo abelii (Lesson, 1827), one adult male, five adult females, four nonadults), Western lowland gorillas (Gorilla gorilla gorilla (Savage, 1847), one adult male, two adult females, one nonadult), common chimpanzees (Pan troglodytes (Blumenbach, 1775), four adult males, nine adult females, four nonadults), and bonobos (Pan paniscus (Schwarz, 1929), two adult males, four adult females, two nonadults). We collected 195 samples (five per individual) of 39 captive individuals using cotton swabs and analyzed them using gas chromatography mass spectrometry. We compared the sample richness and intensity, similarity of chemical composition, and relative abundance of compounds. Results show that species, age, and potentially sex have an impact on the variance between odor profiles. Richness and intensity varied significantly between species (gorillas having the highest, bonobos the lowest richness and intensity), and with age (both increasing with age). Richness and intensity did not vary between sexes. Odor samples of the same species were more similar to each other than samples of different species. Among all compounds identified some were associated with age (N = 7), sex (N = 6), and species-related (N = 37) variance. Our study contributes to the basic understanding of olfactory communication in hominids by showing that the chemical composition of body odor varies across species and individuals, containing potentially important information for social communication.}, }
@article {pmid31023888, year = {2019}, author = {Geist, KS and Strassmann, JE and Queller, DC}, title = {Family quarrels in seeds and rapid adaptive evolution in Arabidopsis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {19}, pages = {9463-9468}, pmid = {31023888}, issn = {1091-6490}, mesh = {*Adaptation, Physiological ; Arabidopsis/*physiology ; *Biological Evolution ; Endosperm/*physiology ; }, abstract = {Evolutionary conflict can drive rapid adaptive evolution, sometimes called an arms race, because each party needs to respond continually to the adaptations of the other. Evidence for such arms races can sometimes be seen in morphology, in behavior, or in the genes underlying sexual interactions of host-pathogen interactions, but is rarely predicted a priori. Kin selection theory predicts that conflicts of interest should usually be reduced but not eliminated among genetic relatives, but there is little evidence as to whether conflict within families can drive rapid adaptation. Here we test multiple predictions about how conflict over the amount of resources an offspring receives from its parent would drive rapid molecular evolution in seed tissues of the flowering plant Arabidopsis As predicted, there is more adaptive evolution in genes expressed in Arabidopsis seeds than in other specialized organs, more in endosperms and maternal tissues than in embryos, and more in the specific subtissues involved in nutrient transfer. In the absence of credible alternative hypotheses, these results suggest that kin selection and conflict are important in plants, that the conflict includes not just the mother and offspring but also the triploid endosperm, and that, despite the conflict-reducing role of kinship, family members can engage in slow but steady tortoise-like arms races.}, }
@article {pmid31002764, year = {2019}, author = {Sbarra, DA and Briskin, JL and Slatcher, RB}, title = {Smartphones and Close Relationships: The Case for an Evolutionary Mismatch.}, journal = {Perspectives on psychological science : a journal of the Association for Psychological Science}, volume = {14}, number = {4}, pages = {596-618}, doi = {10.1177/1745691619826535}, pmid = {31002764}, issn = {1745-6924}, mesh = {Biological Evolution ; Humans ; *Interpersonal Relations ; *Object Attachment ; *Smartphone ; *Social Behavior ; Trust ; }, abstract = {This article introduces and outlines the case for an evolutionary mismatch between smartphones and the social behaviors that help form and maintain close social relationships. As psychological adaptations that enhance human survival and inclusive fitness, self-disclosure and responsiveness evolved in the context of small kin networks to facilitate social bonds, promote trust, and enhance cooperation. These adaptations are central to the development of attachment bonds, and attachment theory is a middle-level evolutionary theory that provides a robust account of the ways human bonding provides for reproductive and inclusive fitness. Evolutionary mismatches operate when modern contexts cue ancestral adaptations in a manner that does not provide for their adaptive benefits. We argue that smartphones and their affordances, although highly beneficial in many circumstances, cue humans' evolved needs for self-disclosure and responsiveness across broad virtual networks and, in turn, have the potential to undermine immediate interpersonal interactions. We review emerging evidence on the topic of technoference, which is defined as the ways in which smartphone use may interfere with or intrude into everyday social interactions. The article concludes with an empirical agenda for advancing the integrative study of smartphones, intimacy processes, and close relationships.}, }
@article {pmid30993671, year = {2019}, author = {Levin, SR and Grafen, A}, title = {Inclusive fitness is an indispensable approximation for understanding organismal design.}, journal = {Evolution; international journal of organic evolution}, volume = {73}, number = {6}, pages = {1066-1076}, pmid = {30993671}, issn = {1558-5646}, support = {//Natural Environment Research Council/International ; //Clarendon Fund/International ; //Hertford College, University of Oxford/International ; }, mesh = {Gene Frequency ; *Genetic Fitness ; *Models, Biological ; Models, Genetic ; *Selection, Genetic ; }, abstract = {For some decades most biologists interested in design have agreed that natural selection leads to organisms acting as if they are maximizing a quantity known as "inclusive fitness." This maximization principle has been criticized on the (uncontested) grounds that other quantities, such as offspring number, predict gene frequency changes accurately in a wider range of mathematical models. Here, we adopt a resolution offered by Birch, who accepts the technical difficulties of establishing inclusive fitness maximization in a fully general model, while concluding that inclusive fitness is still useful as an organizing framework. We set out in more detail why inclusive fitness is such a practical and powerful framework, and provide verbal and conceptual arguments for why social biology would be more or less impossible without it. We aim to help mathematicians understand why social biologists are content to use inclusive fitness despite its theoretical weaknesses. Here, we also offer biologists practical advice for avoiding potential pitfalls.}, }
@article {pmid30967090, year = {2019}, author = {Cotter, SC and Pincheira-Donoso, D and Thorogood, R}, title = {Defences against brood parasites from a social immunity perspective.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1769}, pages = {20180207}, pmid = {30967090}, issn = {1471-2970}, mesh = {Animals ; Biological Evolution ; *Birds/parasitology/physiology ; *Cues ; *Host-Parasite Interactions ; *Insecta/parasitology/physiology ; *Recognition, Psychology ; *Social Behavior ; }, abstract = {Parasitic interactions are so ubiquitous that all multicellular organisms have evolved a system of defences to reduce their costs, whether the parasites they encounter are the classic parasites which feed on the individual, or brood parasites which usurp parental care. Many parallels have been drawn between defences deployed against both types of parasite, but typically, while defences against classic parasites have been selected to protect survival, those against brood parasites have been selected to protect the parent's inclusive fitness, suggesting that the selection pressures they impose are fundamentally different. However, there is another class of defences against classic parasites that have specifically been selected to protect an individual's inclusive fitness, known as social immunity. Social immune responses include the anti-parasite defences typically provided for others in kin-structured groups, such as the antifungal secretions produced by termite workers to protect the brood. Defences against brood parasites, therefore, are more closely aligned with social immune responses. Much like social immunity, host defences against brood parasitism are employed by a donor (a parent) for the benefit of one or more recipients (typically kin), and as with social defences against classic parasites, defences have therefore evolved to protect the donor's inclusive fitness, not the survival or ultimately the fitness of individual recipients This can lead to severe conflicts between the different parties, whose interests are not always aligned. Here, we consider defences against brood parasitism in the light of social immunity, at different stages of parasite encounter, addressing where conflicts occur and how they might be resolved. We finish with considering how this approach could help us to address longstanding questions in our understanding of brood parasitism. This article is part of the theme issue 'The coevolutionary biology of brood parasitism: from mechanism to pattern'.}, }
@article {pmid30967088, year = {2019}, author = {Gloag, R and Beekman, M}, title = {The brood parasite's guide to inclusive fitness theory.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1769}, pages = {20180198}, pmid = {30967088}, issn = {1471-2970}, mesh = {Animals ; Birds/genetics/parasitology/*physiology ; Female ; *Genetic Fitness ; *Host-Parasite Interactions ; Insecta/genetics/parasitology/*physiology ; *Nesting Behavior ; Reproduction ; Social Behavior ; }, abstract = {Hamilton's theory of inclusive fitness provides a framework for understanding the evolution of social behaviour between kin, including parental and alloparental care. Brood parasitism is a reproductive tactic in which parasites exploit the care of other individuals of the same species (conspecific parasitism) or different species (interspecific parasitism) to rear their brood. Here, drawing from examples in birds and social insects, we identify two insights into brood parasitism that stem from inclusive fitness theory. First, the kin structure within nests, or between neighbouring nests, can create a niche space favouring the evolution of conspecific parasitism. For example, low average relatedness within social insect nests can increase selection for reproductive cheats. Likewise, high average relatedness between adjacent nests of some birds can increase a female's tolerance of parasitism by her neighbour. Second, intrabrood conflict will be high in parasitized broods, from the perspective of both parasite and host young, relative to unparasitized broods. We also discuss offspring recognition by hosts as an example of discrimination in a kin-selected social behaviour. We conclude that the inclusive fitness framework is instructive for understanding aspects of brood parasite and host evolution. In turn, brood parasites present some unique opportunities to test the predictions of inclusive fitness theory. This article is part of the theme issue 'The coevolutionary biology of brood parasitism: from mechanism to pattern'.}, }
@article {pmid30966878, year = {2019}, author = {Vitikainen, EIK and Thompson, FJ and Marshall, HH and Cant, MA}, title = {Live long and prosper: durable benefits of early-life care in banded mongooses.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1770}, pages = {20180114}, pmid = {30966878}, issn = {1471-2970}, mesh = {Animals ; Cooperative Behavior ; Female ; *Helping Behavior ; Herpestidae/growth &amp; development/*physiology ; *Longevity ; Male ; *Reproduction ; }, abstract = {Kin selection theory defines the conditions for which altruism or 'helping' can be favoured by natural selection. Tests of this theory in cooperatively breeding animals have focused on the short-term benefits to the recipients of help, such as improved growth or survival to adulthood. However, research on early-life effects suggests that there may be more durable, lifelong fitness impacts to the recipients of help, which in theory should strengthen selection for helping. Here, we show in cooperatively breeding banded mongooses (Mungos mungo) that care received in the first 3 months of life has lifelong fitness benefits for both male and female recipients. In this species, adult helpers called 'escorts' form exclusive one-to-one caring relationships with specific pups (not their own offspring), allowing us to isolate the effects of being escorted on later reproduction and survival. Pups that were more closely escorted were heavier at sexual maturity, which was associated with higher lifetime reproductive success for both sexes. Moreover, for female offspring, lifetime reproductive success increased with the level of escorting received per se, over and above any effect on body mass. Our results suggest that early-life social care has durable benefits to offspring of both sexes in this species. Given the well-established developmental effects of early-life care in laboratory animals and humans, we suggest that similar effects are likely to be widespread in social animals more generally. We discuss some of the implications of durable fitness benefits for the evolution of intergenerational helping in cooperative animal societies, including humans. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.}, }
@article {pmid30966877, year = {2019}, author = {Kuijper, B and Johnstone, RA}, title = {The evolution of early-life effects on social behaviour-why should social adversity carry over to the future?.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1770}, pages = {20180111}, pmid = {30966877}, issn = {1471-2970}, mesh = {Adaptation, Physiological ; Animals ; *Biological Evolution ; *Helping Behavior ; Humans ; Invertebrates/physiology ; *Selection, Genetic ; *Social Behavior ; Vertebrates/physiology ; }, abstract = {Numerous studies have shown that social adversity in early life can have long-lasting consequences for social behaviour in adulthood, consequences that may in turn be propagated to future generations. Given these intergenerational effects, it is puzzling why natural selection might favour such sensitivity to an individual's early social environment. To address this question, we model the evolution of social sensitivity in the development of helping behaviours, showing that natural selection indeed favours individuals whose tendency to help others is dependent on early-life social experience. In organisms with non-overlapping generations, we find that natural selection can favour positive social feedbacks, in which individuals who received more help in early life are also more likely to help others in adulthood, while individuals who received no early-life help develop low tendencies to help others later in life. This positive social sensitivity is favoured because of an intergenerational relatedness feedback: patches with many helpers tend to be more productive, leading to higher relatedness within the local group, which in turn favours higher levels of help in the next generation. In organisms with overlapping generations, this positive feedback is less likely to occur, and those who received more help may instead be less likely to help others (negative social feedback). We conclude that early-life social influences can lead to strong between-individual differences in helping behaviour, which can take different forms dependent on the life history in question. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.}, }
@article {pmid30963887, year = {2018}, author = {Schindler, S and Radford, AN}, title = {Factors influencing within-group conflict over defence against conspecific outsiders seeking breeding positions.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1893}, pages = {20181669}, pmid = {30963887}, issn = {1471-2954}, mesh = {Animals ; Birds/*physiology ; *Conflict, Psychological ; Female ; Fishes/*physiology ; Male ; Mammals/*physiology ; Models, Biological ; *Reproduction ; }, abstract = {In social species, groups face a variety of threats from conspecific outsiders. Defensive actions are therefore common, but there is considerable variation in which individuals contribute and to what extent. There has been some theoretical exploration of this variation when the defence is of shared resources, but the relative contributions when a single intruder threatens a particular breeding position have received less attention. Defensive actions are costly, both for the individual and dependent young, and contributions are likely to differ depending on individual sex, rank and size, current breeding stage, infanticide risk and relatedness levels. Here, we model analytically the relative fitness benefits of different group members to engaging in defence against individual intruders and determine when within-group conflicts of interest might arise over these defensive contributions. Conflicts of interest between the challenged breeder and other group members depend on relatedness to the brood and the potential relatedness reduction if an intruder acquires breeding status. Conflicts are more likely to occur when there is a low chance of winning the contest, low infanticide rates, inefficient defence from helpers, a long remaining brood-dependency period and high external (non-contest-related) mortality. Our work can help explain variation in defensive actions against out-group threats.}, }
@article {pmid30963856, year = {2019}, author = {Faria, GS and Varela, SAM and Gardner, A}, title = {The social evolution of sleep: sex differences, intragenomic conflicts and clinical pathologies.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1894}, pages = {20182188}, pmid = {30963856}, issn = {1471-2954}, mesh = {*Altruism ; Animals ; *Biological Evolution ; Female ; Humans ; Male ; Models, Genetic ; Sex Characteristics ; Sleep/*physiology ; *Social Behavior ; }, abstract = {Sleep appears to be essential for most animals, including humans. Accordingly, individuals who sacrifice sleep are expected to incur costs and so should only be evolutionarily favoured to do this when these costs are offset by other benefits. For instance, a social group might benefit from having some level of wakefulness during the sleeping period if this guards against possible threats. Alternatively, individuals might sacrifice sleep in order to gain an advantage over mate competitors. Here, we perform a theoretical analysis of the social evolutionary pressures that drive investment into sleep versus wakefulness. Specifically, we: investigate how relatedness between social partners may modulate sleeping strategies, depending upon whether sleep sacrifice is selfish or altruistic; determine the conditions under which the sexes are favoured to adopt different sleeping strategies; identify the potential for intragenomic conflict between maternal-origin versus paternal-origin genes regarding an individual's sleeping behaviour; translate this conflict into novel and readily testable predictions concerning patterns of gene expression; and explore the concomitant effects of different kinds of mutations, epimutations, and uniparental disomies in relation to sleep disorders and other clinical pathologies. Our aim is to provide a theoretical framework for future empirical data and stimulate further research on this neglected topic.}, }
@article {pmid30958139, year = {2019}, author = {Humphreys, RK and Ruxton, GD}, title = {Adaptive suicide: is a kin-selected driver of fatal behaviours likely?.}, journal = {Biology letters}, volume = {15}, number = {2}, pages = {20180823}, pmid = {30958139}, issn = {1744-957X}, mesh = {Animals ; Biological Evolution ; Host-Parasite Interactions ; Insecta ; *Parasites ; *Suicide ; Symbiosis ; }, abstract = {While several manipulated host behaviours are accepted as extended phenotypes of parasites, there remains debate over whether other altered behaviours in hosts following parasitic invasion represent cases of parasite manipulation, host defence or the pathology of infection. One particularly controversial subject is 'suicidal behaviour' in infected hosts. The host-suicide hypothesis proposes that host death benefits hosts doomed to reduced direct fitness by protecting kin from parasitism and therefore increasing inclusive fitness. However, adaptive suicide has been difficult to demonstrate conclusively as a host adaptation in studies on social or clonal insects, for whom high relatedness should enable greater inclusive fitness benefits. Following discussion of empirical and theoretical works from a behavioural ecology perspective, this review finds that the most persuasive evidence for selection of adaptive suicide comes from bacteria. Despite a focus on parasites, driven by the existing literature, the potential for the evolution of adaptive suicidal behaviour in hosts is also considered to apply to cases of infection by pathogens, provided that the disease has a severe effect on direct fitness and that suicidal behaviour can affect pathogen transmission dynamics. Suggestions are made for future research and a broadening of the possible implications for coevolution between parasites and hosts.}, }
@article {pmid30949227, year = {2019}, author = {Spring, S and Lehner, M and Huber, L and Ringler, E}, title = {Oviposition and father presence reduce clutch cannibalism by female poison frogs.}, journal = {Frontiers in zoology}, volume = {16}, number = {}, pages = {8}, pmid = {30949227}, issn = {1742-9994}, support = {P 24788/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {BACKGROUND: The consumption of conspecific young by adult individuals is a common phenomenon across various animal taxa. Possible adaptive benefits of such behaviour include the acquisition of nutrients, decreased competition for one's own offspring, and/or increased mating opportunities. Clutch cannibalism has occasionally been observed in several species of Neotropical poison frogs, but the circumstances under which this behaviour occurs has rarely been investigated experimentally. Recent experiments with the poison frog Allobates femoralis have shown that males indiscriminately transport all clutches located inside their own territory to bodies of water, but become highly cannibalistic when taking over a new territory. Females are able to indirectly discriminate between their own and foreign clutches by location and take over transport duties of their own clutches only in the absence of the father. Cannibalism by A. femoralis females has not been previously observed. We thus asked if, and under which circumstances, cannibalism of unrelated clutches by female A. femoralis would occur, by manipulating the presence of the clutch's father, the female's own reproductive state, and the female's familiarity with the environment.<br><br>RESULTS: Females clearly cannibalize foreign clutches. Cannibalism was most pronounced when the female had not recently produced her own clutch and the father of the foreign clutch was absent. The female's familiarity with the area had no significant influence on the likelihood of cannibalism to occur.<br><br>CONCLUSIONS: Our data indicate that both previous oviposition and the father's presence reduce cannibalistic behaviour in A. femoralis females. Cannibalistic females may gain nutritional benefits or enhanced inclusive fitness by preying on other females' offspring. The finding that the father's presence at the clutch site/territory was sufficient to reduce cannibalism by females suggests a prominent role of male territoriality for the evolution of male parental care.}, }
@article {pmid30940017, year = {2019}, author = {Smith, AR and Kapheim, KM and Kingwell, CJ and Wcislo, WT}, title = {A split sex ratio in solitary and social nests of a facultatively social bee.}, journal = {Biology letters}, volume = {15}, number = {4}, pages = {20180740}, pmid = {30940017}, issn = {1744-957X}, mesh = {Altruism ; Animals ; Bees ; Biological Evolution ; Female ; Male ; Reproduction ; *Sex Ratio ; *Social Behavior ; }, abstract = {A classic prediction of kin selection theory is that a mixed population of social and solitary nests of haplodiploid insects should exhibit a split sex ratio among offspring: female biased in social nests, male biased in solitary nests. Here, we provide the first evidence of a solitary-social split sex ratio, using the sweat bee Megalopta genalis (Halictidae). Data from 2502 offspring collected from naturally occurring nests across 6 years spanning the range of the M. genalis reproductive season show that despite significant yearly and seasonal variation, the offspring sex ratio of social nests is consistently more female biased than in solitary nests. This suggests that split sex ratios may facilitate the evolutionary origins of cooperation based on reproductive altruism via kin selection.}, }
@article {pmid30795688, year = {2019}, author = {Atchison, BJ and Goodwin, DL}, title = {"My Child May Be Ready, but I Am Not": Parents' Experiences of Their Children's Transition to Inclusive Fitness Settings.}, journal = {Adapted physical activity quarterly : APAQ}, volume = {36}, number = {2}, pages = {282-301}, doi = {10.1123/apaq.2018-0101}, pmid = {30795688}, issn = {1543-2777}, mesh = {Adolescent ; Adult ; Child ; Disabled Persons ; *Exercise ; Fear ; Female ; Financing, Government ; Fitness Centers ; Government Programs ; Humans ; Internal-External Control ; Interviews as Topic ; Male ; Middle Aged ; Parents/*psychology ; Qualitative Research ; Young Adult ; }, abstract = {Parents play an essential role in the transition from separate physical activity programs to inclusive settings for their children. The purpose of this study was to explore experiences of parents as they anticipate and prepare for their children experiencing disability to transition, understand strategies used to address transition, and gain insights into the supports important to families during transition. Using an interpretative phenomenological analysis research approach, semistructured one-on-one interviews were conducted with 8 parents whose children were undergoing the transition from separate to inclusive community fitness contexts. Four themes described the experiences of parents as they anticipated, prepared for, and supported their child to transition: My child may be ready, but I am not; fear of outside judgment; playing by their rules; and reframing our thinking. Using Schlossberg's model, the tensions parents faced as they negotiated new roles, relationships, routines, and assumptions as they moved through the transition process were uncovered. The parents experienced transition alongside their children, providing insights for fitness and health-promotion professionals. Without preparation for transition, apprehensions and hesitancy may postpone or prevent their children's transition to community programs.}, }
@article {pmid30787361, year = {2019}, author = {David-Barrett, T}, title = {Network Effects of Demographic Transition.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {2361}, pmid = {30787361}, issn = {2045-2322}, abstract = {Traditional human societies use two of biology's solutions to reduce free-riding: by collaborating with relatives, they rely on the mechanism of kin-selection, and by forming highly clustered social kin-networks, they can efficiently use reputation dynamics. Both of these solutions assume the presence of relatives. This paper shows how social networks change during demographic transition. With falling fertility, there are fewer children that could be relatives to one another. As the missing kin are replaced by non-kin friends, local clustering in the social network drops. This effect is compounded by increasing population size, characteristic of demographic transition. The paper also shows that the speed at which reputation spreads in the network slows down due to both falling fertility and increasing group size. Thus, demographic transition weakens both mechanisms for eliminating free-riders: there are fewer relatives around, and reputation spreads slower. This new link between falling fertility and the altered structure of the social network offers novel interpretations of the origins of legal institutions, the Small World phenomenon, the social impact of urbanisation, and the birds-of-a-feather friendship choice heuristic.}, }
@article {pmid30744976, year = {2019}, author = {Engelhardt, SC and Bergeron, P and Gagnon, A and Dillon, L and Pelletier, F}, title = {Using Geographic Distance as a Potential Proxy for Help in the Assessment of the Grandmother Hypothesis.}, journal = {Current biology : CB}, volume = {29}, number = {4}, pages = {651-656.e3}, doi = {10.1016/j.cub.2019.01.027}, pmid = {30744976}, issn = {1879-0445}, mesh = {Aged ; Aged, 80 and over ; Family Characteristics/*history ; Female ; France/ethnology ; Genetic Fitness/*physiology ; Geography ; *Grandparents ; History, 17th Century ; History, 18th Century ; Humans ; *Longevity ; Middle Aged ; Mortality/*history ; Quebec ; }, abstract = {Life-history theory predicts that selection could favor the decoupling of somatic and reproductive senescence if post-reproductive lifespan (PRLS) provides additional indirect fitness benefits [1, 2]. The grandmother hypothesis proposes that prolonged PRLS evolved because post-reproductive grandmothers gain inclusive fitness benefits by helping their daughters and grandchildren [3, 4]. Because most historical human data do not report direct evidence of help, we hypothesized that geographic distance between individuals may be inversely related to their capacity to help. Using an exceptionally detailed dataset of pre-industrial French settlers in the St. Lawrence Valley during the 17[th] and 18[th] centuries, we assessed the potential for grandmothers to improve their inclusive fitness by helping their descendants, and we evaluated how this effect varied with geographic distance, ranging between 0 and 325 km, while accounting for potential familial genetic and environmental effects [5-9]. Grandmothers (F0) who were alive allowed their daughters (F1) to increase their number of offspring (F2) born by 2.1 and to increase their number of offspring surviving to 15 years of age by 1.1 compared to when grandmothers were dead. However, the age at first reproduction was not influenced by the life status (alive or dead) of grandmothers. As geographic distance increased, the number of offspring born and lifetime reproductive success decreased, while the age at first reproduction increased, despite the grandmother being alive in these analyses. Our study suggests that geographic proximity has the potential to modulate inclusive fitness, supporting the grandmother hypothesis, and to contribute to our understanding of the evolution of PRLS.}, }
@article {pmid30744967, year = {2019}, author = {Chapman, SN and Pettay, JE and Lummaa, V and Lahdenperä, M}, title = {Limits to Fitness Benefits of Prolonged Post-reproductive Lifespan in Women.}, journal = {Current biology : CB}, volume = {29}, number = {4}, pages = {645-650.e3}, doi = {10.1016/j.cub.2018.12.052}, pmid = {30744967}, issn = {1879-0445}, mesh = {Aged ; Aged, 80 and over ; Family Characteristics ; Female ; Finland ; Genetic Fitness/*physiology ; *Grandparents ; Humans ; *Longevity ; Middle Aged ; Postmenopause/*physiology ; }, abstract = {Recent advances in medicine and life-expectancy gains have fueled multidisciplinary research into the limits of human lifespan [1-3]. Ultimately, how long humans can live for may depend on selection favoring extended longevity in our evolutionary past [4]. Human females have an unusually extended post-reproductive lifespan, which has been explained by the fitness benefits provided from helping to raise grandchildren following menopause [5, 6]. However, formal tests of whether such grandmothering benefits wane with grandmother age and explain the observed length of post-reproductive lifespan are missing. This is critical for understanding prevailing selection pressures on longevity but to date has been overlooked as a possible mechanism driving the evolution of lifespan. Here, we use extensive data from pre-industrial humans to show that fitness gains from grandmothering are dependent on grandmother age, affecting selection on the length of post-reproductive lifespan. We find both opportunities and ability to help grandchildren declined with age, while the hazard of death of women increased greatly in their late 60s and 70s compared to menopausal ages, together implying waning selection on subsequent longevity. The presence of maternal grandmothers aged 50-75 increased grandchild survival after weaning, confirming the fitness advantage of post-reproductive lifespan. However, co-residence with paternal grandmothers aged 75+ was detrimental to grandchild survival, with those grandmothers close to death and presumably in poorer health particularly associated with lower grandchild survival. The age limitations of gaining inclusive fitness from grandmothering suggests that grandmothering can select for post-reproductive longevity only up to a certain point.}, }
@article {pmid30720369, year = {2019}, author = {Almond, EJ and Huggins, TJ and Crowther, LP and Parker, JD and Bourke, AFG}, title = {Queen Longevity and Fecundity Affect Conflict with Workers over Resource Inheritance in a Social Insect.}, journal = {The American naturalist}, volume = {193}, number = {2}, pages = {256-266}, doi = {10.1086/701299}, pmid = {30720369}, issn = {1537-5323}, mesh = {*Aggression ; Animals ; Bees/*physiology ; Female ; *Fertility ; *Longevity ; Male ; *Models, Biological ; Reproduction ; }, abstract = {Resource inheritance is a major source of conflict in animal societies. However, the assumptions and predictions of models of conflict over resource inheritance have not been systematically tested within a single system. We developed an inclusive fitness model for annual eusocial Hymenoptera that predicts a zone of conflict in which future reproductive workers are selected to enforce nest inheritance before the queen is selected to cede the nest. We experimentally tested key elements of this model in the bumblebee Bombus terrestris. In colonies from which queens were sequentially removed, queen tenure was significantly negatively associated with worker male production, confirming that workers gain direct fitness by usurping the queen. In unmanipulated colonies, queen fecundity decreased significantly over the latter part of the colony cycle, confirming that workers' indirect fitness from maintaining queens declines over time. Finally, in an experiment simulating loss of queen fecundity by removal of queens' eggs, worker-to-queen aggression increased significantly and aggressive workers were significantly more likely to become egg layers, consistent with workers monitoring queen fecundity to assess the net benefit of future reproduction. Overall, by upholding key assumptions and predictions of the model, our results provide novel empirical support for kin-selected conflict over resource inheritance.}, }
@article {pmid30718704, year = {2019}, author = {Amici, F and Sánchez-Amaro, A and Sebastián-Enesco, C and Cacchione, T and Allritz, M and Salazar-Bonet, J and Rossano, F}, title = {The word order of languages predicts native speakers' working memory.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {1124}, pmid = {30718704}, issn = {2045-2322}, mesh = {Adolescent ; Adult ; Africa ; Asia ; Comprehension ; Europe ; Female ; Functional Laterality/*physiology ; Humans ; *Language ; Male ; Memory, Short-Term/*physiology ; Speech Perception ; Thinking/*physiology ; Young Adult ; }, abstract = {The relationship between language and thought is controversial. One hypothesis is that language fosters habits of processing information that are retained even in non-linguistic domains. In left-branching (LB) languages, modifiers usually precede the head, and real-time sentence comprehension may more heavily rely on retaining initial information in working memory. Here we presented a battery of working memory and short-term memory tasks to adult native speakers of four LB and four right-branching (RB) languages from Africa, Asia and Europe. In working memory tasks, LB speakers were better than RB speakers at recalling initial stimuli, but worse at recalling final stimuli. Our results show that the practice of parsing sentences in specific directions due to the syntax and word order of our native language not only predicts the way we remember words, but also other non-linguistic stimuli.}, }
@article {pmid30706446, year = {2019}, author = {Grueter, CC and Hale, J and Jin, R and Judge, D and Stoinski, T}, title = {Infant handling by female mountain gorillas: Establishing its frequency, function, and (ir)relevance for life history evolution.}, journal = {American journal of physical anthropology}, volume = {168}, number = {4}, pages = {744-749}, doi = {10.1002/ajpa.23791}, pmid = {30706446}, issn = {1096-8644}, mesh = {Animals ; Animals, Newborn/physiology ; Anthropology, Physical ; Behavior, Animal/*physiology ; Female ; Gorilla gorilla/*physiology ; Maternal Behavior/*physiology ; Rwanda ; }, abstract = {OBJECTIVES: Infant handling describes cases in which youngsters are temporarily removed from the care of their mothers and "taken care of" (held, carried, etc.) by other conspecifics. Handlers may gain indirect fitness benefits from these actions and can practice mothering skills, thereby improving the odds of survival of their own infants. Great apes are notable for displaying little infant handling. Apart from anecdotal observations, no published data exist on infant handling in wild mountain gorillas. We tested two of the most pertinent explanations ("kin selection" and "learning to mother") in a wild population of mountain gorillas in Rwanda. We predicted that (a) nulliparous females would exhibit infant handling (i.e., carrying) more than parous females and (b) maternal kin would exhibit more infant handling than nonkin.<br><br>METHODS: We collated 8 years of data on infant carrying behavior collected in 13 groups monitored by the Dian Fossey Gorilla Fund's Karisoke Research Center.<br><br>RESULTS: Infant handling is an infrequent behavior (1,783 instances over 25,600 observation hours). A strong positive effect of relatedness and handler parity on the frequency of infant handling emerged.<br><br>CONCLUSIONS: While the nature of handler-infant interactions (affiliative, abusive, etc.) remains unstudied, they could constitute alloparental care and could therefore attenuate maternal energetic burden and ultimately allow increased birth rates. However, the rarity of this behavior makes it an unlikely contributor to mountain gorillas' relatively short interbirth intervals.}, }
@article {pmid30700283, year = {2019}, author = {Bose, APH and Henshaw, JM and Zimmermann, H and Fritzsche, K and Sefc, KM}, title = {Inclusive fitness benefits mitigate costs of cuckoldry to socially paired males.}, journal = {BMC biology}, volume = {17}, number = {1}, pages = {2}, pmid = {30700283}, issn = {1741-7007}, support = {P 27605/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Behavior, Animal/*physiology ; Cichlids/physiology ; Female ; Male ; Reproduction/*physiology ; Sexual Behavior, Animal/*physiology ; *Social Behavior ; }, abstract = {BACKGROUND: In socially monogamous species, reproduction is not always confined to paired males and females. Extra-pair males commonly also reproduce with paired females, which is traditionally thought to be costly to the females' social partners. However, we suggest that when the relatedness between reproducing individuals is considered, cuckolded males can suffer lower fitness losses than otherwise expected, especially when the rate of cuckoldry is high. We combine theoretical modeling with a detailed genetic study on a socially monogamous wild fish, Variabilichromis moorii, which displays biparental care despite exceptionally high rates of extra-pair paternity.<br><br>RESULTS: We measured the relatedness between all parties involved in V. moorii spawning events (i.e. between males and females in social pairs, females and their extra-pair partners, and paired males and their cuckolders), and we reveal that males are on average more related to their cuckolders than expected by chance. Queller-Goodnight estimates of relatedness between males and their cuckolders are on average r&#x2009;=&#x2009;0.038 but can range up to r&#x2009;=&#x2009;0.64. This also increases the relatedness between males and the extra-pair offspring under their care. These intriguing results are consistent with the predictions of our mathematical model, which shows that elevated relatedness between paired males and their cuckolders can be adaptive for both parties when competition for fertilizations is strong.<br><br>CONCLUSIONS: Our results show how cuckoldry by relatives can offset males' direct fitness losses with inclusive fitness gains, which can be substantial in systems where males face almost certain paternity losses.}, }
@article {pmid30689139, year = {2019}, author = {Grodwohl, JB}, title = {Animal Behavior, Population Biology and the Modern Synthesis (1955-1985).}, journal = {Journal of the history of biology}, volume = {52}, number = {4}, pages = {597-633}, pmid = {30689139}, issn = {1573-0387}, mesh = {Animals ; *Behavior, Animal ; *Biological Evolution ; Ethology/*history ; Genetics, Population/*history ; History, 20th Century ; Models, Biological ; *Selection, Genetic ; Sociobiology/history ; }, abstract = {This paper examines the history of animal behavior studies after the synthesis period. Three episodes are considered: the adoption of the theory of natural selection, the mathematization of ideas, and the spread of molecular methods in behavior studies. In these three episodes, students of behavior adopted practices and standards developed in population ecology and population genetics. While they borrowed tools and methods from these fields, they made distinct uses (inclusive fitness method, evolutionary theory of games, emphasis on individual selection) that set them relatively apart and led them to contribute, in their own way, to evolutionary theory. These episodes also highlight some limitations of "conjunction narratives" centered on the relation between a discipline and the modern synthesis. A trend in conjunction narratives is to interpret any development related to evolution in a discipline as an "extension," an "integration," or as a "delayed" synthesis. I here suggest that this can lead to underestimate discontinuities in the history of evolutionary biology.}, }
@article {pmid30672052, year = {2019}, author = {Patel, M and Raymond, B and Bonsall, MB and West, SA}, title = {Crystal toxins and the volunteer's dilemma in bacteria.}, journal = {Journal of evolutionary biology}, volume = {32}, number = {4}, pages = {310-319}, pmid = {30672052}, issn = {1420-9101}, support = {BB/M011224/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Bacteria/metabolism ; *Bacterial Physiological Phenomena ; Bacterial Toxins/*biosynthesis/chemistry/toxicity ; Biological Evolution ; Host-Pathogen Interactions/*physiology ; *Models, Biological ; Population Density ; }, abstract = {The growth and virulence of the bacteria Bacillus thuringiensis depend on the production of Cry toxins, which are used to perforate the gut of its host. Successful invasion of the host relies on producing a threshold amount of toxin, after which there is no benefit from producing more toxin. Consequently, the production of Cry toxin appears to be a different type of social problem compared with the public goods scenarios that bacteria usually encounter. We show that selection for toxin production is a volunteer's dilemma. We make specific predictions that (a) selection for toxin production depends upon an interplay between the number of bacterial cells that each host ingests and the genetic relatedness between those cells; (b) cheats that do not produce toxin gain an advantage when at low frequencies, and at high bacterial density, allowing them to be maintained in a population alongside toxin-producing cells. More generally, our results emphasize the diversity of the social games that bacteria play.}, }
@article {pmid30655189, year = {2019}, author = {Barstow, BA and Vice, J and Bowman, S and Mehta, T and Kringen, S and Axelson, P and Padalabalanarayanan, S}, title = {Examining perceptions of existing and newly created accessibility symbols.}, journal = {Disability and health journal}, volume = {12}, number = {2}, pages = {180-186}, doi = {10.1016/j.dhjo.2018.11.012}, pmid = {30655189}, issn = {1876-7583}, mesh = {Adult ; Aged ; Aged, 80 and over ; *Comprehension ; Disabled Persons/*psychology ; *Equipment Design ; Female ; Humans ; *Location Directories and Signs ; Male ; Middle Aged ; Surveys and Questionnaires ; United States ; }, abstract = {BACKGROUND: Symbols are used to convey messages in a clear, understandable manner, without the use of written language. The most widely recognized symbol used to denote access for persons with disabilities is the International Symbol of Access. This symbol has been criticized for its inadequate representation of disability diversity poorly representing universal design of space and products.<br><br>OBJECTIVE: This descriptive study explored individual comprehension and perceptions of nine existing and newly created accessibility pictograph symbols and identified one that represented universal access to fitness equipment.<br><br>METHODS: A survey was disseminated electronically and face-to-face to individuals, groups and organizations affiliated with inclusive fitness equipment, space and programming. Quantitative data was analyzed for descriptive statistics, rank order of symbols and group comparisons of rankings. Thematic analysis of open-ended question results revealed themes to enhance understanding of symbol rank order.<br><br>RESULTS: 981 participants completed the survey. Symbol four, shaped as a Venn diagram containing three icons representing individuals with varying ability levels, was ranked highest with no significant differences in group comparisons between participants with and without a disability and U.S. residents versus non-U.S. residents. 85.4% of participants demonstrated accurate comprehension of this symbol. Though symbol five had the same symbol rank median value, this symbol's distribution of scores was lower.<br><br>CONCLUSIONS: Participants accurately comprehended symbol four and it was identified as the highest ranked symbol representing universal access to fitness equipment. Because of symbol unfamiliarity, adoption will require education and consistency of use and placement.}, }
@article {pmid30639341, year = {2019}, author = {Lohr, JN and Galimov, ER and Gems, D}, title = {Does senescence promote fitness in Caenorhabditis elegans by causing death?.}, journal = {Ageing research reviews}, volume = {50}, number = {}, pages = {58-71}, pmid = {30639341}, issn = {1872-9649}, support = {/WT_/Wellcome Trust/United Kingdom ; 098565/Z/12/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aging/pathology/*physiology ; Animals ; Apoptosis/physiology ; Biological Evolution ; Caenorhabditis elegans/*physiology ; Cellular Senescence/*physiology ; Physical Fitness/*physiology ; }, abstract = {A widely appreciated conclusion from evolutionary theory is that senescence (aging) is of no adaptive value to the individual that it afflicts. Yet studies of Caenorhabditis elegans and Saccharomyces cerevisiae are increasingly revealing the presence of processes which actively cause senescence and death, leading some biogerontologists to wonder about the established theory. Here we argue that programmed death that increases fitness could occur in C. elegans and S. cerevisiae, and that this is consistent with the classic evolutionary theory of aging. This is because of the special conditions under which these organisms have evolved, particularly the existence of clonal populations with limited dispersal and, in the case of C. elegans, the brevity of the reproductive period caused by protandrous hermaphroditism. Under these conditions, death-promoting mechanisms could promote worm fitness by enhancing inclusive fitness, or worm colony fitness through group selection. Such altruistic, adaptive death is not expected to evolve in organisms with outbred, dispersed populations (e.g. most vertebrate species). The plausibility of adaptive death in C. elegans is supported by computer modelling studies, and new knowledge about the ecology of this species. To support these arguments we also review the biology of adaptive death, and distinguish three forms: consumer sacrifice, biomass sacrifice and defensive sacrifice.}, }
@article {pmid30629594, year = {2019}, author = {Narasimha, S and Nagornov, KO and Menin, L and Mucciolo, A and Rohwedder, A and Humbel, BM and Stevens, M and Thum, AS and Tsybin, YO and Vijendravarma, RK}, title = {Drosophila melanogaster cloak their eggs with pheromones, which prevents cannibalism.}, journal = {PLoS biology}, volume = {17}, number = {1}, pages = {e2006012}, pmid = {30629594}, issn = {1545-7885}, mesh = {Alkadienes/*metabolism ; Animals ; Cannibalism ; Drosophila Proteins/metabolism ; Drosophila melanogaster/metabolism ; Female ; Larva ; Ovum/*physiology ; Pheromones/*metabolism ; Predatory Behavior/physiology ; Sexual Behavior, Animal/physiology ; }, abstract = {Oviparous animals across many taxa have evolved diverse strategies that deter egg predation, providing valuable tests of how natural selection mitigates direct fitness loss. Communal egg laying in nonsocial species minimizes egg predation. However, in cannibalistic species, this very behavior facilitates egg predation by conspecifics (cannibalism). Similarly, toxins and aposematic signaling that deter egg predators are often inefficient against resistant conspecifics. Egg cannibalism can be adaptive, wherein cannibals may benefit through reduced competition and added nutrition, but since it reduces Darwinian fitness, the evolution of anticannibalistic strategies is rife. However, such strategies are likely to be nontoxic because deploying toxins against related individuals would reduce inclusive fitness. Here, we report how D. melanogaster use specific hydrocarbons to chemically mask their eggs from cannibal larvae. Using an integrative approach combining behavioral, sensory, and mass spectrometry methods, we demonstrate that maternally provisioned pheromone 7,11-heptacosadiene (7,11-HD) in the eggshell's wax layer deters egg cannibalism. Furthermore, we show that 7,11-HD is nontoxic, can mask underlying substrates (for example, yeast) when coated upon them, and its detection requires pickpocket 23 (ppk23) gene function. Finally, using light and electron microscopy, we demonstrate how maternal pheromones leak-proof the egg, consequently concealing it from conspecific larvae. Our data suggest that semiochemicals possibly subserve in deceptive functions across taxa, especially when predators rely on chemical cues to forage, and stimulate further research on deceptive strategies mediated through nonvisual sensory modules. This study thus highlights how integrative approaches can illuminate our understanding on the adaptive significance of deceptive defenses and the mechanisms through which they operate.}, }
@article {pmid30624681, year = {2019}, author = {Aumer, D and Stolle, E and Allsopp, M and Mumoki, F and Pirk, CWW and Moritz, RFA}, title = {A Single SNP Turns a Social Honey Bee (Apis mellifera) Worker into a Selfish Parasite.}, journal = {Molecular biology and evolution}, volume = {36}, number = {3}, pages = {516-526}, pmid = {30624681}, issn = {1537-1719}, mesh = {Altruism ; Animals ; Bees/*genetics ; Female ; Parthenogenesis/*genetics ; Polymorphism, Single Nucleotide ; Selection, Genetic ; }, abstract = {The evolution of altruism in complex insect societies is arguably one of the major transitions in evolution and inclusive fitness theory plausibly explains why this is an evolutionary stable strategy. Yet, workers of the South African Cape honey bee (Apis mellifera capensis) can reverse to selfish behavior by becoming social parasites and parthenogenetically producing female offspring (thelytoky). Using a joint mapping and population genomics approach, in combination with a time-course transcript abundance dynamics analysis, we show that a single nucleotide polymorphism at the mapped thelytoky locus (Th) is associated with the iconic thelytokous phenotype. Th forms a linkage group with the ecdysis-triggering hormone receptor (Ethr) within a nonrecombining region under strong selection in the genome. A balanced detrimental allele system plausibly explains why the trait is specific to A. m. capensis and cannot easily establish itself into genomes of other honey bee subspecies.}, }
@article {pmid30564400, year = {2018}, author = {Hare, D and Blossey, B and Reeve, HK}, title = {Value of species and the evolution of conservation ethics.}, journal = {Royal Society open science}, volume = {5}, number = {11}, pages = {181038}, pmid = {30564400}, issn = {2054-5703}, abstract = {The theory of evolution by natural selection can help explain why people care about other species. Building upon recent insights that morality evolves to secure fitness advantages of cooperation, we propose that conservation ethics (moral beliefs, attitudes, intuitions and norms regarding other species) could be adaptations that support cooperation between humans and non-humans. We present eco-evolutionary cost-benefit models of conservation behaviours as interspecific cooperation (altruism towards members of other species). We find that an evolutionary rule identical in structure to Hamilton's rule (which explains altruistic behaviour towards related conspecifics) can explain altruistic behaviour towards members of other species. Natural selection will favour traits for selectively altering the success of members of other species (e.g. conserving them) in ways that maximize inclusive fitness return benefits. Conservation behaviours and the ethics that evolve to reinforce them will be sensitive to local ecological and socio-cultural conditions, so will assume different contours in different places. Difficulties accurately assessing costs and benefits provided by other species, time required to adapt to ecological and socio-cultural change and barriers to collective action could explain the apparent contradiction between the widespread existence of conservation ethics and patterns of biodiversity decline globally.}, }
@article {pmid30557568, year = {2019}, author = {Eshel, I}, title = {Mutual altruism and long-term optimization of the inclusive fitness in multilocus genetic systems.}, journal = {Theoretical population biology}, volume = {129}, number = {}, pages = {126-132}, doi = {10.1016/j.tpb.2018.10.005}, pmid = {30557568}, issn = {1096-0325}, mesh = {*Altruism ; *Genetic Fitness ; *Genetics, Population ; Humans ; Models, Statistical ; *Population Dynamics ; }, abstract = {The dynamics of long-term evolution in a complex genetically-structured population with a flux of random mutations is employed here to study the evolution of mutual altruism between relatives that are encountered repeatedly, where the level of altruism is measured by the risk one is willing to accept in order to save the life of one's relative. It is shown that regardless of the number of loci involved, of the rates of recombination among them, and of the intensity of the selection forces, the long-term dynamics can phenotypically converge only to a level of altruism that maximizes the individual inclusive fitness as it has previously defined by students of the individual approach to evolution. Except for the widely studied case of weak selection, however, the convergence to such a level of altruism is not necessarily generation-to-next monotone. It is further shown that, unlike the case of the one-shot encounter, repeated encounters between relatives allow for more than one level of altruism which may maximize the inclusive fitness, in which case not all such levels of altruism are evolutionarily accessible.}, }
@article {pmid30464831, year = {2018}, author = {Clarke, PMR and McElreath, MB and Barrett, BJ and Mabry, KE and McElreath, R}, title = {The evolution of bequeathal in stable habitats.}, journal = {Ecology and evolution}, volume = {8}, number = {21}, pages = {10594-10607}, pmid = {30464831}, issn = {2045-7758}, abstract = {Adults sometimes disperse, while philopatric offspring inherit the natal site, a pattern known as bequeathal. Despite a decades-old empirical literature, little theoretical work has explored when natural selection may favor bequeathal. We present a simple mathematical model of the evolution of bequeathal in a stable environment, under both global and local dispersal. We find that natural selection favors bequeathal when adults are competitively advantaged over juveniles, baseline mortality is high, the environment is unsaturated, and when juveniles experience high dispersal mortality. However, frequently bequeathal may not evolve, because the fitness cost for the adult is too large relative to inclusive fitness benefits. Additionally, there are many situations for which bequeathal is an ESS, yet cannot invade the population. As bequeathal in real populations appears to be facultative, yet-to-be-modeled factors like timing of birth in the breeding season may strongly influence the patterns seen in natural populations.}, }
@article {pmid30457220, year = {2019}, author = {Amici, F}, title = {An Evolutionary Approach to the Study of Collaborative Remembering?.}, journal = {Topics in cognitive science}, volume = {11}, number = {4}, pages = {811-816}, doi = {10.1111/tops.12398}, pmid = {30457220}, issn = {1756-8765}, mesh = {Adaptation, Psychological/physiology ; Biological Evolution ; *Cooperative Behavior ; Humans ; Knowledge ; Memory/*physiology ; Mental Recall/*physiology ; Social Behavior ; Social Learning/physiology ; }, abstract = {Hope and Gabbert (2008) and Jay and colleagues (in press) show us that collaborative remembering, in certain contexts, may result in incomplete and less accurate memories. Here, I will discuss the evolutionary origins of this behavior, linking it to phenomena such as social contagion, conformity, and social learning, which are highly adaptive and widespread across non-human taxa.}, }
@article {pmid30455506, year = {2018}, author = {Ruiz-Lambides, AV and Weiß, BM and Kulik, L and Widdig, A}, title = {Which male and female characteristics influence the probability of extragroup paternities in rhesus macaques, Macaca mulatta?.}, journal = {Animal behaviour}, volume = {140}, number = {}, pages = {119-127}, pmid = {30455506}, issn = {0003-3472}, support = {P40 OD012217/OD/NIH HHS/United States ; }, abstract = {Extragroup paternity (EGP) is found across a wide range of species and may entail reproductive benefits, but may also entail costs to both sexes. While population and group parameters affecting the degree of EGPs are relatively well established, less is known about the individual characteristics that make males and females engage in alternative reproductive tactics such as EGP. Applying a combination of long-term demographic and genetic data from the rhesus macaque population of Cayo Santiago (Puerto Rico, U.S.A.), we investigate which male and female characteristics influence the probability of EGP to better understand the circumstances that shape the distribution and occurrence of EGP. Our results show that, against our expectations, higher-ranking females were more likely to produce EGP offspring than lower- ranking females. The probability of producing extragroup offspring was not significantly related to female or male age, male tenure or previous reproductive success. Furthermore, genetic relatedness between the parents did not affect the production of extragroup offspring, but extragroup offspring were more frequently produced early rather than late in a given mating season. Altogether, our analysis suggests that individual attributes and seasonal aspects create different opportunities and preferences for engaging in EGP as an alternative reproductive tactic. The observed patterns of EGP in rhesus macaques appear to be consistent with female mate choice for genetic benefits, which needs to be confirmed in future studies.}, }
@article {pmid30450066, year = {2018}, author = {Antfolk, J and Lieberman, D and Harju, C and Albrecht, A and Mokros, A and Santtila, P}, title = {Opposition to Inbreeding Between Close Kin Reflects Inclusive Fitness Costs.}, journal = {Frontiers in psychology}, volume = {9}, number = {}, pages = {2101}, pmid = {30450066}, issn = {1664-1078}, abstract = {Due to the intense selection pressure against inbreeding, humans are expected to possess psychological adaptations that regulate mate choice and avoid inbreeding. From a gene's-eye perspective, there is little difference in the evolutionary costs between situations where an individual him/herself is participating in inbreeding and inbreeding among other close relatives. The difference is merely quantitative, as fitness can be compromised via both routes. The question is whether humans are sensitive to the direct as well as indirect costs of inbreeding. Using responses from a large population-based sample (27,364 responses from 2,353 participants), we found that human motivations to avoid inbreeding closely track the theoretical costs of inbreeding as predicted by inclusive fitness theory. Participants were asked to select in a forced choice paradigm, which of two acts of inbreeding with actual family members they would want to avoid most. We found that the estimated fitness costs explained 83.6% of participant choices. Importantly, fitness costs explained choices also when the self was not involved. We conclude that humans intuit the indirect fitness costs of mating decisions made by close family members and that psychological inbreeding avoidance mechanisms extend beyond self-regulation.}, }
@article {pmid30444662, year = {2018}, author = {Mullon, C and Lehmann, L}, title = {Eco-Evolutionary Dynamics in Metacommunities: Ecological Inheritance, Helping within Species, and Harming between Species.}, journal = {The American naturalist}, volume = {192}, number = {6}, pages = {664-686}, doi = {10.1086/700094}, pmid = {30444662}, issn = {1537-5323}, mesh = {Altruism ; Animals ; *Biological Evolution ; *Biota ; Demography ; Ecosystem ; Models, Theoretical ; Population Dynamics ; Selection, Genetic ; }, abstract = {Understanding selection on intra- and interspecific interactions that take place in dispersal-limited communities is a challenge for ecology and evolutionary biology. The problem is that local demographic stochasticity generates eco-evolutionary dynamics that are generally too complicated to make tractable analytical investigations. Here we circumvent this problem by approximating the selection gradient on a quantitative trait that influences local community dynamics, assuming that such dynamics are deterministic with a stable fixed point. The model nonetheless captures unavoidable kin selection effects arising from demographic stochasticity. Our approximation reveals that selection depends on how an individual expressing a trait change influences (1) its own fitness and the fitness of its current relatives and (2) the fitness of its downstream relatives through modifications of local ecological conditions (i.e., through ecological inheritance). Mathematically, the effects of ecological inheritance on selection are captured by dispersal-limited versions of press perturbations of community ecology. We use our approximation to investigate the evolution of helping within species and harming between species when these behaviors influence demography. We find that altruistic helping evolves more readily when intraspecific competition is for material resources rather than for space, because in this case the costs of kin competition tend to be paid by downstream relatives. Similarly, altruistic harming between species evolves when it alleviates downstream relatives from interspecific competition. Beyond these examples, our approximation can help better understand the influence of ecological inheritance on a variety of eco-evolutionary dynamics in metacommunities, from consumer-resource and predator-prey coevolution to selection on mating systems with demographic feedbacks.}, }
@article {pmid30417945, year = {2019}, author = {Thomson, CE and Hadfield, JD}, title = {No evidence for sibling or parent-offspring coadaptation in a wild population of blue tits, despite high power.}, journal = {Evolution; international journal of organic evolution}, volume = {73}, number = {1}, pages = {28-41}, pmid = {30417945}, issn = {1558-5646}, support = {//EPSRC/International ; UF150696//Royal Society/International ; UF100660//Royal Society/International ; NE/F015275/1//Natural Environment Research Council/International ; NE/P000924/1//Natural Environment Research Council/International ; }, mesh = {Animals ; Female ; Male ; *Maternal Behavior ; *Paternal Behavior ; *Reproduction ; *Siblings ; Songbirds/*physiology ; }, abstract = {Parent and offspring behaviors are expected to act as both the agents and targets of selection. This may generate parent-offspring coadaptation in which parent and offspring behaviors become genetically correlated in a way that increases inclusive fitness. Cross-fostering has been used to study parent-offspring coadaptation, with the prediction that offspring raised by non-relatives, or parents raising non-relatives, should suffer fitness costs. Using long-term data from more than 400 partially crossed broods of blue tits (Cyanistes caeruleus), we show that there is no difference in mass or survival between crossed and non-crossed chicks. However, previous studies for which the evidence for parent-offspring coadaptation is strongest compare chicks from fully crossed broods with those from non-crossed broods. When parent-offspring coadaptation acts at the level of the brood then partial cross-fostering experiments are not expected to show evidence of coadaptation. To test this, we performed an additional experiment (163 broods) in which clutches were either fully crossed, non-crossed, or partially crossed. In agreement with the long-term data, there was no evidence for parent-offspring coadaptation on offspring fitness despite high power. In addition there was no evidence of effects on parental fitness, nor evidence of sibling coadaptation, although the power of these tests was more modest.}, }
@article {pmid30401742, year = {2018}, author = {Wang, C and Lu, X}, title = {Reply to Engelhardt et al.: Inclusive fitness does maintain a heritable altruism polymorphism in Tibetan ground tits.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {48}, pages = {E11210-E11211}, pmid = {30401742}, issn = {1091-6490}, mesh = {*Altruism ; Game Theory ; *Genetic Fitness ; Tibet ; }, }
@article {pmid30397131, year = {2018}, author = {Green, JP and Hatchwell, BJ}, title = {Inclusive fitness consequences of dispersal decisions in a cooperatively breeding bird, the long-tailed tit (Aegithalos caudatus).}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {47}, pages = {12011-12016}, pmid = {30397131}, issn = {1091-6490}, mesh = {Animal Migration/*physiology ; Animals ; Behavior, Animal/physiology ; Biological Evolution ; Breeding ; Cooperative Behavior ; Female ; Gene Flow/physiology ; Male ; Mating Preference, Animal/*physiology ; Passeriformes/physiology ; Population Dynamics ; Reproduction ; Sexual Behavior, Animal/*physiology ; Songbirds/physiology ; }, abstract = {Natal dispersal is a demographic trait with profound evolutionary, ecological, and behavioral consequences. However, our understanding of the adaptive value of dispersal patterns is severely hampered by the difficulty of measuring the relative fitness consequences of alternative dispersal strategies in natural populations. This is especially true in social species, in which natal philopatry allows kin selection to operate, so direct and indirect components of inclusive fitness have to be considered when evaluating selection on dispersal. Here, we use lifetime reproductive success data from a long-term study of a cooperative breeder, the long-tailed tit Aegithalos caudatus, to quantify the direct and indirect components of inclusive fitness. We show that dispersal has a negative effect on the accrual of indirect fitness, and hence inclusive fitness, by males. In contrast, the inclusive, predominantly direct, fitness of females increases with dispersal distance. We conclude that the conflicting fitness consequences of dispersal in this species result in sexually antagonistic selection on this key demographic parameter.}, }
@article {pmid30381383, year = {2018}, author = {Macfarlan, SJ and Erickson, PI and Yost, J and Regalado, J and Jaramillo, L and Beckerman, S}, title = {Bands of brothers and in-laws: Waorani warfare, marriage and alliance formation.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1890}, pages = {}, pmid = {30381383}, issn = {1471-2954}, mesh = {Adolescent ; Adult ; Anthropology, Cultural ; Child ; *Cooperative Behavior ; Ecuador ; Family ; Female ; Humans ; Male ; Marriage/*psychology ; Middle Aged ; Warfare/*psychology ; }, abstract = {The root of modern human warfare lies in the lethal coalitionary violence of males in small-scale societies. However, there is a paucity of quantitative data concerning the form and function of coalitionary violence in this setting. Debates exist over how lethal coalitions are constituted, as well as the motivations and benefits for males to join such groups. Data from a lowland Amazonian population, the Waorani of Ecuador, illuminate three issues: (i) the degree to which raiding parties are composed of groups of fraternal kin as opposed to strategic alliances of actual or potential affinal kin; (ii) the extent to which individuals use pre-existing affinal ties to motivate others to participate in war or leverage warfare as a mechanism to create such ties; and (iii) the extent to which participation in raiding is driven by rewards associated with future marriage opportunities. Analyses demonstrate that Waorani raiding parties were composed of a mix of males who were potential affines, actual affines and fraternal kin, suggesting that men used pre-existing genetic, lineal and social kin ties for recruiting raid partners and used raiding as a venue to create novel social relationships. Furthermore, analyses demonstrate that males leveraged raiding alliances to achieve marriage opportunities for themselves as well as for their children. Overall, it appears that a complex set of motivations involving individual rewards, kin marriage opportunities, subtle coercion and the assessment of alliance strength promote violent intergroup conflict among the Waorani. These findings illustrate the complex inter-relationships among kin selection, coalition building and mating success in our species.}, }
@article {pmid30381376, year = {2018}, author = {Holen, &#xd8;H and Johnstone, RA}, title = {Reciprocal mimicry: kin selection can drive defended prey to resemble their Batesian mimics.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1890}, pages = {}, pmid = {30381376}, issn = {1471-2954}, mesh = {Animals ; *Biological Evolution ; Biological Mimicry/*genetics ; Models, Biological ; *Predatory Behavior ; Selection, Genetic ; }, abstract = {Established mimicry theory predicts that Batesian mimics are selected to resemble their defended models, while models are selected to become dissimilar from their mimics. However, this theory has mainly considered individual selection acting on solitary organisms such as adult butterflies. Although Batesian mimicry of social insects is common, the few existing applications of kin selection theory to mimicry have emphasized relatedness among mimics rather than among models. Here, we present a signal detection model of Batesian mimicry in which the population of defended model prey is kin structured. Our analysis shows for most of parameter space that increased average dissimilarity from mimics has a twofold group-level cost for the model prey: it attracts more predators and these adopt more aggressive attack strategies. When mimetic resemblance and local relatedness are sufficiently high, such costs acting in the local neighbourhood may outweigh the individual benefits of dissimilarity, causing kin selection to drive the models to resemble their mimics. This requires model prey to be more common than mimics and/or well-defended, the conditions under which Batesian mimicry is thought most successful. Local relatedness makes defended prey easier targets for Batesian mimicry and is likely to stabilize the mimetic relationship over time.}, }
@article {pmid30380919, year = {2018}, author = {Hernández Blasi, C and Mondéjar, L}, title = {Testing the Kundera Hypothesis: Does Every Woman (But Not Every Man) Prefer Her Child to Her Mate?.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {16}, number = {4}, pages = {1474704918808864}, pmid = {30380919}, issn = {1474-7049}, mesh = {Adult ; *Altruism ; Choice Behavior/*physiology ; Female ; Humans ; *Interpersonal Relations ; Male ; Maternal Behavior/*physiology ; *Morals ; *Parent-Child Relations ; *Sexual Partners ; Young Adult ; }, abstract = {The context of a famous novel by Milan Kundera (Immortality) suggests that when faced with a life-or-death situation, every woman would prefer to save her child than her husband, left hanging whether every man would do the same. We labeled this as the Kundera hypothesis, and the purpose of this study was to test it empirically as we believe it raises a thought-provoking question in evolutionary terms. Specifically, 197 college students (92 women) were presented a questionnaire where they had to make different decisions about four dilemmas about who to save (their mate or their offspring) in two hypothetical life-or-death situations: a home fire and a car crash. These dilemmas involved two different mate ages (a 25- or a 40-year-old mate) and two offspring ages (1- or a 6-year-old child). For comparative purposes, we also included complementary life-or-death dilemmas on both a sibling and an offspring, and a sibling and a cousin. The results generally supported the Kundera hypothesis: Although the majority of men and women made the decision to save their offspring instead of their mate, about 18% of men on average (unlike the 5% of women) consistently decided to save their mate across the four dilemmas in the two life-or-death situations. These data were interpreted with reference to Hamilton's inclusive fitness theory, the preferential role of women as kin keepers, and the evolution of altruism toward friends and mates.}, }
@article {pmid30372557, year = {2018}, author = {Fortuna, TM and Namias, A and Snirc, A and Branca, A and Hood, ME and Raquin, C and Shykoff, JA and Giraud, T}, title = {Multiple infections, relatedness and virulence in the anther-smut fungus castrating Saponaria plants.}, journal = {Molecular ecology}, volume = {27}, number = {23}, pages = {4947-4959}, doi = {10.1111/mec.14911}, pmid = {30372557}, issn = {1365-294X}, mesh = {Basidiomycota/*genetics/*pathogenicity ; Flowers/microbiology ; Genetic Variation ; Genotype ; Microsatellite Repeats ; Plant Diseases/*microbiology ; Plant Infertility ; Saponaria/genetics/*microbiology ; Virulence ; }, abstract = {Multiple infections (co-occurrence of multiple pathogen genotypes within an individual host) can have important impacts on diseases. Relatedness among pathogens can affect the likelihood of multiple infections and their consequences through kin selection. Previous studies on the castrating anther-smut fungus Microbotryum lychnidis-dioicae have shown that multiple infections occur in its host plant Silene latifolia. Relatedness was high among fungal genotypes within plants, which could result from competitive exclusion between unrelated fungal genotypes, from population structure or from interactions between plant and fungal genotypes for infection ability. Here, we aimed at disentangling these hypotheses using M. saponariae and its host Saponaria officinalis, both experimentally tractable for these questions. By analysing populations using microsatellite markers, we also found frequent occurrence of multiple infections and high relatedness among strains within host plants. Infections resulting from experimental inoculations in the greenhouse also revealed high relatedness among strains co-infecting host plants, even in clonally replicated plant genotypes, indicating that high relatedness within plants did not result merely from plant x fungus interactions or population structure. Furthermore, hyphal growth in vitro was affected by the presence of a competitor growing nearby and by its genetic similarity, although this latter effect was strain-dependent. Altogether, our results support the hypothesis that relatedness-dependent competitive exclusion occurs in Microbotryum fungi within plants. These microorganisms can thus respond to competitors and to their level of relatedness.}, }
@article {pmid30359363, year = {2018}, author = {Dos Santos, M and Ghoul, M and West, SA}, title = {Pleiotropy, cooperation, and the social evolution of genetic architecture.}, journal = {PLoS biology}, volume = {16}, number = {10}, pages = {e2006671}, pmid = {30359363}, issn = {1545-7885}, mesh = {Computer Simulation ; *Evolution, Molecular ; *Genetic Pleiotropy/physiology ; Genotype ; Microbial Interactions/*genetics/physiology ; Microbiota/*genetics/physiology ; *Models, Genetic ; Mutation ; }, abstract = {Pleiotropy has been suggested as a novel mechanism for stabilising cooperation in bacteria and other microbes. The hypothesis is that linking cooperation with a trait that provides a personal (private) benefit can outweigh the cost of cooperation in situations when cooperation would not be favoured by mechanisms such as kin selection. We analysed the theoretical plausibility of this hypothesis, with analytical models and individual-based simulations. We found that (1) pleiotropy does not stabilise cooperation, unless the cooperative and private traits are linked via a genetic architecture that cannot evolve (mutational constraint); (2) if the genetic architecture is constrained in this way, then pleiotropy favours any type of trait and not especially cooperation; (3) if the genetic architecture can evolve, then pleiotropy does not favour cooperation; and (4) there are several alternative explanations for why traits may be linked, and causality can even be predicted in the opposite direction, with cooperation favouring pleiotropy. Our results suggest that pleiotropy could only explain cooperation under restrictive conditions and instead show how social evolution can shape the genetic architecture.}, }
@article {pmid30353655, year = {2019}, author = {Li, XY and Kokko, H}, title = {Sex-biased dispersal: a review of the theory.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {94}, number = {2}, pages = {721-736}, pmid = {30353655}, issn = {1469-185X}, mesh = {Animal Distribution/*physiology ; Animals ; Biological Evolution ; Female ; Genetic Fitness ; Inbreeding ; Male ; *Sex Characteristics ; Sex Factors ; Sex Ratio ; Sexual Behavior, Animal ; }, abstract = {Dispersal is ubiquitous throughout the tree of life: factors selecting for dispersal include kin competition, inbreeding avoidance and spatiotemporal variation in resources or habitat suitability. These factors differ in whether they promote male and female dispersal equally strongly, and often selection on dispersal of one sex depends on how much the other disperses. For example, for inbreeding avoidance it can be sufficient that one sex disperses away from the natal site. Attempts to understand sex-specific dispersal evolution have created a rich body of theoretical literature, which we review here. We highlight an interesting gap between empirical and theoretical literature. The former associates different patterns of sex-biased dispersal with mating systems, such as female-biased dispersal in monogamous birds and male-biased dispersal in polygynous mammals. The predominant explanation is traceable back to Greenwood's () ideas of how successful philopatric or dispersing individuals are at gaining mates or the resources required to attract them. Theory, however, has developed surprisingly independently of these ideas: models typically track how immigration and emigration change relatedness patterns and alter competition for limiting resources. The limiting resources are often considered sexually distinct, with breeding sites and fertilizable females limiting reproductive success for females and males, respectively. We show that the link between mating system and sex-biased dispersal is far from resolved: there are studies showing that mating systems matter, but the oft-stated association between polygyny and male-biased dispersal is not a straightforward theoretical expectation. Here, an important understudied factor is the extent to which movement is interpretable as an extension of mate-searching (e.g. are matings possible en route or do they only happen after settling in new habitat - or can females perhaps move with stored sperm). We also point out other new directions for bridging the gap between empirical and theoretical studies: there is a need to build Greenwood's influential yet verbal explanation into formal models, which also includes the possibility that an individual benefits from mobility as it leads to fitness gains in more than one final breeding location (a possibility not present in models with a very rigid deme structure). The order of life-cycle events is likewise important, as this impacts whether a departing individual leaves behind important resources for its female or male kin, or perhaps both, in the case of partially overlapping resource use.}, }
@article {pmid30338460, year = {2019}, author = {Amici, F}, title = {Memories of emotional expressions in horses.}, journal = {Learning &amp; behavior}, volume = {47}, number = {3}, pages = {191-192}, pmid = {30338460}, issn = {1543-4508}, mesh = {Animals ; Attention ; Horses ; Humans ; Interpersonal Relations ; *Memory ; *Mental Recall ; }, abstract = {Proops, Grounds, Smith, and McComb (2018) suggest that horses remember previous emotional expressions of specific humans, and use these memories to adjust their behavior in future social interactions. Despite some methodological shortcomings, this study raises important questions on the complexity of social interactions in nonhuman animals, which surely deserve further attention.}, }
@article {pmid30320554, year = {2018}, author = {van Veelen, M}, title = {Can Hamilton's rule be violated?.}, journal = {eLife}, volume = {7}, number = {}, pages = {}, pmid = {30320554}, issn = {2050-084X}, mesh = {*Altruism ; *Models, Biological ; *Models, Statistical ; }, abstract = {How generally Hamilton's rule holds is a much debated question. The answer to that question depends on how costs and benefits are defined. When using the regression method to define costs and benefits, there is no scope for violations of Hamilton's rule. We introduce a general model for assortative group compositions to show that, when using the counterfactual method for computing costs and benefits, there is room for violations. The model also shows that there are limitations to observing violations in equilibrium, as the discrepancies between Hamilton's rule and the direction of selection may imply that selection will take the population out of the region of disagreement, precluding observations of violations in equilibrium. Given what it takes to create a violation, empirical tests of Hamilton's rule, both in and out of equilibrium, require the use of statistical models that allow for identifying non-linearities in the fitness function.}, }
@article {pmid30310732, year = {2018}, author = {Rodrigues, AMM}, title = {Resource availability and adjustment of social behaviour influence patterns of inequality and productivity across societies.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5488}, pmid = {30310732}, issn = {2167-8359}, abstract = {Animal societies vary widely in the diversity of social behaviour and the distribution of reproductive shares among their group members. It has been shown that individual condition can lead to divergent social roles and that social specialisation can cause an exacerbation or a mitigation of the inequality among group members within a society. This work, however, has not investigated cases in which resource availability varies between different societies, a factor that is thought to explain variation in the level of cooperation and the disparities in reproductive shares within each social group. In this study, I focus on how resource availability mediates the expression of social behaviour and how this, in turn, mediates inequality both within and between groups. I find that when differences in resource availability between societies persist over time, resource-rich societies become more egalitarian. Because lower inequality improves the productivity of a society, the inequality between resource-rich and resource-poor societies rises. When resource availability fluctuates over time, resource-rich societies tend to become more unequal. Because inequality hinders the productivity of a society, the inequality between resource-rich and resource-poor societies falls. From the evolutionary standpoint, my results show that spatial and temporal variation in resource availability may exert a strong influence on the level of inequality both within and between societies.}, }
@article {pmid30306126, year = {2018}, author = {Ohkubo, Y and Yamamoto, T and Ogusu, N and Watanabe, S and Murakami, Y and Yagi, N and Hasegawa, E}, title = {The benefits of grouping as a main driver of social evolution in a halictine bee.}, journal = {Science advances}, volume = {4}, number = {10}, pages = {e1700741}, pmid = {30306126}, issn = {2375-2548}, mesh = {Animals ; Bees ; Behavior, Animal/*physiology ; Diploidy ; Female ; Flight, Animal ; Genetic Fitness ; Haploidy ; Japan ; Male ; Models, Biological ; Nesting Behavior ; *Social Behavior ; Time Factors ; }, abstract = {Over the past decade, the cause of sociality has been much debated. Inclusive fitness [br in Hamilton's rule (br - c > 0)] has been criticized but is still useful in the organization of a framework by elucidating mechanisms through which br (benefit × relatedness) becomes larger than c (cost). The bee Lasioglossum baleicum is suitable for investigation of this issue because of the sympatric occurrence of both social and solitary nesting in its populations. We show that a large part (approximately 92%) of the inclusive fitness of a eusocial worker can be attributed to the benefits of grouping. A 1.5-fold relatedness asymmetry benefit in singly mated haplo-diploids explains a small part (approximately 8.5%) of the observed inclusive fitness. Sociality enables this species to conduct foraging and nest defense simultaneously, which is not the case in solitary nests. Our results indicate that this benefit of grouping is the main source of the increased inclusive fitness of eusocial workers.}, }
@article {pmid30305461, year = {2018}, author = {Dyble, M and Gardner, A and Vinicius, L and Migliano, AB}, title = {Inclusive fitness for in-laws.}, journal = {Biology letters}, volume = {14}, number = {10}, pages = {}, pmid = {30305461}, issn = {1744-957X}, mesh = {Altruism ; Cooperative Behavior ; *Family ; Female ; *Genetic Fitness ; Humans ; Male ; Reproduction ; *Selection, Genetic ; *Social Behavior ; }, abstract = {Cooperation among kin is common across the natural world and can be explained in terms of inclusive fitness theory, which holds that individuals can derive indirect fitness benefits from aiding genetically related individuals. However, human kinship includes not only genetic kin but also kin by marriage: our affines (in-laws) and spouses. Can cooperation between these genetically unrelated kin be reconciled with inclusive fitness theory? Here, we argue that although affinal kin and spouses do not necessarily share genetic ancestry, they may have shared genetic interests in future reproduction and, as such, can derive indirect fitness benefits though cooperating. We use standard inclusive fitness theory to derive a coefficient of shared reproductive interest (s) that predicts altruistic investment both in genetic kin and in spouses and affines. Specifically, a behaviour that reduces the fitness of the actor by c and increases the fitness of the recipient by b will be favoured by natural selection when sb > c We suggest that the coefficient of shared reproductive interest may provide a valuable tool for understanding not only the evolution of human kinship but also cooperation and conflict across the natural world more generally.}, }
@article {pmid30272235, year = {2018}, author = {Minkner, MMI and Young, C and Amici, F and McFarland, R and Barrett, L and Grobler, JP and Henzi, SP and Widdig, A}, title = {Assessment of Male Reproductive Skew via Highly Polymorphic STR Markers in Wild Vervet Monkeys, Chlorocebus pygerythrus.}, journal = {The Journal of heredity}, volume = {109}, number = {7}, pages = {780-790}, doi = {10.1093/jhered/esy048}, pmid = {30272235}, issn = {1465-7333}, mesh = {Animals ; Chlorocebus aethiops/*genetics/*physiology ; Female ; *Genetic Markers ; Heterozygote ; Male ; Microsatellite Repeats/*genetics ; *Polymorphism, Genetic ; Reproduction/*genetics ; Seasons ; South Africa ; }, abstract = {Male reproductive strategies have been well studied in primate species where the ability of males to monopolize reproductive access is high. Less is known about species where males cannot monopolize mating access. Vervet monkeys (Chlorocebus pygerythrus) are interesting in this regard as female codominance reduces the potential for male monopolization. Under this condition, we assessed whether male dominance rank still influences male mating and reproductive success, by assigning paternities to infants in a population of wild vervets in the Eastern Cape, South Africa. To determine paternity, we established microsatellite markers from noninvasive fecal samples via cross-species amplification. In addition, we evaluated male mating and reproductive success for 3 groups over 4 mating seasons. We identified 21 highly polymorphic microsatellites (number of alleles = 7.5 ± 3.1 [mean ± SD], observed heterozygosity = 0.691 ± 0.138 [mean ± SD]) and assigned paternity to 94 of 97 sampled infants (96.9%) with high confidence. Matings pooled over 4 seasons were significantly skewed across 3 groups, although skew indices were low (B index = 0.023-0.030) and mating success did not correlate with male dominance. Paternities pooled over 4 seasons were not consistently significantly skewed (B index = 0.005-0.062), with high-ranking males siring more offspring than subordinates only in some seasons. We detected 6 cases of extra-group paternity (6.4%) and 4 cases of natal breeding (4.3%). Our results suggest that alternative reproductive strategies besides priority of access for dominant males are likely to affect paternity success, warranting further investigation into the determinants of paternity among species with limited male monopolization potential.}, }
@article {pmid30225081, year = {2018}, author = {Konrad, CM and Gero, S and Frasier, T and Whitehead, H}, title = {Kinship influences sperm whale social organization within, but generally not among, social units.}, journal = {Royal Society open science}, volume = {5}, number = {8}, pages = {180914}, pmid = {30225081}, issn = {2054-5703}, abstract = {Sperm whales have a multi-level social structure based upon long-term, cooperative social units. What role kinship plays in structuring this society is poorly understood. We combined extensive association data (518 days, during 2005-2016) and genetic data (18 microsatellites and 346 bp mitochondrial DNA (mtDNA) control region sequences) for 65 individuals from 12 social units from the Eastern Caribbean to examine patterns of kinship and social behaviour. Social units were clearly matrilineally based, evidenced by greater relatedness within social units (mean r = 0.14) than between them (mean r = 0.00) and uniform mtDNA haplotypes within social units. Additionally, most individuals (82.5%) had a first-degree relative in their social unit, while we found no first-degree relatives between social units. Generally and within social units, individuals associated more with their closer relatives (matrix correlations: 0.18-0.25). However, excepting a highly related pair of social units that merged over the study period, associations between social units were not correlated with kinship (p > 0.1). These results are the first to robustly demonstrate kinship's contribution to social unit composition and association preferences, though they also reveal variability in association preferences that is unexplained by kinship. Comparisons with other matrilineal species highlight the range of possible matrilineal societies and how they can vary between and even within species.}, }
@article {pmid30222228, year = {2019}, author = {Townsend, AK and Taff, CC and Jones, ML and Getman, KH and Wheeler, SS and Hinton, MG and Logsdon, RM}, title = {Apparent inbreeding preference despite inbreeding depression in the American crow.}, journal = {Molecular ecology}, volume = {28}, number = {5}, pages = {1116-1126}, doi = {10.1111/mec.14866}, pmid = {30222228}, issn = {1365-294X}, support = {(13-2735)//ANR Competitive Grant from the University of California at Davis/International ; 1555754//National Science Foundation/International ; }, mesh = {Animals ; California ; Crows/*genetics/physiology ; Heterozygote ; Inbreeding ; Inbreeding Depression/*genetics ; Microsatellite Repeats/*genetics ; New York ; Reproduction/*genetics ; Sexual Behavior, Animal ; }, abstract = {Although matings between relatives can have negative effects on offspring fitness, apparent inbreeding preference has been reported in a growing number of systems, including those with documented inbreeding depression. Here, we examined evidence for inbreeding depression and inbreeding preference in two populations (Clinton, New York, and Davis, California, USA) of the cooperatively breeding American crow (Corvus brachyrhynchos). We then compared observed inbreeding strategies with theoretical expectations for optimal, adaptive levels of inbreeding, given the inclusive fitness benefits and population-specific magnitude of inbreeding depression. We found that low heterozygosity at a panel of 33 microsatellite markers was associated with low survival probability (fledging success) and low white blood cell counts among offspring in both populations. Despite these costs, our data were more consistent with inbreeding preference than avoidance: The observed heterozygosity among 396 sampled crow offspring was significantly lower than expected if local adults were mating by random chance. This pattern was consistent across a range of spatial scales in both populations. Adaptive levels of inbreeding, given the magnitude of inbreeding depression, were predicted to be very low in the California population, whereas complete disassortative mating was predicted in the New York population. Sexual conflict might have contributed to the apparent absence of inbreeding avoidance in crows. These data add to an increasing number of examples of an "inbreeding paradox," where inbreeding appears to be preferred despite inbreeding depression.}, }
@article {pmid30210320, year = {2018}, author = {Neupert, S and Hornung, M and Grenwille Millar, J and Kleineidam, CJ}, title = {Learning Distinct Chemical Labels of Nestmates in Ants.}, journal = {Frontiers in behavioral neuroscience}, volume = {12}, number = {}, pages = {191}, pmid = {30210320}, issn = {1662-5153}, abstract = {Colony coherence is essential for eusocial insects because it supports the inclusive fitness of colony members. Ants quickly and reliably recognize who belongs to the colony (nestmates) and who is an outsider (non-nestmates) based on chemical recognition cues (cuticular hydrocarbons: CHCs) which as a whole constitute a chemical label. The process of nestmate recognition often is described as matching a neural template with the label. In this study, we tested the prevailing view that ants use commonalities in the colony odor that are present in the CHC profile of all individuals of a colony or whether different CHC profiles are learned independently. We created and manipulated sub-colonies by adding one or two different hydrocarbons that were not present in the original colony odor of our Camponotus floridanus colony and later tested workers of the sub-colonies in one-on-one encounters for aggressive responses. We found that workers adjust their nestmate recognition by learning novel, manipulated CHC profiles, but still accept workers with the previous CHC profile. Workers from a sub-colony with two additional components showed aggression against workers with only one of the two components added to their CHC profile. Thus, additional components as well as the lack of a component can alter a label as "non-nestmate." Our results suggest that ants have multiple-templates to recognize nestmates carrying distinct labels. This finding is in contrast to what previously has been proposed, i.e., a widening of the acceptance range of one template. We conclude that nestmate recognition in ants is a partitioned (multiple-template) process of the olfactory system that allows discrimination and categorization of nestmates by differences in their CHC profiles. Our findings have strong implications for our understanding of the underlying mechanisms of colony coherence and task allocation because they illustrate the importance of individual experience and task associated differences in the CHC profiles that can be instructive for the organization of insect societies.}, }
@article {pmid30209226, year = {2018}, author = {Kazem, AJN and Barth, Y and Pfefferle, D and Kulik, L and Widdig, A}, title = {Parent-offspring facial resemblance increases with age in rhesus macaques.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1886}, pages = {}, pmid = {30209226}, issn = {1471-2954}, support = {P40 OD012217/OD/NIH HHS/United States ; }, mesh = {Age Factors ; Animals ; Cues ; *Face ; Female ; Humans ; Macaca mulatta/*physiology ; Male ; *Phenotype ; *Visual Perception ; }, abstract = {Kin recognition is a key ability which facilitates the acquisition of inclusive fitness benefits and enables optimal outbreeding. In primates, phenotype matching is considered particularly important for the recognition of patrilineal relatives, as information on paternity is unlikely to be available via social familiarity. Phenotypic cues to both paternal and maternal relatedness exist in the facial features of humans and other primates. However, theoretical models suggest that in systems with uncertainty parentage it may be adaptive for offspring to conceal such cues when young, in order to avoid potential costs of being discriminated against by unrelated adults. Using experienced human raters, we demonstrate in a computer-based task that detection of parent-offspring resemblances in the faces of rhesus macaques (Macaca mulatta) increases significantly with offspring age. Moreover, this effect is specific to information about kinship, as raters were extremely successful at discriminating individuals even among the youngest animals. To our knowledge, this is the first evidence in non-humans for the age-dependent expression of visual cues used in kin recognition.}, }
@article {pmid30165602, year = {2019}, author = {Bawa, KS and Ingty, T and Revell, LJ and Shivaprakash, KN}, title = {Correlated evolution of flower size and seed number in flowering plants (monocotyledons).}, journal = {Annals of botany}, volume = {123}, number = {1}, pages = {181-190}, pmid = {30165602}, issn = {1095-8290}, mesh = {*Biological Evolution ; Flowers/*anatomy &amp; histology/growth &amp; development ; Magnoliopsida/*anatomy &amp; histology/growth &amp; development/*physiology ; Phylogeny ; Seeds/*physiology ; }, abstract = {BACKGROUND AND AIMS: Kin selection theory predicts that a parent may minimize deleterious effects of competition among seeds developing within ovaries by increasing the genetic relatedness of seeds within an ovary. Alternatively, the number of developing seeds could be reduced to one or a few. It has also been suggested that single or few seeded fruits may be correlated with small flowers, and multi-ovulate ovaries or many seeded fruits may be associated with large flowers with specialized pollination mechanisms. We examined the correlation between flower size and seed number in 69 families of monocotyledons to assess if correlations are significant and independent of phylogeny.<br><br>METHODS: We first examined the effect of phylogenetic history on the evolution of these two traits, flower size and seed number, and then mapped correlations between them on the latest phylogenetic tree of monocotyledons.<br><br>RESULTS: The results provide phylogenetically robust evidence of strong correlated evolution between flower size and seed number and show that correlated evolution of traits is not constrained by phylogenetic history of taxa. Moreover, the two character combinations, small flowers and a single or few seeds per fruit, and large flowers and many seeded fruits, have persisted in monocotyledons longer than other trait combinations.<br><br>CONCLUSIONS: The analyses support the suggestion that most angiosperms may fall into two categories, one with large flowers and many seeded fruits and the other with small flowers and single or few seeded fruits, and kin selection within ovaries may explain the observed patterns.}, }
@article {pmid30135160, year = {2018}, author = {Downing, PA and Griffin, AS and Cornwallis, CK}, title = {Sex differences in helping effort reveal the effect of future reproduction on cooperative behaviour in birds.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1885}, pages = {}, pmid = {30135160}, issn = {1471-2954}, mesh = {Animals ; Birds/*physiology ; Cooperative Behavior ; Female ; Helping Behavior ; Male ; *Nesting Behavior ; *Reproduction ; Sex Characteristics ; }, abstract = {The evolution of helping behaviour in species that breed cooperatively in family groups is typically attributed to kin selection alone. However, in many species, helpers go on to inherit breeding positions in their natal groups, but the extent to which this contributes to selection for helping is unclear as the future reproductive success of helpers is often unknown. To quantify the role of future reproduction in the evolution of helping, we compared the helping effort of female and male retained offspring across cooperative birds. The kin selected benefits of helping are equivalent between female and male helpers-they are equally related to the younger siblings they help raise-but the future reproductive benefits of helping differ because of sex differences in the likelihood of breeding in the natal group. We found that the sex which is more likely to breed in its natal group invests more in helping, suggesting that in addition to kin selection, helping in family groups is shaped by future reproduction.}, }
@article {pmid30108624, year = {2018}, author = {Ren, Y and Huang, K and Guo, S and Pan, R and Derek, DW and Qi, X and Wang, X and Wang, C and Zhao, H and Yang, B and Li, F and Li, B}, title = {Kinship promotes affiliative behaviors in a monkey.}, journal = {Current zoology}, volume = {64}, number = {4}, pages = {441-447}, pmid = {30108624}, issn = {1674-5507}, abstract = {In social mammals, kinship is an important factor that often affects the interactions among individuals within groups. In primates that live in a multilevel society, kinship may affect affiliative patterns between individuals at different scales within the larger group. For this study, we use field observations and molecular methods to reveal the profiles of how kinship affects affiliative behaviors between individuals in a breeding band of wild golden snub-nosed monkeys (Rhinopithecus roxellana). We use a novel nonparametric test, the partition Mantel test, to measure independently the correlation between kinship and each of three affiliative behaviors. Our results show that more closely related females are more likely to groom each other. Average relatedness between adult females within the same one-male unit (OMU) is higher than that between adult females from different OMUs. We suggest that closely related females may reside in the same OMU in order to attain inclusive fitness benefits, and that kinship plays an important role in maintaining the social structure of this species.}, }
@article {pmid30080237, year = {2018}, author = {D'Aloia, CC and Neubert, MG}, title = {The formation of marine kin structure: effects of dispersal, larval cohesion, and variable reproductive success.}, journal = {Ecology}, volume = {99}, number = {10}, pages = {2374-2384}, doi = {10.1002/ecy.2480}, pmid = {30080237}, issn = {0012-9658}, support = {DEB-1558904//US NSF/International ; }, mesh = {Animals ; *Genetics, Population ; Inbreeding ; Larva ; *Reproduction ; }, abstract = {The spatial distribution of relatives has profound effects on kin interactions, inbreeding, and inclusive fitness. Yet, in the marine environment, the processes that generate patterns of kin structure remain understudied because larval dispersal on ocean currents was historically assumed to disrupt kin associations. Recent genetic evidence of co-occurring siblings challenges this assumption and raises the intriguing question of how siblings are found together after a (potentially) disruptive larval phase. Here, we develop individual-based models to explore how stochastic processes operating at the individual level affect expected kinship at equilibrium. Specifically, we predict how limited dispersal, sibling cohesion, and variability in reproductive success differentially affect patterns of kin structure. All three mechanisms increase mean kinship within populations, but their spatial effects are markedly different. We find that (1) when dispersal is limited, kinship declines monotonically as a function of the distance between individuals; (2) when siblings disperse cohesively, kinship increases within a site relative to between sites; and (3) when reproductive success varies, kinship increases equally at all distances. The differential effects of these processes therefore only become apparent when individuals are sampled at multiple spatial scales. Notably, our models suggest that aggregative larval behaviors, such as sibling cohesion, are not necessary to explain documented levels of relatedness within marine populations. Together, these findings establish a theoretical framework for disentangling the drivers of marine kin structure.}, }
@article {pmid30073752, year = {2019}, author = {Andersson, M and Åhlund, M and Waldeck, P}, title = {Brood parasitism, relatedness and sociality: a kinship role in female reproductive tactics.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {94}, number = {1}, pages = {307-327}, doi = {10.1111/brv.12455}, pmid = {30073752}, issn = {1469-185X}, abstract = {Conspecific brood parasitism (CBP) is a reproductive tactic in which parasitic females lay eggs in nests of other females of the same species that then raise the joint brood. Parasites benefit by increased reproduction, without costs of parental care for the parasitic eggs. CBP occurs in many egg-laying animals, among birds most often in species with large clutches and self-feeding young: two major factors facilitating successful parasitism. CBP is particularly common in waterfowl (Anatidae), a group with female-biased natal philopatry and locally related females. Theory suggests that relatedness between host and parasite can lead to inclusive fitness benefits for both, but if host costs are high, parasites should instead target unrelated females. Pairwise relatedness (r) in host-parasite (h-p) pairs of females has been estimated using molecular genetic methods in seven waterfowl (10 studies). In many h-p pairs, the two females were unrelated (with low r, near the local population mean). However, close relatives (r = 0.5) were over-represented in h-p pairs, which in all 10 studies had higher mean relatedness than other females. In one species where this was studied, h-p relatedness was higher than between nesting close neighbours, and hosts parasitized by non-relatives aggressively rejected other females. In another species, birth nest-mates (mother-daughters, sisters) associated in the breeding area as adults, and became h-p pairs more often than expected by chance. These and other results point to recognition of birth nest-mates and perhaps other close relatives. For small to medium host clutch sizes, addition of a few parasitic eggs need not reduce host offspring success. Estimates in two species suggest that hosts can then gain inclusive fitness if parasitized by relatives. Other evidence of female cooperation is incubation by old eider Somateria mollissima females of clutches laid by their relatives, and merging and joint care of broods of young. Merging females tended to be more closely related. Eiders associate with kin in many situations, and in some geese and swans, related females may associate over many years. Recent genetic evidence shows that also New World quails (Odontophoridae) have female-biased natal philopatry, CBP and brood merging, inviting further study and comparison with waterfowl. Kin-related parasitism also occurs in some insects, with revealing parallels and differences compared to birds. In hemipteran bugs, receiving extra eggs is beneficial for hosts by diluting offspring predation. In eggplant lace bugs Gargaphia solani, host and parasite are closely related, and kin selection favours egg donation to related females. Further studies of kinship in CBP, brood merging and other contexts can test if some of these species are socially more advanced than presently known.}, }
@article {pmid30059691, year = {2018}, author = {Gleichsner, AM and Reinhart, K and Minchella, DJ}, title = {Of mice and worms: are co-infections with unrelated parasite strains more damaging to definitive hosts?.}, journal = {International journal for parasitology}, volume = {48}, number = {11}, pages = {881-885}, doi = {10.1016/j.ijpara.2018.05.004}, pmid = {30059691}, issn = {1879-0135}, mesh = {Animals ; Biomphalaria/*parasitology ; *Coinfection ; Host-Parasite Interactions ; Humans ; Mice ; Schistosoma mansoni/*classification/genetics/pathogenicity/physiology ; Schistosomiasis mansoni/*parasitology ; Virulence ; }, abstract = {Intraspecific competition between co-infecting parasites can influence the amount of virulence, or damage, they do to their host. Kin selection theory dictates that infections with related parasite individuals should have lower virulence than infections with unrelated individuals, because they benefit from inclusive fitness and increased host longevity. These predictions have been tested in a variety of microparasite systems, and in larval stage macroparasites within intermediate hosts, but the influence of adult macroparasite relatedness on virulence has not been investigated in definitive hosts. This study used the human parasite Schistosoma mansoni to determine whether definitive hosts infected with related parasites experience lower virulence than hosts infected with unrelated parasites, and to compare the results from intermediate host studies in this system. The presence of unrelated parasites in an infection decreased parasite infectivity, the ability of a parasite to infect a definitive host, and total worm establishment in hosts, impacting the less virulent parasite strain more severely. Unrelated parasite co-infections had similar virulence to the more virulent of the two parasite strains. We combine these findings with complementary studies of the intermediate snail host and describe trade-offs in virulence and selection within the life cycle. Damage to the host by the dominant strain was muted by the presence of a competitor in the intermediate host, but was largely unaffected in the definitive host. Our results in this host-parasite system suggest that unrelated infections may select for higher virulence in definitive hosts while selecting for lower virulence in intermediate hosts.}, }
@article {pmid30055104, year = {2019}, author = {Espinosa, A and Paz-Y-Miño-C, G}, title = {Discrimination Experiments in Entamoeba and Evidence from Other Protists Suggest Pathogenic Amebas Cooperate with Kin to Colonize Hosts and Deter Rivals.}, journal = {The Journal of eukaryotic microbiology}, volume = {66}, number = {2}, pages = {354-368}, pmid = {30055104}, issn = {1550-7408}, support = {P20 GM103430/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Biological Evolution ; Entamoeba/*physiology ; Entamoebiasis/parasitology ; *Microbial Interactions ; Species Specificity ; }, abstract = {Entamoeba histolytica is one of the least understood protists in terms of taxa, clone, and kin discrimination/recognition ability. However, the capacity to tell apart same or self (clone/kin) from different or nonself (nonclone/nonkin) has long been demonstrated in pathogenic eukaryotes like Trypanosoma and Plasmodium, free-living social amebas (Dictyostelium, Polysphondylium), budding yeast (Saccharomyces), and in numerous bacteria and archaea (prokaryotes). Kin discrimination/recognition is explained under inclusive fitness theory; that is, the reproductive advantage that genetically closely related organisms (kin) can gain by cooperating preferably with one another (rather than with distantly related or unrelated individuals), minimizing antagonism and competition with kin, and excluding genetic strangers (or cheaters = noncooperators that benefit from others' investments in altruistic cooperation). In this review, we rely on the outcomes of in vitro pairwise discrimination/recognition encounters between seven Entamoeba lineages to discuss the biological significance of taxa, clone, and kin discrimination/recognition in a range of generalist and specialist species (close or distantly related phylogenetically). We then focus our discussion on the importance of these laboratory observations for E. histolytica's life cycle, host infestation, and implications of these features of the amebas' natural history for human health (including mitigation of amebiasis).}, }
@article {pmid29998471, year = {2019}, author = {Minorsky, PV}, title = {The functions of foliar nyctinasty: a review and hypothesis.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {94}, number = {1}, pages = {216-229}, pmid = {29998471}, issn = {1469-185X}, abstract = {Foliar nyctinasty is a plant behaviour characterised by a pronounced daily oscillation in leaf orientation. During the day, the blades of nyctinastic plant leaves (or leaflets) assume a more or less horizontal position that optimises their ability to capture sunlight for photosynthesis. At night, the positions that the leaf blades assume, regardless of whether they arise by rising, falling or twisting, are essentially vertical. Among the ideas put forth to explain the raison d'être of foliar nyctinasty are that it: (i) improves the temperature relations of plants; (ii) helps remove surface water from foliage; (iii) prevents the disruption of photoperiodism by moonlight; and (iv) directly discourages insect herbivory. After discussing these previous hypotheses, a novel tritrophic hypothesis is introduced that proposes that foliar nyctinasty constitutes an indirect plant defence against nocturnal herbivores. It is suggested that the reduction in physical clutter that follows from nocturnal leaf closure may increase the foraging success of many types of animals that prey upon or parasitise herbivores. Predators and parasitoids generally use some combination of visual, auditory or olfactory cues to detect prey. In terrestrial environments, it is hypothesised that the vertical orientation of the blades of nyctinastic plants at night would be especially beneficial to flying nocturnal predators (e.g. bats and owls) and parasitoids whose modus operandi is death from above. The movements of prey beneath a plant with vertically oriented foliage would be visually more obvious to gleaning or swooping predators under nocturnal or crepuscular conditions. Such predators could also detect sounds made by prey better without baffling layers of foliage overhead to damp and disperse the signal. Moreover, any volatiles released by the prey would diffuse more directly to the awaiting olfactory apparatus of the predators or parasitoids. In addition to facilitating the demise of herbivores by carnivores and parasitoids, foliar nyctinasty, much like the enhanced illumination of the full moon, may mitigate feeding by nocturnal herbivores by altering their foraging behaviour. Foliar nyctinasty could also provide a competitive advantage by encouraging herbivores, seeking more cover, to forage on or around non-nyctinastic species. As an added advantage, foliar nyctinasty, by decreasing the temperature between plants through its effects on re-radiation, may slow certain types of ectothermic herbivores making them more vulnerable to predation. Foliar nyctinasty also may not solely be a behavioural adaptation against folivores; by discouraging foraging by granivores, the inclusive fitness of nyctinastic plants may be increased.}, }
@article {pmid29943825, year = {2018}, author = {Bovet, J and Raiber, E and Ren, W and Wang, C and Seabright, P}, title = {Parent-offspring conflict over mate choice: An experimental study in China.}, journal = {British journal of psychology (London, England : 1953)}, volume = {109}, number = {4}, pages = {674-693}, doi = {10.1111/bjop.12319}, pmid = {29943825}, issn = {2044-8295}, support = {71540032//National Natural Science Foundation of China/ ; //ANR - Labex IAST/ ; }, mesh = {Adult ; China ; *Family Conflict ; Female ; Humans ; Male ; Marriage/*psychology ; *Parent-Child Relations ; Parents ; Young Adult ; }, abstract = {Both parents and offspring have evolved mating preferences that enable them to select mates and children-in-law to maximize their inclusive fitness. The theory of parent-offspring conflict predicts that preferences for potential mates may differ between parents and offspring: individuals are expected to value biological quality more in their own mates than in their offspring's mates and to value investment potential more in their offspring's mates than in their own mates. We tested this hypothesis in China using a naturalistic 'marriage market' where parents actively search for marital partners for their offspring. Parents gather at a public park to advertise the characteristics of their adult children, looking for a potential son or daughter-in-law. We presented 589 parents and young adults from the city of Kunming (Yunnan, China) with hypothetical mating candidates varying in their levels of income (proxy for investment potential) and physical attractiveness (proxy for biological quality). We found some evidence of a parent-offspring conflict over mate choice, but only in the case of daughters, who evaluated physical attractiveness as more important than parents. We also found an effect of the mating candidate's sex, as physical attractiveness was deemed more valuable in a female potential mate by parents and offspring alike.}, }
@article {pmid29924339, year = {2018}, author = {Piekarski, PK and Carpenter, JM and Lemmon, AR and Moriarty Lemmon, E and Sharanowski, BJ}, title = {Phylogenomic Evidence Overturns Current Conceptions of Social Evolution in Wasps (Vespidae).}, journal = {Molecular biology and evolution}, volume = {35}, number = {9}, pages = {2097-2109}, pmid = {29924339}, issn = {1537-1719}, mesh = {Animals ; *Biological Evolution ; Female ; Nesting Behavior ; *Social Behavior ; Wasps/*genetics ; }, abstract = {The hypothesis that eusociality originated once in Vespidae has shaped interpretation of social evolution for decades and has driven the supposition that preimaginal morphophysiological differences between castes were absent at the outset of eusociality. Many researchers also consider casteless nest-sharing an antecedent to eusociality. Together, these ideas endorse a stepwise progression of social evolution in wasps (solitary → casteless nest-sharing → eusociality with rudimentary behavioral castes → eusociality with preimaginal caste-biasing (PCB) → morphologically differentiated castes). Here, we infer the phylogeny of Vespidae using sequence data generated via anchored hybrid enrichment from 378 loci across 136 vespid species and perform ancestral state reconstructions to test whether rudimentary and monomorphic castes characterized the initial stages of eusocial evolution. Our results reject the single origin of eusociality hypothesis, contest the supposition that eusociality emerged from a casteless nest-sharing ancestor, and suggest that eusociality in Polistinae + Vespinae began with castes having morphological differences. An abrupt appearance of castes with ontogenetically established morphophysiological differences conflicts with the current conception of stepwise social evolution and suggests that the climb up the ladder of sociality does not occur through sequential mutation. Phenotypic plasticity and standing genetic variation could explain how cooperative brood care evolved in concert with nest-sharing and how morphologically dissimilar castes arose without a rudimentary intermediate. Furthermore, PCB at the outset of eusociality implicates a subsocial route to eusociality in Polistinae + Vespinae, emphasizing the role of mother-daughter interactions and subfertility (i.e. the cost component of kin selection) in the origin of workers.}, }
@article {pmid29904961, year = {2018}, author = {Rodrigues, AMM}, title = {Demography, life history and the evolution of age-dependent social behaviour.}, journal = {Journal of evolutionary biology}, volume = {31}, number = {9}, pages = {1340-1353}, doi = {10.1111/jeb.13308}, pmid = {29904961}, issn = {1420-9101}, mesh = {*Aging ; Biological Evolution ; *Cooperative Behavior ; Fertility ; *Models, Biological ; Phenotype ; *Social Behavior ; }, abstract = {Since the inception of modern social evolution theory, a vast majority of studies have sought to explain cooperation using relatedness-driven hypotheses. Natural populations, however, show a substantial amount of variation in social behaviour that is uncorrelated with relatedness. Age offers a major alternative explanation for variation in behaviour that remains unaccounted for. Most natural populations are structured into age-classes, with ageing being a nearly universal feature of most major taxa, including eukaryotic and prokaryotic organisms. Despite this, the theoretical underpinnings of age-dependent social behaviour remain limited. Here, I investigate how group age-composition, demography and life history shape trajectories of age-dependent behaviours that are expressed conditionally on an actor and recipient's age. I show that demography introduces novel age-dependent selective pressures acting on social phenotypes. Furthermore, I find that life history traits influence the costs and benefits of cooperation directly, but also indirectly. Life history has a strong impact not only on the genetic structure of the population but also on the distribution of group age-compositions, with both of these processes influencing the expression of age-dependent cooperation. Age of peak reproductive performance, in particular, is of chief importance for the evolution of cooperation, as this will largely determine the age and relatedness of social partners. Moreover, my results suggest that later-life reproductive senescence may occur because of demographic effects alone, which opens new vistas on the evolution of menopause and related phenomena.}, }
@article {pmid29892408, year = {2018}, author = {Davies, NG and Gardner, A}, title = {Monogamy promotes altruistic sterility in insect societies.}, journal = {Royal Society open science}, volume = {5}, number = {5}, pages = {172190}, pmid = {29892408}, issn = {2054-5703}, abstract = {Monogamy is associated with sibling-directed altruism in multiple animal taxa, including insects, birds and mammals. Inclusive-fitness theory readily explains this pattern by identifying high relatedness as a promoter of altruism. In keeping with this prediction, monogamy should promote the evolution of voluntary sterility in insect societies if sterile workers make for better helpers. However, a recent mathematical population-genetics analysis failed to identify a consistent effect of monogamy on voluntary worker sterility. Here, we revisit that analysis. First, we relax genetic assumptions, considering not only alleles of extreme effect-encoding either no sterility or complete sterility-but also alleles with intermediate effects on worker sterility. Second, we broaden the stability analysis-which focused on the invasibility of populations where either all workers are fully sterile or all workers are fully reproductive-to identify where intermediate pure or mixed evolutionarily stable states may occur. Third, we consider a broader range of demographically explicit ecological scenarios relevant to altruistic worker non-reproduction and to the evolution of eusociality more generally. We find that, in the absence of genetic constraints, monogamy always promotes altruistic worker sterility and may inhibit spiteful worker sterility. Our extended analysis demonstrates that an exact population-genetics approach strongly supports the prediction of inclusive-fitness theory that monogamy promotes sib-directed altruism in social insects.}, }
@article {pmid29848655, year = {2018}, author = {Dos Santos, M and West, SA}, title = {The coevolution of cooperation and cognition in humans.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1879}, pages = {}, pmid = {29848655}, issn = {1471-2954}, mesh = {*Biological Evolution ; *Cognition ; *Cooperative Behavior ; Humans ; Models, Biological ; }, abstract = {Cooperative behaviours in archaic hunter-gatherers could have been maintained partly due to the gains from cooperation being shared with kin. However, the question arises as to how cooperation was maintained after early humans transitioned to larger groups of unrelated individuals. We hypothesize that after cooperation had evolved via benefits to kin, the consecutive evolution of cognition increased the returns from cooperating, to the point where benefits to self were sufficient for cooperation to remain stable when group size increased and relatedness decreased. We investigate the theoretical plausibility of this hypothesis, with both analytical modelling and simulations. We examine situations where cognition either (i) increases the benefits of cooperation, (ii) leads to synergistic benefits between cognitively enhanced cooperators, (iii) allows the exploitation of less intelligent partners, and (iv) the combination of these effects. We find that cooperation and cognition can coevolve-cooperation initially evolves, favouring enhanced cognition, which favours enhanced cooperation, and stabilizes cooperation against a drop in relatedness. These results suggest that enhanced cognition could have transformed the nature of cooperative dilemmas faced by early humans, thereby explaining the maintenance of cooperation between unrelated partners.}, }
@article {pmid29802804, year = {2018}, author = {Wade, MJ and Fitzpatrick, CL and Lively, CM}, title = {50-year anniversary of Lloyd's "mean crowding": Ideas on patchy distributions.}, journal = {The Journal of animal ecology}, volume = {87}, number = {5}, pages = {1221-1226}, pmid = {29802804}, issn = {1365-2656}, support = {T32 HD049336/HD/NICHD NIH HHS/United States ; }, mesh = {Animals ; *Anniversaries and Special Events ; *Biological Evolution ; }, abstract = {This year marks the 50th anniversary of Monte B. Lloyd's "Mean Crowding" (1967) paper, in which he introduced a metric that accounts for an individual's experience of conspecific density. Mean crowding allows ecologists to measure the degree of spatial aggregation of individuals in a manner relevant to intraspecific competition for resources. We take the concept of mean crowding a step beyond its most common usage and that it has a mathematical relationship to many of the most important concepts in ecology and evolutionary biology. Mean crowding, a first-order approximation of the degree of nonrandomness in a distribution, can function as a powerful heuristic that can unify concepts across disciplines in a more general way that Lloyd originally envisioned.}, }
@article {pmid29797146, year = {2018}, author = {Nila, S and Barthes, J and Crochet, PA and Suryobroto, B and Raymond, M}, title = {Kin Selection and Male Homosexual Preference in Indonesia.}, journal = {Archives of sexual behavior}, volume = {47}, number = {8}, pages = {2455-2465}, doi = {10.1007/s10508-018-1202-y}, pmid = {29797146}, issn = {1573-2800}, mesh = {Biological Evolution ; Family/*psychology ; Female ; Homosexuality, Male/*psychology ; Humans ; Indonesia ; Male ; *Reproduction ; *Selection, Genetic ; Sexual Behavior ; Sexual and Gender Minorities/psychology/*statistics &amp; numerical data ; }, abstract = {Male homosexual preference (MHP) challenges evolutionary thinking because the preference for male-male relationships is heritable, implies a fertility cost (lower offspring number), and is relatively frequent in some societies (2-6% in Western countries) for a costly trait. It has been proposed that individuals with a MHP counterbalance reproductive costs through the transfer of resources to kin, thereby improving their indirect reproduction through kin's reproductive success. This kin selection hypothesis is not supported in Western countries and Japan, although consistent evidence has been obtained in Samoa. In this study, data from Java (Indonesia) were obtained to assess the avuncular tendencies of men with contrasting sexual orientation to measure possible resource transfer. Consistent with the kin selection hypothesis, males with a homosexual orientation reported an increased willingness to transfer resources toward nephews and nieces and declared having transferred more money to nephews and nieces. We developed a method to quantitatively estimate the contribution of kin selection on inclusive reproduction associated to sexual orientation, taking into account various possible biases. Kin selection reduced the direct reproductive cost of homosexual men by 20%, so suggesting that kin selection alone is insufficient to explain the maintenance of male homosexuality. Other potential factors are discussed, as well as the limitations of the study and the social determinant operating for the expression of increased avuncular tendencies of homosexual men.}, }
@article {pmid29792446, year = {2019}, author = {Lang, SF and Fowers, BJ}, title = {An expanded theory of Alzheimer's caregiving.}, journal = {The American psychologist}, volume = {74}, number = {2}, pages = {194-206}, doi = {10.1037/amp0000323}, pmid = {29792446}, issn = {1935-990X}, mesh = {Alzheimer Disease/*nursing/*psychology ; Caregivers/*psychology ; Humans ; }, abstract = {The ancient and cross-culturally prevalent pattern of caregiving suggests that long-term caregiving is species characteristic for humans. If so, then an evolutionary account of the adaptation(s) that underwrite this caregiving is necessary, particularly for the one-sided and long-term nature of Alzheimer's caregiving. Four standard evolutionary explanations are evaluated: kin selection theory, the grandmother hypothesis, direct reciprocity, and indirect reciprocity. Each is found inadequate to explain caregiving because of the lack of reproductive benefits. These evolutionary accounts also assume that relationships are only valuable to the degree that they provide benefits and that relationship partners are predominantly motivated by self-interest. Attachment provides another explanation, which evolved initially to ensure infant protection and nurturance, but was exapted for important adult relationships. Attachment relationships naturally include caregiving and engender long-term relational commitment. Yet attachment theory is ambiguous about whether relationships are maintained for the sake of security benefits or because they have inherent value. This ambiguity undermines the explanatory value of attachment theory for Alzheimer's caregiving. Therefore, a shared identity theory is offered that highlights the inherent value of the relationship and the loved one, transcending the predominant focus on beneficial individual outcomes. The theory emphasizes the frequent human motivation to benefit others because of their mutual commitment, shared identity, and shared goals. The conclusion is that fully understanding and supporting the arduous efforts of caregiving for loved ones with Alzheimer's requires psychologists to fully appreciate and support the deep and meaningful motivations that often inspire the humanity seen in caregiving. (PsycINFO Database Record (c) 2019 APA, all rights reserved).}, }
@article {pmid29765670, year = {2018}, author = {Koster, J}, title = {Family ties: the multilevel effects of households and kinship on the networks of individuals.}, journal = {Royal Society open science}, volume = {5}, number = {4}, pages = {172159}, pmid = {29765670}, issn = {2054-5703}, abstract = {Among social mammals, humans uniquely organize themselves into communities of households that are centred around enduring, predominantly monogamous unions of men and women. As a consequence of this social organization, individuals maintain social relationships both within and across households, and potentially there is conflict among household members about which social ties to prioritize or de-emphasize. Extending the logic of structural balance theory, I predict that there will be considerable overlap in the social networks of individual household members, resulting in a pattern of group-level reciprocity. To test this prediction, I advance the Group-Structured Social Relations Model, a generalized linear mixed model that tests for group-level effects in the inter-household social networks of individuals. The empirical data stem from social support interviews conducted in a community of indigenous Nicaraguan horticulturalists, and model results show high group-level reciprocity among households. Although support networks are organized around kinship, covariates that test predictions of kin selection models do not receive strong support, potentially because most kin-directed altruism occurs within households, not between households. In addition, the models show that households with high genetic relatedness in part from children born to adulterous relationships are less likely to assist each other.}, }
@article {pmid29756687, year = {2018}, author = {Jänig, S and Weiß, BM and Widdig, A}, title = {Comparing the sniffing behavior of great apes.}, journal = {American journal of primatology}, volume = {80}, number = {6}, pages = {e22872}, doi = {10.1002/ajp.22872}, pmid = {29756687}, issn = {1098-2345}, mesh = {Age Factors ; Animals ; Behavior, Animal/physiology ; Female ; Food ; Gorilla gorilla/*physiology ; Male ; Pan paniscus/*physiology ; Pan troglodytes/*physiology ; Pongo abelii/*physiology ; Sex Factors ; Smell/*physiology ; Social Behavior ; }, abstract = {The importance of smell in humans is well established but we know little about it in regard to our closest relatives, the great apes, as systematic studies on their olfactory behavior are still lacking. Olfaction has long been considered to be of lesser importance in hominids given their relatively smaller olfactory bulbs, fewer functional olfactory receptor genes than other species and absence of a functional vomeronasal organ. Therefore, the aim of this study was to evaluate the use of olfaction in hominids. In particular, we observed sniffing behavior in captive groups of four species (Sumatran orangutans, Pongo abelii; Western lowland gorillas, Gorilla gorilla gorilla; Western chimpanzees, Pan troglodytes verus; bonobos, Pan paniscus) and evaluated in which contexts sniffing was used. Our results show that all investigated species frequently used the sense of smell, and that the sniffing frequency varied with species, sex, age, and context. Most sniffing events were observed in gorillas in comparison to the three other species. Sniffing frequencies were also influenced by sex, with males sniffing slightly more often than females. Furthermore, our results revealed an effect of age, with younger individuals sniffing more often than older individuals. All species mainly sniffed in the non-social context (i.e., toward food and other environmental items) rather than in the social context (i.e., at conspecifics), suggesting that the evaluation of the environment and the nutritional value of food items is of major importance to all great ape species investigated here. In contrast to the other species and female chimpanzees, however, male chimpanzees most often used olfaction to inspect their conspecifics. Together, our study suggests that olfaction is likely to be more important in great apes than previously appreciated.}, }
@article {pmid29753459, year = {2018}, author = {Boose, K and White, F and Brand, C and Meinelt, A and Snodgrass, J}, title = {Infant handling in bonobos (Pan paniscus): Exploring functional hypotheses and the relationship to oxytocin.}, journal = {Physiology &amp; behavior}, volume = {193}, number = {Pt A}, pages = {154-166}, doi = {10.1016/j.physbeh.2018.04.012}, pmid = {29753459}, issn = {1873-507X}, mesh = {Animals ; Behavior, Animal/*physiology ; Female ; Humans ; Learning/physiology ; Male ; Maternal Behavior/*physiology/psychology ; Models, Biological ; Oxytocin/*urine ; Pan paniscus/*metabolism/psychology ; Paternal Behavior/physiology/psychology ; *Social Behavior ; }, abstract = {Infant handling describes interactions between infants and non-maternal group members and is widespread across mammalian taxa. The expression of infant handling behaviors, defined as any affiliative or agonistic interaction between a group member and an infant, varies considerably among primate species. Several functional hypotheses may explain the adaptive value of infant handling including the Kin Selection hypothesis, which describes handling as a mechanism through which indirect fitness is increased and predicts a bias in handling behaviors directed toward related (genetic) infants; the Alliance Formation hypothesis, which describes handling as a social commodity and predicts females with infants will support handlers during conflict; and the Learning-to-Mother hypothesis, which describes handling as a mechanism through which handlers learn species-specific maternal behaviors and predicts that handling will occur most frequently in immature and nulliparous females. Using behavioral observation and data on urinary oxytocin, a neuropeptide hormone known to modulate maternal care and social bonds in mammals, the purpose of this study was to describe the pattern of infant handling in bonobos (Pan paniscus) and to explore proposed functional hypotheses. Data show that related infant-handler dyads occurred significantly more frequently than unrelated infant-handler dyads during some of the study period and that handling was positively correlated with support during conflict. Data also showed that immature and nulliparous females handled infants significantly more than other age-sex categories and exhibited higher post handling oxytocin values than other age-sex class. The trends identified in this data set provide insight into the role oxytocin may play in facilitating care-giving behaviors in young female bonobos and help to narrow the focus of future research efforts, particularly those associated with the Kin Selection, Alliance Formation, and Learning-to-Mother functional hypotheses.}, }
@article {pmid29745213, year = {2017}, author = {Lai, BM and Wang, MZ and Shen, DS}, title = {[Bacterial quorum sensing: Cooperation and cheating].}, journal = {Ying yong sheng tai xue bao = The journal of applied ecology}, volume = {28}, number = {5}, pages = {1735-1742}, doi = {10.13287/j.1001-9332.201705.018}, pmid = {29745213}, issn = {1001-9332}, mesh = {*Bacteria ; Biofilms ; Ecological and Environmental Phenomena ; *Quorum Sensing ; }, abstract = {Quorum sensing (QS), a cell-to-cell communication, regulates a variety of social beha-viors, such as biofilm formation, public goods produce and gene horizontal transfer of bacteria. In the process of quorum sensing, public goods could be utilized by any members in the population, which was termed as cooperation. Notably, public goods also could be shared by the individuals who could not produce them, which was termed as cheating. Once cheaters come up, they possibly maintain equilibrium with cooperators, meanwhile they also possibly induce the collapse of population due to their rapid growth and shortage of public goods. Therefore, invasion of cheaters arouses wide attentions in medicine, agriculture, food science and so on regarded as a new strategy to control pathogens. In this study, based on the introduction about the theory of bacterial quorum sensing cooperation and cheating, we analyzed the factors influencing the formation and development of the relationship between cooperator and cheater. Moreover, we discussed the mechanism of stabilization in the relationship between cooperator and cheater, including kin selection, metabolic prudence, metabolic constraint (gene pleiotropy) and policing quorum sensing. Finally, some problems in current researches of quorum sensing cooperation and cheating were presented as well as the future research directions. We hoped this paper could deepen the understanding of bacterial quorum sen-sing and ecology of bacterial population.}, }
@article {pmid29735672, year = {2018}, author = {Madgwick, PG and Stewart, B and Belcher, LJ and Thompson, CRL and Wolf, JB}, title = {Strategic investment explains patterns of cooperation and cheating in a microbe.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {21}, pages = {E4823-E4832}, pmid = {29735672}, issn = {1091-6490}, support = {//Wellcome Trust/United Kingdom ; BB/M01035X/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/M007146/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; WT095643AIA//Wellcome Trust/United Kingdom ; }, mesh = {*Biological Evolution ; *Cooperative Behavior ; Dictyostelium/*physiology ; *Game Theory ; Individuality ; *Models, Biological ; Spores, Protozoan/*physiology ; }, abstract = {Contributing to cooperation is typically costly, while its rewards are often available to all members of a social group. So why should individuals be willing to pay these costs, especially if they could cheat by exploiting the investments of others? Kin selection theory broadly predicts that individuals should invest more into cooperation if their relatedness to group members is high (assuming they can discriminate kin from nonkin). To better understand how relatedness affects cooperation, we derived the ‟Collective Investment" game, which provides quantitative predictions for patterns of strategic investment depending on the level of relatedness. We then tested these predictions by experimentally manipulating relatedness (genotype frequencies) in mixed cooperative aggregations of the social amoeba Dictyostelium discoideum, which builds a stalk to facilitate spore dispersal. Measurements of stalk investment by natural strains correspond to the predicted patterns of relatedness-dependent strategic investment, wherein investment by a strain increases with its relatedness to the group. Furthermore, if overall group relatedness is relatively low (i.e., no strain is at high frequency in a group) strains face a scenario akin to the "Prisoner's Dilemma" and suffer from insufficient collective investment. We find that strains employ relatedness-dependent segregation to avoid these pernicious conditions. These findings demonstrate that simple organisms like D. discoideum are not restricted to being ‟cheaters" or ‟cooperators" but instead measure their relatedness to their group and strategically modulate their investment into cooperation accordingly. Consequently, all individuals will sometimes appear to cooperate and sometimes cheat due to the dynamics of strategic investing.}, }
@article {pmid29734799, year = {2018}, author = {Peters, K and Worrich, A and Weinhold, A and Alka, O and Balcke, G and Birkemeyer, C and Bruelheide, H and Calf, OW and Dietz, S and Dührkop, K and Gaquerel, E and Heinig, U and Kücklich, M and Macel, M and Müller, C and Poeschl, Y and Pohnert, G and Ristok, C and Rodríguez, VM and Ruttkies, C and Schuman, M and Schweiger, R and Shahaf, N and Steinbeck, C and Tortosa, M and Treutler, H and Ueberschaar, N and Velasco, P and Weiß, BM and Widdig, A and Neumann, S and Dam, NMV}, title = {Current Challenges in Plant Eco-Metabolomics.}, journal = {International journal of molecular sciences}, volume = {19}, number = {5}, pages = {}, pmid = {29734799}, issn = {1422-0067}, mesh = {*Ecology ; Metabolomics/*trends ; Plants/*genetics/metabolism ; }, abstract = {The relatively new research discipline of Eco-Metabolomics is the application of metabolomics techniques to ecology with the aim to characterise biochemical interactions of organisms across different spatial and temporal scales. Metabolomics is an untargeted biochemical approach to measure many thousands of metabolites in different species, including plants and animals. Changes in metabolite concentrations can provide mechanistic evidence for biochemical processes that are relevant at ecological scales. These include physiological, phenotypic and morphological responses of plants and communities to environmental changes and also interactions with other organisms. Traditionally, research in biochemistry and ecology comes from two different directions and is performed at distinct spatiotemporal scales. Biochemical studies most often focus on intrinsic processes in individuals at physiological and cellular scales. Generally, they take a bottom-up approach scaling up cellular processes from spatiotemporally fine to coarser scales. Ecological studies usually focus on extrinsic processes acting upon organisms at population and community scales and typically study top-down and bottom-up processes in combination. Eco-Metabolomics is a transdisciplinary research discipline that links biochemistry and ecology and connects the distinct spatiotemporal scales. In this review, we focus on approaches to study chemical and biochemical interactions of plants at various ecological levels, mainly plant[-]organismal interactions, and discuss related examples from other domains. We present recent developments and highlight advancements in Eco-Metabolomics over the last decade from various angles. We further address the five key challenges: (1) complex experimental designs and large variation of metabolite profiles; (2) feature extraction; (3) metabolite identification; (4) statistical analyses; and (5) bioinformatics software tools and workflows. The presented solutions to these challenges will advance connecting the distinct spatiotemporal scales and bridging biochemistry and ecology.}, }
@article {pmid29728393, year = {2018}, author = {Bruger, EL and Waters, CM}, title = {Maximizing Growth Yield and Dispersal via Quorum Sensing Promotes Cooperation in Vibrio Bacteria.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {14}, pages = {}, pmid = {29728393}, issn = {1098-5336}, support = {R01 GM109259/GM/NIGMS NIH HHS/United States ; R01 GM110444/GM/NIGMS NIH HHS/United States ; R03 AI130554/AI/NIAID NIH HHS/United States ; }, mesh = {Culture Media/chemistry ; Evolution, Molecular ; Genotype ; *Models, Biological ; *Quorum Sensing ; Vibrio/*physiology ; }, abstract = {Quorum sensing (QS) is a form of bacterial chemical communication that regulates cellular phenotypes, including certain cooperative behaviors, in response to environmental and demographic changes. Despite the existence of proposed mechanisms that stabilize QS against defector exploitation, it is unclear if or how QS cooperators can proliferate in some model systems in populations mostly consisting of defectors. We predicted that growth in fragmented subpopulations could allow QS cooperators to invade a QS defector population. This could occur despite cooperators having lower relative fitnesses than defectors due to favored weighting of genotypes that produce larger populations of bacteria. Mixed metapopulations of Vibrio QS-proficient or unconditional cooperators and QS defectors were diluted and fragmented into isolated subpopulations in an environment that requires QS-regulated public good production to achieve larger population yields. Under these conditions, we observed global invasions of both cooperator genotypes into populations composed of primarily defectors. This spatially dependent increase in cooperator frequency was replicated for QS cooperators when mixed populations were competed in soft agar motility plates under conditions that allowed cooperators to disperse and outcompete defectors at the population edge, despite being less motile in isolation than defectors. These competition results show that the coordinated growth and dispersal of QS cooperators to additional resources is heavily favored in comparison to unconditional cooperation, and that dispersal of cooperators by motility into new environments, examined here in laboratory populations, constitutes a key mechanism for maintaining QS-regulated cooperation in the face of defection.IMPORTANCE Behaviors that are cooperative in nature are at risk of exploitation by cheating and are thus difficult to maintain by natural selection alone. While bacterial cell-cell communication, known as quorum sensing (QS), can stabilize microbial cooperative behaviors and is widespread in Vibrio species, it is unclear how QS can increase the frequency of cooperative strains in the presence of defectors without additional mechanisms. In this study, we demonstrate under multiple conditions that QS-mediated cooperation can increase in populations of Vibrio strains when cells experience narrow population bottlenecks or disperse from defectors. This occurred for both conditional cooperation mediated by QS and for unconditional cooperation, although conditional cooperators were better able to stabilize cooperation over a much wider range of conditions. Thus, we observed that population structuring allowed for assortment of competing genotypes and promoted cooperation via kin selection in microbes in a QS-dependent manner.}, }
@article {pmid29717496, year = {2018}, author = {Cords, M and Minich, T and Roberts, SJ and Sleator, C}, title = {Evidence for paternal kin bias in the social affiliation of adult female blue monkeys.}, journal = {American journal of primatology}, volume = {80}, number = {5}, pages = {e22761}, doi = {10.1002/ajp.22761}, pmid = {29717496}, issn = {1098-2345}, mesh = {Animals ; *Behavior, Animal ; Cercopithecidae/*physiology ; Family ; Female ; Grooming ; Male ; *Social Behavior ; }, abstract = {If animals increase inclusive fitness by cooperating with relatives, nepotism should involve maternal and paternal kin equally, all else being equal. Evidence of a behavioral bias toward paternal half-siblings in primates is both limited and mixed, with most positive reports from papionins. To expand knowledge of paternal kin recognition, particularly in cercopithecine monkeys, we examined evidence for paternal kin bias in wild blue monkeys (Cercopithecus mitis), a species living mostly in one-male groups. Seasonal breeding and the amount of male reproductive skew in blue monkeys suggests that opportunities to distinguish paternal kin are plentiful, and their social system would make such discrimination beneficial. We compared spatial association and social contact (grooming and contact-sitting) of 20 adult females with at least one paternal half-sibling and at least one non-relative that were present at the same time. We used two data sets, one in which social partners were other parous females, the other in which they were juveniles. Data came from a 7-year period. When interacting with other adult females, subjects groomed and sat in contact with paternal half-siblings significantly more than with known non-kin, and there was a similar trend for spatial association. We detected no paternal kin bias in interactions with juvenile partners. Kin-biased affiliative contact with adult female partners did not appear to be based on age proximity, measured by birth cohort. The study species' social system suggests phenotype matching as the most likely alternative mechanism, though we could not test it directly. Across both behaviors, there was no significant relationship between the number of matrilineal kin a subject had and the degree to which she preferred paternal half-siblings over non-kin as affiliative partners. These findings contribute to a comparative understanding of paternal kin recognition in primates.}, }
@article {pmid29679501, year = {2018}, author = {Rodrigues, AMM and Taylor, TB}, title = {Ecological and demographic correlates of cooperation from individual to budding dispersal.}, journal = {Journal of evolutionary biology}, volume = {31}, number = {7}, pages = {1058-1070}, doi = {10.1111/jeb.13286}, pmid = {29679501}, issn = {1420-9101}, mesh = {*Animal Distribution ; Animal Migration ; Animals ; *Biological Evolution ; Computer Simulation ; *Cooperative Behavior ; *Models, Biological ; Population Dynamics ; }, abstract = {Identifying the ecological and demographic factors that promote the evolution of cooperation is a major challenge for evolutionary biologists. Explanations for the adaptive evolution of cooperation seek to determine which factors make reproduction in cooperative groups more favourable than independent breeding or other selfish strategies. A vast majority of the hypotheses posit that cooperative groups emerge in the context of philopatry, high costs of dispersal, high population density and environmental stability. This route to cooperation, however, fails to explain a growing body of empirical evidence in which cooperation is not associated with one or more of these predictors. We propose an alternative evolutionary path towards the emergence of cooperation that accounts for the disparities observed in the current literature. We find that when dispersal is mediated by a group mode of dispersal, commonly termed budding dispersal, our mathematical model reveals an association between cooperation and immigration, lower costs of dispersal, low population density and environmental variability. Furthermore, by studying the continuum from the individual to the partial and full budding mode of dispersal, we can explicitly explain why the correlates of cooperation change under budding. This enables us to outline a general model for the evolution of cooperation that accounts for a substantial amount of empirical evidence. Our results suggest that natural selection may have favoured two major contrasting pathways for the evolution of cooperation depending on a set of key ecological and demographic factors.}, }
@article {pmid29664006, year = {2018}, author = {Jiang, W and Wei, Y and Long, Y and Owen, A and Wang, B and Wu, X and Luo, S and Dang, Y and Ma, DK}, title = {A genetic program mediates cold-warming response and promotes stress-induced phenoptosis in C. elegans.}, journal = {eLife}, volume = {7}, number = {}, pages = {}, pmid = {29664006}, issn = {2050-084X}, support = {R01 AG032435/AG/NIA NIH HHS/United States ; R01 GM117461/GM/NIGMS NIH HHS/United States ; R00HL116654/HL/NHLBI NIH HHS/United States ; R00 HL116654/HL/NHLBI NIH HHS/United States ; R01GM117461/GM/NIGMS NIH HHS/United States ; R01AG032435/AG/NIA NIH HHS/United States ; }, mesh = {Animals ; Basic-Leucine Zipper Transcription Factors/*metabolism ; Caenorhabditis elegans/*physiology/*radiation effects ; Caenorhabditis elegans Proteins/*metabolism ; *Cold Temperature ; *Gene Expression Regulation ; Gene Regulatory Networks ; *Stress, Physiological ; }, abstract = {How multicellular organisms respond to and are impacted by severe hypothermic stress is largely unknown. From C. elegans screens for mutants abnormally responding to cold-warming stimuli, we identify a molecular genetic pathway comprising ISY-1, a conserved uncharacterized protein, and ZIP-10, a bZIP-type transcription factor. ISY-1 gatekeeps the ZIP-10 transcriptional program by regulating the microRNA mir-60. Downstream of ISY-1 and mir-60, zip-10 levels rapidly and specifically increase upon transient cold-warming exposure. Prolonged zip-10 up-regulation induces several protease-encoding genes and promotes stress-induced organismic death, or phenoptosis, of C. elegans. zip-10 deficiency confers enhanced resistance to prolonged cold-warming stress, more prominently in adults than larvae. We conclude that the ZIP-10 genetic program mediates cold-warming response and may have evolved to promote wild-population kin selection under resource-limiting and thermal stress conditions.}, }
@article {pmid29657778, year = {2018}, author = {Mattison, SM and Seabright, E and Reynolds, AZ and Cao, JB and Brown, MJ and Feldman, MW}, title = {Adopted daughters and adopted daughters-in-law in Taiwan: a mortality analysis.}, journal = {Royal Society open science}, volume = {5}, number = {3}, pages = {171745}, pmid = {29657778}, issn = {2054-5703}, abstract = {Adoption is sometimes considered paradoxical from an evolutionary perspective because the costs spent supporting an adopted child would be better spent on rearing one's own. Kin selection theory is commonly used to solve this paradox, because the adoption of closely related kin contributes to the inclusive fitness of the adoptive parent. In this paper, we perform a novel test of kin selection theory in the context of adoption by asking whether adopted daughters-in-law, who contribute directly (i.e. genealogically) to the perpetuation of their adoptive families' lineages, experience lower mortality than daughters adopted for other purposes in historical Taiwan. We show that both classes of adopted daughter suffer lower mortality than biological daughters, but that the protective effect of adoption is stronger among daughters who were not adopted with the intention of perpetuating the family lineage. We speculate as to the possible benefits of such a pattern and emphasize the need to move beyond typological definitions of adoption to understand the specific costs and benefits involved in different forms of caring for others' children.}, }
@article {pmid29624797, year = {2018}, author = {Yirmiya, K and Segal, NL and Bloch, G and Knafo-Noam, A}, title = {Prosocial and self-interested intra-twin pair behavior in monozygotic and dizygotic twins in the early to middle childhood transition.}, journal = {Developmental science}, volume = {21}, number = {6}, pages = {e12665}, doi = {10.1111/desc.12665}, pmid = {29624797}, issn = {1467-7687}, support = {//The Science of Generosity Initiative, funded by the Templeton Foundation/International ; 240994//European Research Council (ERC)/International ; }, mesh = {Child ; Child, Preschool ; Humans ; *Social Behavior ; Task Performance and Analysis ; Twins, Dizygotic/*psychology ; Twins, Monozygotic/*psychology ; Work Engagement ; }, abstract = {Several related and complementary theoretical frameworks have been proposed to explain the existence of prosocial behavior, despite its potential fitness cost to the individual. These include kin selection theory, proposing that organisms have a propensity to help those to whom they are genetically related, and reciprocity, referring to the benefit of being prosocial, depending on past and future mutual interactions. A useful paradigm to examine prosociality is to compare mean levels of this behavior between monozygotic (MZ) and dizygotic (DZ) twins. Here, we examined the performance of 883 6.5-year-old twins (139 MZ and 302 DZ same-sex 6.5-year-old full twin pairs) in the Differential Productivity Task. In this task, the twins' behaviors were observed under two conditions: working for themselves vs. working for their co-twin. There were no significant differences between the performances of MZ and DZ twins in the prosocial condition of the task. Correlations within the twin dyads were significantly higher in MZ than DZ twins in the self-interested condition. However, similar MZ and DZ correlations were found in the prosocial condition, supporting the role of reciprocity in twins' prosociality towards each other.}, }
@article {pmid29622934, year = {2018}, author = {Bebbington, K and Fairfield, EA and Spurgin, LG and Kingma, SA and Dugdale, H and Komdeur, J and Richardson, DS}, title = {Joint care can outweigh costs of nonkin competition in communal breeders.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {29}, number = {1}, pages = {169-178}, pmid = {29622934}, issn = {1045-2249}, abstract = {Competition between offspring can greatly influence offspring fitness and parental investment decisions, especially in communal breeders where unrelated competitors have less incentive to concede resources. Given the potential for escalated conflict, it remains unclear what mechanisms facilitate the evolution of communal breeding among unrelated females. Resolving this question requires simultaneous consideration of offspring in noncommunal and communal nurseries, but such comparisons are missing. In the Seychelles warbler Acrocephalus sechellensis, we compare nestling pairs from communal nests (2 mothers) and noncommunal nests (1 mother) with singleton nestlings. Our results indicate that increased provisioning rate can act as a mechanism to mitigate the costs of offspring rivalry among nonkin. Increased provisioning in communal broods, as a consequence of having 2 female parents, mitigates any elevated costs of offspring rivalry among nonkin: per-capita provisioning and survival was equal in communal broods and singletons, but lower in noncommunal broods. Individual offspring costs were also more divergent in noncommunal broods, likely because resource limitation exacerbates differences in competitive ability between nestlings. It is typically assumed that offspring rivalry among nonkin will be more costly because offspring are not driven by kin selection to concede resources to their competitors. Our findings are correlational and require further corroboration, but may help explain the evolutionary maintenance of communal breeding by providing a mechanism by which communal breeders can avoid these costs.}, }
@article {pmid29607032, year = {2018}, author = {Mukai, H and Hironaka, M and Tojo, S and Nomakuchi, S}, title = {Maternal hatching synchronization in a subsocial burrower bug mitigates the risk of future sibling cannibalism.}, journal = {Ecology and evolution}, volume = {8}, number = {6}, pages = {3376-3381}, pmid = {29607032}, issn = {2045-7758}, abstract = {Sibling cannibalism-the killing and consumption of conspecifics within broods-carries a high risk of direct and inclusive fitness loss for parents and offspring. We reported previously that a unique vibrational behavior shown by the mother of the subsocial burrower bug, Adomerus rotundus (Heteroptera: Cydnidae), induced synchronous hatching. Maternal regulation may be one of the most effective mechanisms for preventing or limiting sibling cannibalism. Here, we tested the hypothesis that synchronous hatching induced by maternal vibration in A. rotundus prevents sibling cannibalism. Mothers and their mature egg masses were allocated to three groups: synchronous hatching by maternal vibration (SHmv), synchronous hatching by artificial vibration (SHav), and asynchronous hatching (AH). We then investigated the influence of each hatching strategy on the occurrence of sibling cannibalism of eggs and early-instar nymphs in the laboratory. No difference in the proportion of eggs cannibalized was observed among the three groups. However, the proportion of nymphs cannibalized was higher in the AH group than in the SHmv group. The difference in the number of days to first molting within clutch was significantly higher in the AH group than in the SHmv group. Junior nymphs were sometimes eaten by senior nymphs. However, immediately after molting, senior nymphs were at a high risk of being eaten by junior nymphs. Our results indicate that synchronous hatching of A. rotundus is necessary to mitigate the risk of sibling cannibalism.}, }
@article {pmid29607027, year = {2018}, author = {Best, R and Ruxton, GD and Gardner, A}, title = {Intragroup and intragenomic conflict over chemical defense against predators.}, journal = {Ecology and evolution}, volume = {8}, number = {6}, pages = {3322-3329}, pmid = {29607027}, issn = {2045-7758}, abstract = {Insects are often chemically defended against predators. There is considerable evidence for a group-beneficial element to their defenses, and an associated potential for individuals to curtail their own investment in costly defense while benefitting from the investments of others, termed "automimicry." Although females in chemically defended taxa often lay their eggs in clusters, leading to siblings living in close proximity, current models of automimicry have neglected kin-selection effects, which may be expected to curb the evolution of such selfishness. Here, we develop a general theory of automimicry that explicitly incorporates kin selection. We investigate how female promiscuity modulates intragroup and intragenomic conflicts overinvestment into chemical defense, finding that individuals are favored to invest less than is optimal for their group, and that maternal-origin genes favor greater investment than do paternal-origin genes. We translate these conflicts into readily testable predictions concerning gene expression patterns and the phenotypic consequences of genomic perturbations, and discuss how our results may inform gene discovery in relation to economically important agricultural products.}, }
@article {pmid29606788, year = {2018}, author = {Weiß, BM and Kücklich, M and Thomsen, R and Henkel, S and Jänig, S and Kulik, L and Birkemeyer, C and Widdig, A}, title = {Chemical composition of axillary odorants reflects social and individual attributes in rhesus macaques.}, journal = {Behavioral ecology and sociobiology}, volume = {72}, number = {4}, pages = {65}, pmid = {29606788}, issn = {0340-5443}, support = {P40 OD012217/OD/NIH HHS/United States ; }, abstract = {ABSTRACT: Scents play an important role in the life of most terrestrial mammals and may transmit valuable information about conspecifics. Olfaction was long considered of low importance in Old World monkeys due to their relative reduction of olfactory structures and low incidence of scent-marking behavior but has been increasingly recognized for mediating social relationships in recent years. Yet, studies investigating the composition of their chemical cues remain scarce. In the present study, we analyzed the potential information content of chemicals present on the skin of rhesus macaques (Macaca mulatta). We collected axillary secretions from 60 animals of the semifree-ranging population on Cayo Santiago (Puerto Rico, USA) with precleaned cotton swabs from which the secretions were subsequently extracted and analyzed by gas chromatography-mass spectrometry. Rhesus macaque axillary odorants varied in their overall similarity and composition. This variation was attributable to differences in sex, group membership, and kinship and further appeared to reflect age and rank in parts of our sample. The compounds most strongly associated with this variation primarily comprised larger molecular weight aldehydes and steroids. Such compounds are considered to be perceivable by the primate olfactory system through close-range interactions or through breakdown into smaller molecules by bacterial fermentation. Overall, our results provide additional evidence that odors of Old World monkeys reflect a wealth of potential information about their carrier, which provides the basis for chemical communication via body odors; however, its use by conspecifics needs to be confirmed in bioassays.<br><br>SIGNIFICANCE STATEMENT: One prerequisite for olfactory communication is the presence of systematic variation in animal odors that is related to attributes such as age, sex, or kinship. The composition of odors has been examined in numerous mammals but, with the exception of humans, remains poorly understood in Old World monkeys and apes, taxonomic groups in which most species do not show scent-marking behavior. In the present study, we show that the composition of axillary secretions of an Old World monkey, the rhesus macaque, reflects sex, group membership, relatedness, and possibly also age and rank. This variation thus provides a basis for olfactory communication in Old World monkeys.}, }
@article {pmid29593107, year = {2018}, author = {Shimoji, H and Kikuchi, T and Ohnishi, H and Kikuta, N and Tsuji, K}, title = {Social enforcement depending on the stage of colony growth in an ant.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1875}, pages = {}, pmid = {29593107}, issn = {1471-2954}, mesh = {*Altruism ; Animals ; Ants/genetics/*physiology ; Behavior, Animal/*physiology ; Biological Evolution ; DNA/genetics ; Female ; Genetic Variation/genetics ; Genotype ; Male ; Microsatellite Repeats/genetics ; Population Dynamics ; Reproduction/genetics/physiology ; Selection, Genetic ; }, abstract = {Altruism is a paradox in Darwinian evolution. Policing is an important mechanism of the evolution and maintenance of altruism. A recently developed dynamic game model incorporating colony demography and inclusive fitness predicts that, in hymenopteran social insects, policing behaviour enforcing reproductive altruism in group members depends strongly on the colony growth stage, with strong policing as the colony develops and a relaxation of policing during the reproductive phase. Here, we report clear evidence supporting this prediction. In the ant Diacamma sp., reproduction by workers was suppressed by worker policing when the colony was small, whereas in large, mature colonies worker policing was relaxed and worker-produced males emerged. Conditional expression of traits can provide strong empirical evidence for natural selection theory if the expression pattern is precisely predicted by the theory, and our results illustrate the importance of intracolony population dynamics in the evolution of social systems.}, }
@article {pmid29593076, year = {2018}, author = {Brügger, RK and Kappeler-Schmalzriedt, T and Burkart, JM}, title = {Reverse audience effects on helping in cooperatively breeding marmoset monkeys.}, journal = {Biology letters}, volume = {14}, number = {3}, pages = {}, pmid = {29593076}, issn = {1744-957X}, mesh = {Animals ; Callithrix/*physiology/psychology ; *Cooperative Behavior ; *Helping Behavior ; *Reproduction ; }, abstract = {Cooperatively breeding common marmosets show substantial variation in the amount of help they provide. Pay-to-stay and social prestige models of helping attribute this variation to audience effects, i.e. that individuals help more if group members can witness their interactions with immatures, whereas models of kin selection, group augmentation or those stressing the need to gain parenting experience do not predict any audience effects. We quantified the readiness of adult marmosets to share food in the presence or absence of other group members. Contrary to both predictions, we found a reverse audience effect on food-sharing behaviour: marmosets would systematically share more food with immatures when no audience was present. Thus, helping in common marmosets, at least in related family groups, does not support the pay-to-stay or the social prestige model, and helpers do not take advantage of the opportunity to engage in reputation management. Rather, the results appear to reflect a genuine concern for the immatures' well-being, which seems particularly strong when solely responsible for the immatures.}, }
@article {pmid29559642, year = {2018}, author = {Towers, JR and Hallé, MJ and Symonds, HK and Sutton, GJ and Morton, AB and Spong, P and Borrowman, JP and Ford, JKB}, title = {Infanticide in a mammal-eating killer whale population.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {4366}, pmid = {29559642}, issn = {2045-2322}, mesh = {Animals ; *Animals, Newborn ; *Behavior, Animal ; Bottle-Nosed Dolphin/psychology ; Drowning/*etiology ; Feeding Behavior/psychology ; Female ; Male ; Mothers/psychology ; Sexual Behavior, Animal ; Skin/injuries ; *Social Behavior ; Video Recording ; Vocalization, Animal ; Whale, Killer/*psychology ; Whales/psychology ; Wounds, Penetrating ; }, abstract = {Infanticide can be an extreme result of sexual conflict that drives selection in species in which it occurs. It is a rarely observed behaviour but some evidence for its occurrence in cetaceans exists in three species of dolphin. Here we describe observations of an adult male killer whale (Orcinus orca) and his post-reproductive mother killing a neonate belonging to an unrelated female from the same population in the North Pacific. This is the first account of infanticide reported in killer whales and the only case committed jointly by an adult male and his mother outside of humans. Consistent with findings in other social mammals, we suggest that infanticide is a sexually selected behaviour in killer whales that could provide subsequent mating opportunities for the infanticidal male and thereby provide inclusive fitness benefits for his mother.}, }
@article {pmid29558609, year = {2017}, author = {Schultner, E and Oettler, J and Helanterä, H}, title = {The Role of Brood in Eusocial Hymenoptera.}, journal = {The Quarterly review of biology}, volume = {92}, number = {1}, pages = {39-78}, doi = {10.1086/690840}, pmid = {29558609}, issn = {0033-5770}, mesh = {Animals ; *Behavior, Animal ; Female ; Hymenoptera/*physiology ; Male ; Population Dynamics ; *Social Behavior ; }, abstract = {Study of social traits in offspring traditionally reflects on interactions in simple family groups, with famous examples including parent-offspring conflict and sibling rivalry in birds and mammals. In contrast, studies of complex social groups such as the societies of ants, bees, and wasps focus mainly on adults and, in particular, on traits and interests of queens and workers. The social role of developing individuals in complex societies remains poorly understood. We attempt to fill this gap by illustrating that development in social Hymenoptera constitutes a crucial life stage with important consequences for the individual as well as the colony. We begin by describing the complex social regulatory network that modulates development in Hymenoptera societies. By highlighting the inclusive fitness interests of developing individuals, we show that they may differ from those of other colony members. We then demonstrate that offspring have evolved specialized traits that allow them to play a functional, cooperative role within colonies and give them the potential power to act toward increasing their inclusive fitness. We conclude by providing testable predictions for investigating the role of brood in colony interactions and giving a general outlook on what can be learned from studying offspring traits in hymenopteran societies.}, }
@article {pmid29543401, year = {2018}, author = {Leedale, AE and Sharp, SP and Simeoni, M and Robinson, EJH and Hatchwell, BJ}, title = {Fine-scale genetic structure and helping decisions in a cooperatively breeding bird.}, journal = {Molecular ecology}, volume = {27}, number = {7}, pages = {1714-1726}, doi = {10.1111/mec.14553}, pmid = {29543401}, issn = {1365-294X}, mesh = {Animals ; *Breeding ; Female ; Male ; Nesting Behavior ; Passeriformes/*genetics ; Phylogeny ; }, abstract = {In animal societies, characteristic demographic and dispersal patterns may lead to genetic structuring of populations, generating the potential for kin selection to operate. However, even in genetically structured populations, social interactions may still require kin discrimination for cooperative behaviour to be directed towards relatives. Here, we use molecular genetics and long-term field data to investigate genetic structure in an adult population of long-tailed tits Aegithalos caudatus, a cooperative breeder in which helping occurs within extended kin networks, and relate this to patterns of helping with respect to kinship. Spatial autocorrelation analyses reveal fine-scale genetic structure within our population, such that related adults of either sex are spatially clustered following natal dispersal, with relatedness among nearby males higher than that among nearby females, as predicted by observations of male-biased philopatry. This kin structure creates opportunities for failed breeders to gain indirect fitness benefits via redirected helping, but crucially, most close neighbours of failed breeders are unrelated and help is directed towards relatives more often than expected by indiscriminate helping. These findings are consistent with the effective kin discrimination mechanism known to exist in long-tailed tits and support models identifying kin selection as the driver of cooperation.}, }
@article {pmid29525917, year = {2018}, author = {Haemmerli, S and Thill, C and Amici, F and Cacchione, T}, title = {Domestic horses (Equus ferus caballus) fail to intuitively reason about object properties like solidity and weight.}, journal = {Animal cognition}, volume = {21}, number = {3}, pages = {441-446}, doi = {10.1007/s10071-018-1177-z}, pmid = {29525917}, issn = {1435-9456}, mesh = {Animals ; *Cognition ; Female ; Form Perception ; Horses/*psychology ; Learning ; Male ; Reward ; *Visual Perception ; }, abstract = {From early infancy, humans reason about the external world in terms of identifiable, solid, cohesive objects persisting in space and time. This is one of the most fundamental human skills, which may be part of our innate conception of object properties. Although object permanence has been extensively studied across a variety of taxa, little is known about how non-human animals reason about other object properties. In this study, we therefore tested how domestic horses (Equus ferus caballus) intuitively reason about object properties like solidity and height, to locate hidden food. Horses were allowed to look for a food reward behind two opaque screens, only one of which had either the proper height or inclination to hide food rewards. Our results suggest that horses could not intuitively reason about physical object properties, but rather learned to select the screen with the proper height or inclination from the second set of 5 trials.}, }
@article {pmid29515868, year = {2018}, author = {Thomas, MG and Ji, T and Wu, J and He, Q and Tao, Y and Mace, R}, title = {Kinship underlies costly cooperation in Mosuo villages.}, journal = {Royal Society open science}, volume = {5}, number = {2}, pages = {171535}, pmid = {29515868}, issn = {2054-5703}, abstract = {The relative importance of social evolution theories such as kin selection, direct reciprocity and need-based transfers in explaining real-world cooperation is the source of much debate. Previous field studies of cooperation in human communities have revealed variability in the extent to which each of these theories explains human sociality in different contexts. We conducted multivariate social network analyses predicting costly cooperation-labouring on another household's farm-in 128 082 dyads of Mosuo farming households in southwest China. Through information-theoretic model selection, we tested the roles played by genealogical relatedness, affinal relationships (including reproductive partners), reciprocity, relative need, wealth, household size, spatial proximity and gift-giving in an economic game. The best-fitting model included all factors, along with interactions between relatedness and (i) reciprocity, (ii) need, (iii) the presence of own children in another household and (iv) proximity. Our results show how a real-world form of cooperation was driven by kinship. Households tended to help kin in need (but not needy non-kin) and travel further to help spatially distant relatives. Households were more likely to establish reciprocal relationships with distant relatives and non-kin but closer kin cooperated regardless of reciprocity. These patterns of kin-driven cooperation show the importance of inclusive fitness in understanding human social behaviour.}, }
@article {pmid29515836, year = {2018}, author = {Lehtonen, J and Schwanz, LE}, title = {Mate limitation and sex ratio evolution.}, journal = {Royal Society open science}, volume = {5}, number = {2}, pages = {171135}, pmid = {29515836}, issn = {2054-5703}, abstract = {Sex ratio evolution has been one of the most successful areas of evolutionary theory. Pioneered by Düsing and Fisher under panmixia, and later extended by Hamilton to cover local mate competition (LMC), these models often assume, either implicitly or explicitly, that all females are fertilized. Here, we examine the effects of relaxing this assumption, under both panmictic and LMC models with diploid genetics. We revisit the question of the mathematical relationship between sex ratio and probability of fertilization, and use these results to model sex ratio evolution under risk of incomplete fertilization. We find that (i) under panmixia, mate limitation has no effect on the evolutionarily stable strategy (ESS) sex allocation; (ii) under LMC, mate limitation can make sex allocation less female-biased than under complete fertilization; (iii) contrary to what is occasionally stated, a significant fraction of daughters can remain unfertilized at the ESS in LMC with mate limitation; (iv) with a commonly used mating function, the fraction of unfertilized daughters can be quite large, and (v) with more realistic fertilization functions, the deviation becomes smaller. The models are presented in three equivalent forms: individual selection, kin selection and group selection. This serves as an example of the equivalence of the methods, while each approach has their own advantages. We discuss possible extensions of the model to haplodiploidy.}, }
@article {pmid29514963, year = {2018}, author = {Schweinfurth, MK and Taborsky, M}, title = {Relatedness decreases and reciprocity increases cooperation in Norway rats.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1874}, pages = {}, pmid = {29514963}, issn = {1471-2954}, mesh = {Animals ; *Cooperative Behavior ; *Decision Making ; Male ; Rats/*genetics/*psychology ; *Social Behavior ; }, abstract = {Kin selection and reciprocity are two mechanisms underlying the evolution of cooperation, but the relative importance of kinship and reciprocity for decisions to cooperate are yet unclear for most cases of cooperation. Here, we experimentally tested the relative importance of relatedness and received cooperation for decisions to help a conspecific in wild-type Norway rats (Rattus norvegicus). Test rats provided more food to non-kin than to siblings, and they generally donated more food to previously helpful social partners than to those that had refused help. The rats thus applied reciprocal cooperation rules irrespective of relatedness, highlighting the importance of reciprocal help for cooperative interactions among both related and unrelated conspecifics.}, }
@article {pmid29513655, year = {2018}, author = {Kennedy, P and Higginson, AD and Radford, AN and Sumner, S}, title = {Altruism in a volatile world.}, journal = {Nature}, volume = {555}, number = {7696}, pages = {359-362}, pmid = {29513655}, issn = {1476-4687}, support = {682253/ERC_/European Research Council/International ; }, mesh = {*Altruism ; Animals ; *Biological Evolution ; Genetic Fitness ; Genotype ; Models, Biological ; Reproduction/genetics/physiology ; Selection, Genetic ; Stochastic Processes ; }, abstract = {The evolution of altruism-costly self-sacrifice in the service of others-has puzzled biologists since The Origin of Species. For half a century, attempts to understand altruism have developed around the concept that altruists may help relatives to have extra offspring in order to spread shared genes. This theory-known as inclusive fitness-is founded on a simple inequality termed Hamilton's rule. However, explanations of altruism have typically not considered the stochasticity of natural environments, which will not necessarily favour genotypes that produce the greatest average reproductive success. Moreover, empirical data across many taxa reveal associations between altruism and environmental stochasticity, a pattern not predicted by standard interpretations of Hamilton's rule. Here we derive Hamilton's rule with explicit stochasticity, leading to new predictions about the evolution of altruism. We show that altruists can increase the long-term success of their genotype by reducing the temporal variability in the number of offspring produced by their relatives. Consequently, costly altruism can evolve even if it has a net negative effect on the average reproductive success of related recipients. The selective pressure on volatility-suppressing altruism is proportional to the coefficient of variation in population fitness, and is therefore diminished by its own success. Our results formalize the hitherto elusive link between bet-hedging and altruism, and reveal missing fitness effects in the evolution of animal societies.}, }
@article {pmid29507206, year = {2018}, author = {Noh, S and Geist, KS and Tian, X and Strassmann, JE and Queller, DC}, title = {Genetic signatures of microbial altruism and cheating in social amoebas in the wild.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {12}, pages = {3096-3101}, pmid = {29507206}, issn = {1091-6490}, mesh = {Adaptation, Physiological ; Dictyostelium/*genetics/*physiology ; Evolution, Molecular ; Gene Expression Regulation ; Genetic Variation ; Genome, Protozoan ; Selection, Genetic ; }, abstract = {Many microbes engage in social interactions. Some of these have come to play an important role in the study of cooperation and conflict, largely because, unlike most animals, they can be genetically manipulated and experimentally evolved. However, whereas animal social behavior can be observed and assessed in natural environments, microbes usually cannot, so we know little about microbial social adaptations in nature. This has led to some difficult-to-resolve controversies about social adaptation even for well-studied traits such as bacterial quorum sensing, siderophore production, and biofilms. Here we use molecular signatures of population genetics and molecular evolution to address controversies over the existence of altruism and cheating in social amoebas. First, we find signatures of rapid adaptive molecular evolution that are consistent with social conflict being a significant force in nature. Second, we find population-genetic signatures of purifying selection to support the hypothesis that the cells that form the sterile stalk evolve primarily through altruistic kin selection rather than through selfish direct reproduction. Our results show how molecular signatures can provide insight into social adaptations that cannot be observed in their natural context, and they support the hypotheses that social amoebas in the wild are both altruists and cheaters.}, }
@article {pmid29494630, year = {2018}, author = {Garay, J and Csiszár, V and Móri, TF and Szilágyi, A and Varga, Z and Számadó, S}, title = {Juvenile honest food solicitation and parental investment as a life history strategy: A kin demographic selection model.}, journal = {PloS one}, volume = {13}, number = {3}, pages = {e0193420}, pmid = {29494630}, issn = {1932-6203}, mesh = {Animals ; Feeding Behavior ; *Life History Traits ; Markov Chains ; *Models, Theoretical ; Phenotype ; Seasons ; }, abstract = {Parent-offspring communication remains an unresolved challenge for biologist. The difficulty of the challenge comes from the fact that it is a multifaceted problem with connections to life-history evolution, parent-offspring conflict, kin selection and signalling. Previous efforts mainly focused on modelling resource allocation at the expense of the dynamic interaction during a reproductive season. Here we present a two-stage model of begging where the first stage models the interaction between nestlings and parents within a nest and the second stage models the life-history trade-offs. We show in an asexual population that honest begging results in decreased variance of collected food between siblings, which leads to mean number of surviving offspring. Thus, honest begging can be seen as a special bet-hedging against informational uncertainty, which not just decreases the variance of fitness but also increases the arithmetic mean.}, }
@article {pmid29492037, year = {2018}, author = {Wright, CM and Hyland, TD and Izzo, AS and McDermott, DR and Tibbetts, EA and Pruitt, JN}, title = {Polistes metricus queens exhibit personality variation and behavioral syndromes.}, journal = {Current zoology}, volume = {64}, number = {1}, pages = {45-52}, pmid = {29492037}, issn = {1674-5507}, abstract = {Consistent differences in behavior between individuals, otherwise known as animal personalities, have become a staple in behavioral ecology due to their ability to explain a wide range of phenomena. Social organisms are especially serviceable to animal personality techniques because they can be used to explore behavioral variation at both the individual and group level. Despite the success of personality research in social organisms generally, and social Hymenoptera in particular, social wasps (Vespidae) have received little to no attention in the personality literature. In the present study, we test Polistes metricus (Vespidae; Polistinae) paper wasp queens for the presence of repeatable variation in, and correlations ("behavioral syndromes") between, several commonly used personality metrics: boldness, aggressiveness, exploration, and activity. Our results indicate that P. metricus queens exhibit personalities for all measured traits and correlations between different behavioral measures. Given that paper wasps have served as a model organism for a wide range of phenomena such as kin selection, dominance hierarchies, mate choice, facial recognition, social parasitism, and chemical recognition, we hope that our results will motivate researchers to explore whether, or to what degree, queen personality is important in their research programs.}, }
@article {pmid29491991, year = {2017}, author = {Dale, R and Marshall-Pescini, S and Range, F}, title = {Do females use their sexual status to gain resource access? Investigating food-for-sex in wolves and dogs.}, journal = {Current zoology}, volume = {63}, number = {3}, pages = {323-330}, pmid = {29491991}, issn = {1674-5507}, support = {311870/ERC_/European Research Council/International ; }, abstract = {While food sharing among related individuals can be explained by kin selection, food sharing between unrelated individuals has been more of an evolutionary puzzle. The food-for-sex hypothesis provides an explanation for the occurrence of food sharing among nonkin. However, little is known about the socio-ecological factors that can promote such a commodity exchange. A species mating system is a factor potentially influencing food-for-sex patterns of behavior. Here, we compared wolves, which form pair-bonds, with dogs, which are typically promiscuous in free-ranging contexts, to investigate the effect of reproductive stages on the behavior around a food source in 2 different contexts. Furthermore, we considered the roles of both the males and the females in the potential food-for-sex exchange. Results indicate that in both species and for both sexes the breeding period promotes decreased aggression. Additionally, females were more persistent in their attempts to access the food and were able to monopolize the resource more when in heat as compared to outside the breeding period. Finally, in dogs, but not wolves, females spent more time in proximity to the male's bone and had a shorter latency to start eating it when in heat. Overall, this study demonstrates that the food-for-sex hypothesis plays a part in intersexual food sharing in canids, and highlights the role of females in the interaction. These effects were especially the case in dogs, suggesting a potential effect of mating system on food-for-sex responses.}, }
@article {pmid29449670, year = {2018}, author = {Amici, F and Call, J and Watzek, J and Brosnan, S and Aureli, F}, title = {Social inhibition and behavioural flexibility when the context changes: a comparison across six primate species.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {3067}, pmid = {29449670}, issn = {2045-2322}, mesh = {Animals ; Atelinae/psychology ; Behavior, Animal/*physiology ; Cebus/psychology ; Food ; Gorilla gorilla/psychology ; Hominidae/*psychology ; *Learning ; Pan paniscus/psychology ; Pan troglodytes/psychology ; Pongo/psychology ; }, abstract = {The ability to inhibit previously employed strategies and flexibly adjust behavioural responses to external conditions may be critical for individual survival. However, it is unclear which factors predict their distribution across species. Here, we investigated social inhibition and behavioural flexibility in six primate species (chimpanzees, bonobos, orangutans, gorillas, capuchin monkeys and spider monkeys) differing in terms of phylogenetic relatedness, foraging ecology and social organization. Depending on the social context, individuals could maximize their food intake by inhibiting the selection of a larger food reward in one condition (i.e. inhibition), but not in others, which required them to flexibly switching strategies across conditions (i.e. behavioural flexibility). Overall, our study revealed inter-specific differences in social inhibition and behavioural flexibility, which partially reflected differences in fission-fusion dynamics. In particular, orangutans and chimpanzees showed the highest level of inhibitory skills, while gorillas and capuchin monkeys showed the lowest one. In terms of behavioural flexibility, orangutans and spider monkeys were the best performers, while bonobos and capuchin monkeys were the worst ones. These results contribute to our understanding that inhibition and behavioural flexibility may be linked in more complex ways than usually thought, although both abilities play a crucial role in efficient problem solving.}, }
@article {pmid29438052, year = {2018}, author = {Brahma, A and Mandal, S and Gadagkar, R}, title = {Current indirect fitness and future direct fitness are not incompatible.}, journal = {Biology letters}, volume = {14}, number = {2}, pages = {}, pmid = {29438052}, issn = {1744-957X}, mesh = {Animals ; Behavior, Animal/*physiology ; Feeding Behavior ; Female ; Genetic Fitness/*physiology ; Social Behavior ; Wasps/*physiology ; }, abstract = {In primitively eusocial insects, many individuals function as workers despite being capable of independent reproduction. Such altruistic behaviour is usually explained by the argument that workers gain indirect fitness by helping close genetic relatives. The focus on indirect fitness has left open the question of whether workers are also capable of getting direct fitness in the future in spite of working towards indirect fitness in the present. To investigate this question, we recorded behavioural profiles of all wasps on six naturally occurring nests of Ropalidia marginata, and then isolated all wasps in individual plastic boxes, giving them an opportunity to initiate nests and lay eggs. We found that 41% of the wasps successfully did so. Compared to those that failed to initiate nests, those that did were significantly younger, had significantly higher frequency of self-feeding behaviour on their parent nests but were not different in the levels of work performed in the parent nests. Thus ageing and poor feeding, rather than working for their colonies, constrain individuals for future independent reproduction. Hence, future direct fitness and present work towards gaining indirect fitness are not incompatible, making it easier for worker behaviour to be selected by kin selection or multilevel selection.}, }
@article {pmid29337077, year = {2018}, author = {Pande, S and Velicer, GJ}, title = {Chimeric Synergy in Natural Social Groups of a Cooperative Microbe.}, journal = {Current biology : CB}, volume = {28}, number = {2}, pages = {262-267.e3}, doi = {10.1016/j.cub.2017.11.043}, pmid = {29337077}, issn = {1879-0445}, mesh = {*Chimera ; *Microbial Interactions ; Myxococcus xanthus/*physiology ; Spores, Bacterial/physiology ; }, abstract = {Many cooperative species form internally diverse social groups in which individual fitness depends significantly on group-level productivity from cooperation [1-4]. For such species, selection is expected to often disfavor within-group diversity that reduces cooperative productivity [5, 6]. While diversity within social groups is known to enhance productivity in some animals [7-9], diversity within natural groups of social microbes is largely unexamined in this regard. Cells of the soil bacterium Myxococcus xanthus respond to starvation by constructing multicellular fruiting bodies within each of which a subpopulation of cells transforms into stress-resistant spores [10]. Fruiting bodies isolated from soil often harbor substantial endemic diversity [11] that is, nonetheless, lower than between-group diversity, which increases with distance from millimeter to global scales [12-14]. We show that M. xanthus clones isolated from the same fruiting body often collectively produce more viable spores in chimeric groups than expected from sporulation in genetically homogeneous groups. In contrast, chimerism among clones derived from different fruiting bodies tends to reduce group productivity, and it does so increasingly as a function of spatial distance between fruiting-body sample sites. For one fruiting body examined in detail, chimeric synergy-a positive quantitative effect of chimerism on group productivity-is distributed broadly across an interaction network rather than limited to a few interactions. We propose that these results strengthen the plausibility of the hypothesis that selection may operate not only within Myxococcus groups, but also between kin groups to disfavor within-group variation that reduces productivity while allowing some forms of diversity that generate chimeric synergy to persist.}, }
@article {pmid29295937, year = {2018}, author = {Wang, C and Lu, X}, title = {Hamilton's inclusive fitness maintains heritable altruism polymorphism through rb = c.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {8}, pages = {1860-1864}, pmid = {29295937}, issn = {1091-6490}, mesh = {*Altruism ; Animals ; Behavior, Animal ; Birds/*genetics ; Female ; *Genetic Fitness ; Genotype ; Male ; *Models, Genetic ; *Polymorphism, Genetic ; Social Behavior ; }, abstract = {How can altruism evolve or be maintained in a selfish world? Hamilton's rule shows that the former process will occur when rb > c-the benefits to the recipients of an altruistic act b, weighted by the relatedness between the social partners r, exceed the costs to the altruists c-drives altruistic genotypes spreading against nonaltruistic ones. From this rule, we infer that altruistic genotypes will persist in a population by forming a stable heritable polymorphism with nonaltruistic genotypes if rb = c makes inclusive fitness of the two morphs equal. We test this prediction using the data of 12 years of study on a cooperatively breeding bird, the Tibetan ground tit Pseudopodoces humilis, where helping is performed by males only and kin-directed. Individual variation in ever acting as a helper was heritable (h[2] = 0.47), and the resultant altruism polymorphism remained stable as indicated by low-level annual fluctuation of the percentage of helpers among all adult males (24-28%). Helpers' indirect fitness gains from increased lifetime reproductive success of related breeders statistically fully compensated for their lifetime direct fitness losses, suggesting that rb = c holds. While our work provides a fundamental support for Hamilton's idea, it highlights the equivalent inclusive fitness returns to altruists and nonaltruists mediated by rb = c as a theoretically and realistically important mechanism to maintain social polymorphism.}, }
@article {pmid29289605, year = {2018}, author = {Yamauchi, A and van Baalen, M and Sabelis, MW}, title = {Spatial patterns generated by simultaneous cooperation and exploitation favour the evolution of altruism.}, journal = {Journal of theoretical biology}, volume = {441}, number = {}, pages = {58-67}, doi = {10.1016/j.jtbi.2017.12.027}, pmid = {29289605}, issn = {1095-8541}, mesh = {*Algorithms ; *Altruism ; Animals ; *Biological Evolution ; Computer Simulation ; Humans ; *Models, Theoretical ; *Social Behavior ; }, abstract = {In kin selection theory in the evolution of social behaviours, the relatedness between interacting individuals is influenced by the spatial structure of the population. It is generally considered that in the 'viscous' population competition among individuals tends to suppress the evolution of altruism. We consider that more complex interactions produce specific spatial patterns in the presence of competitive interaction, which could alter the process of kin selection in a given space. Here, we theoretically studied the joint evolution of altruism and resource exploitation in a spatially structured population. The simulations indicated that joint evolution can result in self-organisation of regularly arranged cluster structures, which creates a new 'level of selection', and significantly promotes the evolution of altruism through a promotion of kin selection. The analysis also suggested synergetic effects of the joint evolution of two traits, including an evolutionary suicide of the population.}, }
@article {pmid29244566, year = {2018}, author = {Lehtonen, J}, title = {The Price Equation, Gradient Dynamics, and Continuous Trait Game Theory.}, journal = {The American naturalist}, volume = {191}, number = {1}, pages = {146-153}, doi = {10.1086/694891}, pmid = {29244566}, issn = {1537-5323}, mesh = {*Biological Evolution ; *Game Theory ; *Genetic Fitness ; Models, Genetic ; }, abstract = {A recent article convincingly nominated the Price equation as the fundamental theorem of evolution and used it as a foundation to derive several other theorems. A major section of evolutionary theory that was not addressed is that of game theory and gradient dynamics of continuous traits with frequency-dependent fitness. Deriving fundamental results in these fields under the unifying framework of the Price equation illuminates similarities and differences between approaches and allows a simple, unified view of game-theoretical and dynamic concepts. Using Taylor polynomials and the Price equation, I derive a dynamic measure of evolutionary change, a condition for singular points, the convergence stability criterion, and an alternative interpretation of evolutionary stability. Furthermore, by applying the Price equation to a multivariable Taylor polynomial, the direct fitness approach to kin selection emerges. Finally, I compare these results to the mean gradient equation of quantitative genetics and the canonical equation of adaptive dynamics.}, }
@article {pmid29244555, year = {2018}, author = {Lion, S}, title = {Theoretical Approaches in Evolutionary Ecology: Environmental Feedback as a Unifying Perspective.}, journal = {The American naturalist}, volume = {191}, number = {1}, pages = {21-44}, doi = {10.1086/694865}, pmid = {29244555}, issn = {1537-5323}, mesh = {Adaptation, Biological ; *Biological Evolution ; Ecology/*methods ; Feedback ; *Game Theory ; Gene Frequency ; Genetic Fitness ; *Models, Genetic ; }, abstract = {Evolutionary biology and ecology have a strong theoretical underpinning, and this has fostered a variety of modeling approaches. A major challenge of this theoretical work has been to unravel the tangled feedback loop between ecology and evolution. This has prompted the development of two main classes of models. While quantitative genetics models jointly consider the ecological and evolutionary dynamics of a focal population, a separation of timescales between ecology and evolution is assumed by evolutionary game theory, adaptive dynamics, and inclusive fitness theory. As a result, theoretical evolutionary ecology tends to be divided among different schools of thought, with different toolboxes and motivations. My aim in this synthesis is to highlight the connections between these different approaches and clarify the current state of theory in evolutionary ecology. Central to this approach is to make explicit the dependence on environmental dynamics of the population and evolutionary dynamics, thereby materializing the eco-evolutionary feedback loop. This perspective sheds light on the interplay between environmental feedback and the timescales of ecological and evolutionary processes. I conclude by discussing some potential extensions and challenges to our current theoretical understanding of eco-evolutionary dynamics.}, }
@article {pmid29234885, year = {2018}, author = {Gleichsner, AM and Reinhart, K and Minchella, DJ}, title = {The influence of related and unrelated co-infections on parasite dynamics and virulence.}, journal = {Oecologia}, volume = {186}, number = {2}, pages = {555-564}, pmid = {29234885}, issn = {1432-1939}, mesh = {Animals ; *Coinfection ; Host-Parasite Interactions ; *Parasites ; *Parasitic Diseases ; Virulence ; }, abstract = {Many parasitic infections increase the morbidity and mortality of host populations. Interactions between co-infecting parasites can influence virulence, the damage done to a host. Previous studies investigating the impacts of parasite co-infection on hosts have been limited by their inability to control parasite dosage, use consistent virulence metrics, or verify co-infection status. This study used molecular tools, known infection dosage, and multiple assessments over time to test whether parasite relatedness can predict virulence in co-infections, as well as whether competitive interactions between different parasite strains within a host are predictable over time. In addition, we examined the impacts of other parasite traits, such as infectivity, as alternative predictors of virulence and competition outcomes. Hosts with single-strain (related) parasite infections were found to have lower virulence in terms of host and parasite reproduction, supporting kin selection predictions. However, these infections also resulted in higher host mortality. We argue that mortality should not be used as a measurement of virulence in parasite systems that castrate hosts. Hosts were more susceptible to mixed strain (unrelated) parasite infections, indicating that co-infections may make resistance more costly to hosts. Co-infections were dynamic, with changes in parasite dominance over the course of the infection. The more infective parasite strain appeared to suppress the less infective strain, ultimately increasing host longevity. Our findings suggest that unrelated, or more diverse, parasite infections are associated with higher virulence, but that studies must consider their methodology and possible alternative explanations beyond kin selection to understand virulence outcomes.}, }
@article {pmid29206171, year = {2017}, author = {Levin, SR and West, SA}, title = {Kin Selection in the RNA World.}, journal = {Life (Basel, Switzerland)}, volume = {7}, number = {4}, pages = {}, pmid = {29206171}, issn = {2075-1729}, abstract = {Various steps in the RNA world required cooperation. Why did life's first inhabitants, from polymerases to synthetases, cooperate? We develop kin selection models of the RNA world to answer these questions. We develop a very simple model of RNA cooperation and then elaborate it to model three relevant issues in RNA biology: (1) whether cooperative RNAs receive the benefits of cooperation; (2) the scale of competition in RNA populations; and (3) explicit replicator diffusion and survival. We show: (1) that RNAs are likely to express partial cooperation; (2) that RNAs will need mechanisms for overcoming local competition; and (3) in a specific example of RNA cooperation, persistence after replication and offspring diffusion allow for cooperation to overcome competition. More generally, we show how kin selection can unify previously disparate answers to the question of RNA world cooperation.}, }
@article {pmid29195838, year = {2018}, author = {Sanches, VH and Kuraoka, DVH and Almeida, PR and Goldman, C}, title = {A phenomenological analysis of eco-evolutionary coupling under dilution.}, journal = {Journal of theoretical biology}, volume = {438}, number = {}, pages = {156-164}, doi = {10.1016/j.jtbi.2017.11.019}, pmid = {29195838}, issn = {1095-8541}, mesh = {*Biological Evolution ; *Ecosystem ; *Models, Biological ; Numerical Analysis, Computer-Assisted ; Saccharomyces cerevisiae/metabolism ; Time Factors ; }, abstract = {Evolutionary dynamics experienced by mixed microbial populations of cooperators and cheaters has been examined in experiments in the literature using a protocol of periodic dilution to investigate the properties of resilience and adaptability to environmental changes. Data depicted on an appropriate phase diagram indicate, among other features, a stable equilibrium point at which cooperators and cheaters coexist (Sanchez and Gore, 2013). We present here a phenomenological analysis of these data focusing on an eco-evolutionary-game perspective. To that end, we work on an extension of the model proposed in Tao and Cressman (2007). It's original version takes into account changes of the total population density while the individuals experience a pairwise Prisoners Dilemma game. The extension devised here contains a dilution parameter to conform with the experimental procedure, in addition to a term accounting for Allee effects. In contrast to other descriptions proposed in similar contexts, however, the model here does not account for assortative encounters, group or kin selection. Nonetheless, it describes surprisingly well both qualitatively and quantitatively the features of the observed phase diagram. We discuss these results in terms of the behavior of an effective payoff matrix defined accordingly.}, }
@article {pmid29179582, year = {2017}, author = {Zhang, J}, title = {Is Support of Censoring Controversial Media Content for the Good of Others? Sexual Strategies and Support of Censoring Pro-Alcohol Advertising.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {15}, number = {4}, pages = {1474704917742808}, pmid = {29179582}, issn = {1474-7049}, mesh = {Adolescent ; Adult ; *Advertising ; *Alcohol Drinking ; *Alcoholic Beverages ; Female ; Humans ; Male ; *Sexual Behavior ; United States ; Young Adult ; }, abstract = {At least in the United States, there are widespread concerns with advertising that encourages alcohol consumption, and previous research explains those concerns as aiming to protect others from the harm of excessive alcohol use.[1] Drawing on sexual strategies theory, we hypothesized that support of censoring pro-alcohol advertising is ultimately self-benefiting regardless of its altruistic effect at a proximate level. Excessive drinking positively correlates with having casual sex, and casual sex threatens monogamy, one of the major means with which people adopting a long-term sexual strategy increase their inclusive fitness. Then, one way for long-term strategists to protect monogamy, and thus their reproductive interest is to support censoring pro-alcohol advertising, thereby preventing others from becoming excessive drinkers (and consequently having casual sex) under media influence. Supporting this hypothesis, three studies consistently showed that restricted sociosexuality positively correlated with support of censoring pro-alcohol advertising before and after various value-, ideological-, and moral-foundation variables were controlled for. Also as predicted, Study 3 revealed a significant indirect effect of sociosexuality on censorship support through perceived media influence on others but not through perceived media influence on self. These findings further supported a self-interest analysis of issue opinions, extended third-person-effect research on support of censoring pro-alcohol advertising, and suggested a novel approach to analyzing media censorship support.}, }
@article {pmid29166167, year = {2017}, author = {Riehl, C}, title = {Kinship and Incest Avoidance Drive Patterns of Reproductive Skew in Cooperatively Breeding Birds.}, journal = {The American naturalist}, volume = {190}, number = {6}, pages = {774-785}, doi = {10.1086/694411}, pmid = {29166167}, issn = {1537-5323}, mesh = {Animals ; Birds/*genetics/*physiology ; Female ; *Inbreeding ; Male ; Reproduction/physiology ; *Social Behavior ; Species Specificity ; }, abstract = {Social animals vary in how reproduction is divided among group members, ranging from monopolization by a dominant pair (high skew) to equal sharing by cobreeders (low skew). Despite many theoretical models, the ecological and life-history factors that generate this variation are still debated. Here I analyze data from 83 species of cooperatively breeding birds, finding that kinship within the breeding group is a powerful predictor of reproductive sharing across species. Societies composed of nuclear families have significantly higher skew than those that contain unrelated members, a pattern that holds for both multimale and multifemale groups. Within-species studies confirm this, showing that unrelated subordinates of both sexes are more likely to breed than related subordinates are. Crucially, subordinates in cooperative groups are more likely to breed if they are unrelated to the opposite-sex dominant, whereas relatedness to the same-sex dominant has no effect. This suggests that incest avoidance, rather than suppression by dominant breeders, may be an important proximate mechanism limiting reproduction by subordinates. Overall, these results support the ultimate evolutionary logic behind concessions models of skew-namely, that related subordinates gain indirect fitness benefits from helping at the nests of kin, so a lower direct reproductive share is required for selection to favor helping over dispersal-but not the proximate mechanism of dominant control assumed by these models.}, }
@article {pmid29142115, year = {2017}, author = {Lymbery, SJ and Simmons, LW}, title = {Males harm females less when competing with familiar relatives.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1867}, pages = {}, pmid = {29142115}, issn = {1471-2954}, mesh = {*Aggression ; Animals ; Coleoptera/*physiology ; Female ; Male ; *Sexual Behavior, Animal ; }, abstract = {Sexual conflict occurs when reproductive partners have different fitness optima, and can lead to the evolution of traits in one sex that inflict fitness costs on the opposite sex. Recently, it has been proposed that antagonism by males towards females should be reduced when they compete with relatives, because reducing the future productivity of a female would result in an indirect fitness cost for a harmful male. We tested this prediction in the seed beetle Callosobruchus maculatus, the males of which harm females with genital spines and pre-copulatory harassment. We compared lifespan, lifetime egg production and lifetime offspring production among females housed with groups of males that varied in their familiarity and relatedness. Females produced significantly more eggs and offspring when grouped with males who were both related and familiar to each other. There was no effect of male relatedness or familiarity on female lifespan. Our results suggest that males plastically adjust their harmfulness towards females in response to changes in inclusive fitness payoffs, and that in this species both genetic relatedness and social familiarity mediate this effect.}, }
@article {pmid29134064, year = {2017}, author = {Bertolaso, M and Dieli, AM}, title = {Cancer and intercellular cooperation.}, journal = {Royal Society open science}, volume = {4}, number = {10}, pages = {170470}, pmid = {29134064}, issn = {2054-5703}, abstract = {The major transitions approach in evolutionary biology has shown that the intercellular cooperation that characterizes multicellular organisms would never have emerged without some kind of multilevel selection. Relying on this view, the Evolutionary Somatic view of cancer considers cancer as a breakdown of intercellular cooperation and as a loss of the balance between selection processes that take place at different levels of organization (particularly single cell and individual organism). This seems an elegant unifying framework for healthy organism, carcinogenesis, tumour proliferation, metastasis and other phenomena such as ageing. However, the gene-centric version of Darwinian evolution, which is often adopted in cancer research, runs into empirical problems: proto-tumoural and tumoural features in precancerous cells that would undergo 'natural selection' have proved hard to demonstrate; cells are radically context-dependent, and some stages of cancer are poorly related to genetic change. Recent perspectives propose that breakdown of intercellular cooperation could depend on 'fields' and other higher-level phenomena, and could be even mutations independent. Indeed, the field would be the context, allowing (or preventing) genetic mutations to undergo an intra-organism process analogous to natural selection. The complexities surrounding somatic evolution call for integration between multiple incomplete frameworks for interpreting intercellular cooperation and its pathologies.}, }
@article {pmid29118238, year = {2017}, author = {Smith, D}, title = {Correction to 'O brother, where art thou? Investment in siblings for inclusive fitness benefits, not father absence, predicts earlier age at menarche'.}, journal = {Biology letters}, volume = {13}, number = {11}, pages = {}, pmid = {29118238}, issn = {1744-957X}, }
@article {pmid29109471, year = {2017}, author = {Gardner, A and Úbeda, F}, title = {The meaning of intragenomic conflict.}, journal = {Nature ecology &amp; evolution}, volume = {1}, number = {12}, pages = {1807-1815}, doi = {10.1038/s41559-017-0354-9}, pmid = {29109471}, issn = {2397-334X}, mesh = {*Biological Evolution ; Genetic Fitness ; *Genome ; Models, Genetic ; *Selection, Genetic ; }, abstract = {Recent years have seen an explosion of interest in genes that function for their own good and to the detriment of other genes that reside in the same genome. Such intragenomic conflicts are increasingly recognized to underpin maladaptation and disease. However, progress has been impeded by a lack of clear understanding regarding what intragenomic conflict actually means, and an associated obscurity concerning its fundamental drivers. Here we develop a general theory of intragenomic conflict in which genes are viewed as inclusive-fitness-maximizing agents that come into conflict when their inclusive-fitness interests disagree. This yields a classification of all intragenomic conflicts into three categories according to whether genes disagree about where they have come from, where they are going, or where they currently are. We illustrate each of these three basic categories, survey and classify all known forms of intragenomic conflict, and discuss the implications for organismal maladaptation and human disease.}, }
@article {pmid29080969, year = {2018}, author = {Tornero, E and Sánchez-Romera, JF and Morosoli, JJ and Vázquez, A and Gómez, &#xc1; and Ordoñana, JR}, title = {Altruistic Behavior among Twins : Willingness to Fight and Self-Sacrifice for Their Closest Relatives.}, journal = {Human nature (Hawthorne, N.Y.)}, volume = {29}, number = {1}, pages = {1-12}, pmid = {29080969}, issn = {1936-4776}, support = {19479/PI/14//Fundaci&#xf3;n S&#xe9;neca/ ; PSI2014-56680-R//Ministerio de Econom&#xed;a y Competitividad/ ; PSI2015-67754-P//Ministerio de Econom&#xed;a y Competitividad/ ; }, mesh = {Adult ; Aggression/*psychology ; *Altruism ; Female ; Humans ; Male ; *Sibling Relations ; Twins, Dizygotic/*psychology ; Twins, Monozygotic/*psychology ; }, abstract = {According to kin selection theory, indirect reproductive advantages may induce individuals to care for others with whom they share genes by common descent, and the amount of care, including self-sacrifice, will increase with the proportion of genes shared. Twins represent a natural situation in which this hypothesis can be tested. Twin pairs experience the same early environment because they were born and raised at the same time and in the same family but their genetic relatedness differs depending on zygosity. We compared the degree of willingness to fight and sacrifice for the co-twin among monozygotic (MZ) and dizygotic (DZ) pairs in a sample of 1443 same-sex and opposite-sex twins. We also analyzed the effect of the subject's gender and that of the co-twin on those altruistic behaviors. Results partly supported the postulated explanation. MZ twins (who share nearly their entire genome) were significantly more likely than DZ twins (who on average share half of their segregating genes) to self-sacrifice for their co-twins, but zygosity did not affect willingness to fight for him/her. The genders of the subject and of the co-twin, not genetic relatedness, were the best predictors of aggressive altruistic intentions.}, }
@article {pmid29073100, year = {2017}, author = {Bebbington, K and Kingma, SA and Fairfield, EA and Dugdale, HL and Komdeur, J and Spurgin, LG and Richardson, DS}, title = {Kinship and familiarity mitigate costs of social conflict between Seychelles warbler neighbors.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {43}, pages = {E9036-E9045}, pmid = {29073100}, issn = {1091-6490}, mesh = {*Aggression ; Animal Distribution ; Animals ; Ecosystem ; Female ; Genotype ; Male ; Passeriformes/*genetics/physiology ; Recognition, Psychology ; Seychelles ; *Territoriality ; }, abstract = {Because virtually all organisms compete with others in their social environment, mechanisms that reduce conflict between interacting individuals are crucial for the evolution of stable families, groups, and societies. Here, we tested whether costs of social conflict over territorial space between Seychelles warblers (Acrocephalus sechellensis) are mitigated by kin-selected (genetic relatedness) or mutualistic (social familiarity) mechanisms. By measuring longitudinal changes in individuals' body mass and telomere length, we demonstrated that the fitness costs of territoriality are driven by a complex interplay between relatedness, familiarity, local density, and sex. Physical fights were less common at territory boundaries shared between related or familiar males. In line with this, male territory owners gained mass when living next to related or familiar males and also showed less telomere attrition when living next to male kin. Importantly, these relationships were strongest in high-density areas of the population. Males also had more rapid telomere attrition when living next to unfamiliar male neighbors, but mainly when relatedness to those neighbors was also low. In contrast, neither kinship nor familiarity was linked to body mass or telomere loss in female territory owners. Our results indicate that resolving conflict over territorial space through kin-selected or mutualistic pathways can reduce both immediate energetic costs and permanent somatic damage, thus providing an important mechanism to explain fine-scale population structure and cooperation between different social units across a broad range of taxa.}, }
@article {pmid29061969, year = {2017}, author = {Kingma, SA}, title = {Direct benefits explain interspecific variation in helping behaviour among cooperatively breeding birds.}, journal = {Nature communications}, volume = {8}, number = {1}, pages = {1094}, pmid = {29061969}, issn = {2041-1723}, mesh = {Animals ; Behavior, Animal/*physiology ; Birds/*physiology ; Breeding ; Cooperative Behavior ; Helping Behavior ; Nesting Behavior/physiology ; Species Specificity ; }, abstract = {Kin selection theory provides one important explanation for seemingly altruistic helping behaviour by non-breeding subordinates in cooperative breeding animals. However, it cannot explain why helpers in many species provide energetically costly care to unrelated offspring. Here, I use comparative analyses to show that direct fitness benefits of helping others, associated with future opportunities to breed in the resident territory, are responsible for the widespread variation in helping effort (offspring food provisioning) and kin discrimination across cooperatively breeding birds. In species where prospects of territory inheritance are larger, subordinates provide more help, and, unlike subordinates that cannot inherit a territory, do not preferentially direct care towards related offspring. Thus, while kin selection can underlie helping behaviour in some species, direct benefits are much more important than currently recognised and explain why unrelated individuals provide substantial help in many bird species.}, }
@article {pmid29055381, year = {2017}, author = {Riordan, DV}, title = {Mimetic Theory and the evolutionary paradox of schizophrenia: The archetypal scapegoat hypothesis.}, journal = {Medical hypotheses}, volume = {108}, number = {}, pages = {101-107}, doi = {10.1016/j.mehy.2017.08.010}, pmid = {29055381}, issn = {1532-2777}, mesh = {*Altruism ; *Biological Evolution ; Cultural Characteristics ; Environment ; Humans ; *Interpersonal Relations ; Language ; Models, Biological ; Models, Psychological ; Religion ; Risk ; Schizophrenia/*physiopathology ; *Social Behavior ; Social Stigma ; Violence ; }, abstract = {Schizophrenia poses an evolutionary paradox, being genetically mediated yet associated with reduced fecundity. Numerous hypotheses have attempted to address this, but few describe how the schizophrenic phenotype itself might constitute an evolutionary adaptation. This paper draws on René Girard's theory on human origins, which claims that humans evolved a tendency to mimic both the desires and the behaviours of each other (mimetic theory). This would have promoted social cohesion and co-operation, but at the cost of intra-group rivalry and conflict. The mimetic dynamic would have escalated such conflicts into reciprocal internecine violence, threatening the survival of the entire group. Girard theorised that the "scapegoat mechanism" emerged, by which means such violence was curtailed by the unanimity of "all against one", thus allowing the mimetic impulse to safely evolve further, making language and complex social behaviours possible. Whereas scapegoating may have emerged in the entire population, and any member of a community could be scapegoated if necessary, this paper proposes that the scapegoat mechanism would have worked better in groups containing members who exhibited traits, recognised by all others, which singled them out as victims. Schizophrenia may be a functional adaptation, similar in evolutionary terms to altruism, in that it may have increased inclusive fitness, by providing scapegoat victims, the choice of whom was likely to be agreed upon unanimously, even during internecine conflict, thus restoring order and protecting the group from self-destruction. This evolutionary hypothesis, uses Girardian anthropology to combine the concept of the schizophrenic as religious shaman with that of the schizophrenic as scapegoat. It may help to reconcile divergent philosophical concepts of mental illness, and also help us to better understand, and thus counter, social exclusion and stigmatisation.}, }
@article {pmid29046373, year = {2017}, author = {Smith, D}, title = {O brother, where art thou? Investment in siblings for inclusive fitness benefits, not father absence, predicts earlier age at menarche.}, journal = {Biology letters}, volume = {13}, number = {10}, pages = {}, pmid = {29046373}, issn = {1744-957X}, support = {G9815508/MRC_/Medical Research Council/United Kingdom ; MC_PC_15018/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Adolescent ; Age Factors ; Child ; England ; *Fathers ; Female ; Humans ; Longitudinal Studies ; Male ; Menarche/*physiology ; *Paternal Deprivation ; *Siblings ; }, abstract = {Numerous studies have indicated that father absence is associated with earlier age at menarche, with many evolutionary theories assuming that father absence is a causal factor that accelerates reproductive development. However, an alternative interpretation suggests that offspring may reproduce earlier in the presence of half- or step-siblings as the indirect fitness benefits to investing in them are lower, relative to delaying reproduction and investing in full siblings. From this perspective, father absence may perform no causal role in facilitating the onset of menarche. Using data from the Avon Longitudinal Study of Parents and Children, I find that individuals with only half- or step-siblings reach reproductive age earlier than those with only full siblings, with no independent effect of father absence. These results suggest that inclusive fitness benefits to investing in siblings, rather than father absence, may predict variation in age at menarche. These results provide a greater understanding of the adaptive mechanisms involved in reproductive decision-making, as well as potential implications for human life-history evolution and cooperative breeding more broadly.}, }
@article {pmid29021183, year = {2017}, author = {Levin, SR and West, SA}, title = {The evolution of cooperation in simple molecular replicators.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1864}, pages = {}, pmid = {29021183}, issn = {1471-2954}, mesh = {Animals ; Bacteria/genetics ; Biological Evolution ; *Evolution, Molecular ; *Genome ; *Life History Traits ; Models, Genetic ; Social Behavior ; }, abstract = {In order for the first genomes to evolve, independent replicators had to act cooperatively, with some reducing their own replication rate to help copy others. It has been argued that limited diffusion explains this early cooperation. However, social evolution models have shown that limited diffusion on its own often does not favour cooperation. Here we model early replicators using social evolution tools. We show that: (i) replicators can be considered to be cooperating as a result of kin selection; (ii) limited diffusion on its own does not favour cooperation; and (iii) the addition of overlapping generations, probably a general trait of molecular replicators, promotes cooperation. These results suggest key life-history features in the evolution of the genome and that the same factors can favour cooperation across the entire tree of life.}, }
@article {pmid28977660, year = {2019}, author = {Gong, X and Zhang, F and Fung, HH}, title = {Are Older Adults More Willing to Donate? The Roles of Donation Form and Social Relationship.}, journal = {The journals of gerontology. Series B, Psychological sciences and social sciences}, volume = {74}, number = {3}, pages = {440-448}, doi = {10.1093/geronb/gbx099}, pmid = {28977660}, issn = {1758-5368}, mesh = {Aged ; *Altruism ; Cultural Characteristics ; Decision Making/physiology ; *Family Relations ; Female ; *Gift Giving ; Humans ; Male ; Middle Aged ; *Psychological Distance ; Social Behavior ; Young Adult ; }, abstract = {OBJECTIVES: Whether older adults are more prosocial than younger adults has been under debate. In the current study, we investigated how age differences in prosocial behaviors varied across different contextual factors, that is, donation form, kinship, and social distance.<br><br>METHODS: To achieve this purpose, 89 younger and 66 older adults took part in a hypothetical donation task in which they were asked to donate money and time to relatives and nonrelatives at various social distances.<br><br>RESULTS: The results showed that, compared to younger adults, (a) older adults donated less to nonrelatives (regardless of the donation form), but donated a similar amount (in money) or even donated more (in time) to relatives; (b) older adults displayed higher levels of kin selection (favoring relatives over nonrelatives) in both monetary and time donations; and (c) older adults showed higher levels of social discounting (favoring socially close over distant others) in monetary but not time donation.<br><br>DISCUSSION: The study underscored the importance of contextual factors in understanding age differences in prosocial behaviors such as donation.}, }
@article {pmid28957516, year = {2017}, author = {Van Cleve, J}, title = {Stags, Hawks, and Doves: Social Evolution Theory and Individual Variation in Cooperation.}, journal = {Integrative and comparative biology}, volume = {57}, number = {3}, pages = {566-579}, doi = {10.1093/icb/icx071}, pmid = {28957516}, issn = {1557-7023}, mesh = {Animals ; *Biological Evolution ; Cooperative Behavior ; *Game Theory ; Individuality ; *Social Behavior ; }, abstract = {One of the triumphs of evolutionary biology is the discovery of robust mechanisms that promote the evolution of cooperative behaviors even when cooperation reduces the fertility or survival of cooperators. These mechanisms include, kin selection, reciprocity, and direct benefits to cooperation that are often nonlinear. Though they have been extensively studied separately, investigating the joint action of these mechanisms has been more difficult. Moreover, how these mechanisms shape variation in cooperation is not well known. Such variation is crucial for understanding the evolution of behavioral syndromes and animal personality. Here, I use the tools of kin selection and evolutionary game theory to build a framework that integrates these mechanisms for pairwise social interactions. Using relatedness as a measure of the strength of kin selection, responsiveness as a measure of reciprocity, and synergy as a measure of payoff nonlinearity, I show how different combinations of these three parameters produce directional selection for or against cooperation or variation in levels of cooperation via stabilizing or diversifying selection. Moreover, each of these outcomes maps uniquely to one of four classic games from evolutionary game theory, which means that modulating relatedness, responsiveness, and synergy effectively transforms the payoff matrix from one the evolutionary game to another. Assuming that cooperation exacts a fertility cost on cooperators and provides a fertility benefit to social partners, a prisoner's dilemma game and directional selection against cooperation occur when relatedness and responsiveness are low and synergy is not too positive. Enough positive synergy in these conditions generates a stag-hunt game and diversifying selection. High levels of relatedness or responsiveness turn cooperation from a fitness cost into a fitness benefit, which produces a mutualism game and directional selection for cooperation when synergy is not too negative. Sufficiently negative synergy in this case creates a hawk-dove game and stabilizing selection for cooperation. I extend the results with relatedness and synergy to social groups and show that how group size changes the effect of relatedness and synergy on selection for cooperation depends on how the per capita benefit of cooperation changes with group size. Together, these results provide a general framework with which to generate comparative predictions that can be tested using quantitative genetic techniques and experimental techniques that manipulate investment in cooperation. These predictions will help us understand both interspecific variation in cooperation as well as within-population and within-group variation in cooperation related to behavioral syndromes.}, }
@article {pmid28957466, year = {2017}, author = {Harpur, BA and Dey, A and Albert, JR and Patel, S and Hines, HM and Hasselmann, M and Packer, L and Zayed, A}, title = {Queens and Workers Contribute Differently to Adaptive Evolution in Bumble Bees and Honey Bees.}, journal = {Genome biology and evolution}, volume = {9}, number = {9}, pages = {2395-2402}, pmid = {28957466}, issn = {1759-6653}, mesh = {*Adaptation, Physiological ; Animals ; Bees/*genetics/physiology ; *Evolution, Molecular ; Female ; Genetic Fitness ; Male ; Selection, Genetic ; *Social Behavior ; }, abstract = {Eusociality represents a major transition in evolution and is typified by cooperative brood care and reproductive division of labor between generations. In bees, this division of labor allows queens and workers to phenotypically specialize. Worker traits associated with helping are thought to be crucial to the fitness of a eusocial lineage, and recent studies of honey bees (genus Apis) have found that adaptively evolving genes often have worker-biased expression patterns. It is unclear however if worker-biased genes are disproportionately acted on by strong positive selection in all eusocial insects. We undertook a comparative population genomics study of bumble bees (Bombus) and honey bees to quantify natural selection on queen- and worker-biased genes across two levels of social complexity. Despite sharing a common eusocial ancestor, genes, and gene groups with the highest levels of positive selection were often unique within each genus, indicating that life history and the environment, but not sociality per se, drives patterns of adaptive molecular evolution. We uncovered differences in the contribution of queen- and worker-biased genes to adaptive evolution in bumble bees versus honey bees. Unlike honey bees, where worker-biased genes are enriched for signs of adaptive evolution, genes experiencing positive selection in bumble bees were predominately expressed by reproductive foundresses during the initial solitary-founding stage of colonies. Our study suggests that solitary founding is a major selective pressure and that the loss of queen totipotency may cause a change in the architecture of selective pressures upon the social insect genome.}, }
@article {pmid28954911, year = {2017}, author = {Qi, XG and Huang, K and Fang, G and Grueter, CC and Dunn, DW and Li, YL and Ji, W and Wang, XY and Wang, RT and Garber, PA and Li, BG}, title = {Male cooperation for breeding opportunities contributes to the evolution of multilevel societies.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1863}, pages = {}, pmid = {28954911}, issn = {1471-2954}, mesh = {Animals ; *Breeding ; Colobinae/genetics/*physiology ; *Cooperative Behavior ; Male ; Phylogeny ; *Sexual Behavior, Animal ; Telemetry ; }, abstract = {A small number of primate species including snub-nosed monkeys (colobines), geladas (papionins) and humans live in multilevel societies (MLSs), in which multiple one-male polygamous units (OMUs) coexist to form a band, and non-breeding males associate in bachelor groups. Phylogenetic reconstructions indicate that the papionin MLS appears to have evolved through internal fissioning of large mixed-sex groups, whereas the colobine MLS evolved through the aggregation of small, isolated OMUs. However, how agonistic males maintain tolerance under intensive competition over limited breeding opportunities remains unclear. Using a combination of behavioural analysis, satellite telemetry and genetic data, we quantified the social network of males in a bachelor group of golden snub-nosed monkeys. The results show a strong effect of kinship on social bonds among bachelors. Their interactions ranged from cooperation to agonism, and were regulated by access to mating partners. We suggest that an 'arms race' between breeding males' collective defence against usurpation attempts by bachelor males and bachelor males' aggregative offence to obtain reproductive opportunities has selected for larger group size on both sides. The results provide insight into the role that kin selection plays in shaping inter-male cohesion which facilities the evolution of multilevel societies. These findings have implications for understanding human social evolution, as male-male bonds are a hallmark of small- and large-scale human societies.}, }
@article {pmid28954904, year = {2017}, author = {Bshary, R and Raihani, NJ}, title = {Helping in humans and other animals: a fruitful interdisciplinary dialogue.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1863}, pages = {}, pmid = {28954904}, issn = {1471-2954}, mesh = {*Altruism ; Animals ; Biological Evolution ; *Cooperative Behavior ; *Helping Behavior ; Humans ; Interdisciplinary Research ; }, abstract = {Humans are arguably unique in the extent and scale of cooperation with unrelated individuals. While pairwise interactions among non-relatives occur in some non-human species, there is scant evidence of the large-scale, often unconditional prosociality that characterizes human social behaviour. Consequently, one may ask whether research on cooperation in humans can offer general insights to researchers working on similar questions in non-human species, and whether research on humans should be published in biology journals. We contend that the answer to both of these questions is yes. Most importantly, social behaviour in humans and other species operates under the same evolutionary framework. Moreover, we highlight how an open dialogue between different fields can inspire studies on humans and non-human species, leading to novel approaches and insights. Biology journals should encourage these discussions rather than drawing artificial boundaries between disciplines. Shared current and future challenges are to study helping in ecologically relevant contexts in order to correctly interpret how payoff matrices translate into inclusive fitness, and to integrate mechanisms into the hitherto largely functional theory. We can and should study human cooperation within a comparative framework in order to gain a full understanding of the evolution of helping.}, }
@article {pmid28950415, year = {2017}, author = {Ben-Shlomo, R}, title = {Invasiveness, chimerism and genetic diversity.}, journal = {Molecular ecology}, volume = {26}, number = {23}, pages = {6502-6509}, doi = {10.1111/mec.14364}, pmid = {28950415}, issn = {1365-294X}, mesh = {Adaptation, Biological/*genetics ; Animals ; Biological Evolution ; *Chimerism ; Founder Effect ; Genetic Fitness ; *Genetic Variation ; *Introduced Species ; Models, Genetic ; Urochordata/genetics ; }, abstract = {Adaptation for invasiveness should comprise the capability to exploit and prosper in a wide range of ecological conditions and is therefore expected to be associated with a certain level of genetic diversity. Paradoxically, however, invasive populations are established by only a few founders, resulting in low genetic diversity. As a conceivable way of attaining high genetic diversity and high variance of gene expression even when a small number of founders is involved in invasiveness, I suggest here chimerism, a fusion between different individuals-a common phenomenon found in numerous phyla. The composite entity offers the chimeric organism genetic flexibility and higher inclusive fitness that depends on the joint genomic fitness of the original partners. The ability to form a chimeric entity is also applied to subsequent generations, and consequently, the level of genetic diversity does not decline over generations of population establishment following invasion.}, }
@article {pmid28884795, year = {2017}, author = {McDonald, GC and Farine, DR and Foster, KR and Biernaskie, JM}, title = {Assortment and the analysis of natural selection on social traits.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {11}, pages = {2693-2702}, doi = {10.1111/evo.13365}, pmid = {28884795}, issn = {1558-5646}, support = {BB/M013995/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/L006081/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/L009587/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Birds/genetics/physiology ; Coleoptera/genetics/physiology ; Genetic Fitness ; *Models, Genetic ; *Phenotype ; *Selection, Genetic ; *Social Behavior ; }, abstract = {A central problem in evolutionary biology is to determine whether and how social interactions contribute to natural selection. A key method for phenotypic data is social selection analysis, in which fitness effects from social partners contribute to selection only when there is a correlation between the traits of individuals and their social partners (nonrandom phenotypic assortment). However, there are inconsistencies in the use of social selection that center around the measurement of phenotypic assortment. Here, we use data analysis and simulations to resolve these inconsistencies, showing that: (i) not all measures of assortment are suitable for social selection analysis; and (ii) the interpretation of assortment, and how to detect nonrandom assortment, will depend on the scale at which it is measured. We discuss links to kin selection theory and provide a practical guide for the social selection approach.}, }
@article {pmid28870603, year = {2017}, author = {Corley, M and Valeggia, C and Fernandez-Duque, E}, title = {Hormonal correlates of development and natal dispersal in wild female owl monkeys (Aotus azarae) of Argentina.}, journal = {Hormones and behavior}, volume = {96}, number = {}, pages = {42-51}, pmid = {28870603}, issn = {1095-6867}, support = {P30 AG012836/AG/NIA NIH HHS/United States ; R24 HD044964/HD/NICHD NIH HHS/United States ; }, mesh = {Animal Distribution/*physiology ; Animals ; Animals, Wild ; Aotidae/*growth &amp; development/*metabolism ; Argentina ; Feces/chemistry ; Female ; Gonadal Steroid Hormones/analysis/*metabolism ; Male ; Reproduction/physiology ; Sexual Maturation/physiology ; }, abstract = {Pair-living and socially monogamous primates typically do not reproduce before dispersing. It is currently unclear whether this reproductive suppression is due to endocrine or behavioral mechanisms. Cooperatively breeding taxa, like callitrichids, may forego reproduction in natal groups because they reap inclusive fitness benefits and/or they are avoiding inbreeding. However, neither of these benefits of delayed reproduction appear to adequately explain the lack of reproduction prior to leaving the natal group in pair-living monogamous species. In this study, we determined whether wild Azara's owl monkeys (Aotus azarae) in the Argentinean Chaco establish reproductive maturity prior to dispersing. We utilized 635 fecal extracts to characterize reproductive hormone profiles of 11 wild juvenile and subadult females using enzyme immunoassays. Subadult females showed hormone profiles indicative of ovulatory cycling and had mean PdG and E1G concentrations approximately five times higher than juveniles. Contrary to expectations from the inbreeding avoidance hypothesis, female owl monkeys do not delay puberty, but rather commence ovarian cycling while residing in their natal group. Still, subadults appear to have a period during which they experience irregular, non-conceptive cycles prior to reproducing. Commencing these irregular cycles in the natal group may allow them to develop a state of suspended readiness, which could be essential to securing a mate, while avoiding costs of ranging solitarily. Our results indicate that reproductive suppression in female owl monkeys is not due to endocrine suppression. We suggest that adults likely use behavioral mechanisms to prevent subadults from reproducing with unrelated adult males in their natal group.}, }
@article {pmid28845069, year = {2017}, author = {Engelhardt, A and Muniz, L and Perwitasari-Farajallah, D and Widdig, A}, title = {Highly Polymorphic Microsatellite Markers for the Assessment of Male Reproductive Skew and Genetic Variation in Critically Endangered Crested Macaques (Macaca nigra).}, journal = {International journal of primatology}, volume = {38}, number = {4}, pages = {672-691}, pmid = {28845069}, issn = {0164-0291}, abstract = {Genetic analyses based on noninvasively collected samples have become an important tool for evolutionary biology and conservation. Crested macaques (Macaca nigra), endemic to Sulawesi, Indonesia, are important for our understanding of primate evolution as Sulawesi macaques represent an exceptional example of primate adaptive radiation. Crested macaques are also Critically Endangered. However, to date we know very little about their genetics. The aim of our study was to find and validate microsatellite markers useful for evolutionary, conservation, and other genetic studies on wild crested macaques. Using fecal samples of 176 wild macaques living in the Tangkoko Reserve, Sulawesi, we identified 12 polymorphic microsatellite loci through cross-species polymerase chain reaction amplification with later modification of some of these primers. We tested their suitability by investigating and exploring patterns of paternity, observed heterozygosity, and evidence for inbreeding. We assigned paternity to 63 of 65 infants with high confidence. Among cases with solved paternity, we found no evidence of extragroup paternity and natal breeding. We found a relatively steep male reproductive skew B index of 0.330 ± 0.267; mean ± SD) and mean alpha paternity of 65% per year with large variation across groups and years (29-100%). Finally, we detected an excess in observed heterozygosity and no evidence of inbreeding across our three study groups, with an observed heterozygosity of 0.766 ± 0.059 and expected heterozygosity of 0.708 ± 0.059, and an inbreeding coefficient of -0.082 ± 0.035. Our results indicate that the selected markers are useful for genetic studies on wild crested macaques, and possibly also on other Sulawesi and closely related macaques. They further suggest that the Tangkoko population of crested macaques is still genetically variable despite its small size, isolation, and the species' reproductive patterns. This gives us hope that other endangered primate species living in small, isolated populations may also retain a healthy gene pool, at least in the short term.}, }
@article {pmid28841690, year = {2017}, author = {Kücklich, M and Möller, M and Marcillo, A and Einspanier, A and Weiß, BM and Birkemeyer, C and Widdig, A}, title = {Different methods for volatile sampling in mammals.}, journal = {PloS one}, volume = {12}, number = {8}, pages = {e0183440}, pmid = {28841690}, issn = {1932-6203}, mesh = {Animal Communication ; Animals ; Callithrix/*physiology ; Female ; Gas Chromatography-Mass Spectrometry ; Odorants ; Volatile Organic Compounds/*analysis ; }, abstract = {Previous studies showed that olfactory cues are important for mammalian communication. However, many specific compounds that convey information between conspecifics are still unknown. To understand mechanisms and functions of olfactory cues, olfactory signals such as volatile compounds emitted from individuals need to be assessed. Sampling of animals with and without scent glands was typically conducted using cotton swabs rubbed over the skin or fur and analysed by gas chromatography-mass spectrometry (GC-MS). However, this method has various drawbacks, including a high level of contaminations. Thus, we adapted two methods of volatile sampling from other research fields and compared them to sampling with cotton swabs. To do so we assessed the body odor of common marmosets (Callithrix jacchus) using cotton swabs, thermal desorption (TD) tubes and, alternatively, a mobile GC-MS device containing a thermal desorption trap. Overall, TD tubes comprised most compounds (N = 113), with half of those compounds being volatile (N = 52). The mobile GC-MS captured the fewest compounds (N = 35), of which all were volatile. Cotton swabs contained an intermediate number of compounds (N = 55), but very few volatiles (N = 10). Almost all compounds found with the mobile GC-MS were also captured with TD tubes (94%). Hence, we recommend TD tubes for state of the art sampling of body odor of mammals or other vertebrates, particularly for field studies, as they can be easily transported, stored and analysed with high performance instruments in the lab. Nevertheless, cotton swabs capture compounds which still may contribute to the body odor, e.g. after bacterial fermentation, while profiles from mobile GC-MS include only the most abundant volatiles of the body odor.}, }
@article {pmid28839927, year = {2017}, author = {Gardner, A}, title = {The purpose of adaptation.}, journal = {Interface focus}, volume = {7}, number = {5}, pages = {20170005}, pmid = {28839927}, issn = {2042-8898}, abstract = {A central feature of Darwin's theory of natural selection is that it explains the purpose of biological adaptation. Here, I: emphasize the scientific importance of understanding what adaptations are for, in terms of facilitating the derivation of empirically testable predictions; discuss the population genetical basis for Darwin's theory of the purpose of adaptation, with reference to Fisher's 'fundamental theorem of natural selection'; and show that a deeper understanding of the purpose of adaptation is achieved in the context of social evolution, with reference to inclusive fitness and superorganisms.}, }
@article {pmid28812668, year = {2017}, author = {Chak, STC and Duffy, JE and Hultgren, KM and Rubenstein, DR}, title = {Evolutionary transitions towards eusociality in snapping shrimps.}, journal = {Nature ecology &amp; evolution}, volume = {1}, number = {4}, pages = {96}, doi = {10.1038/s41559-017-0096}, pmid = {28812668}, issn = {2397-334X}, abstract = {Animal social organization varies from complex societies where reproduction is dominated by a single individual (eusociality) to those where reproduction is more evenly distributed among group members (communal breeding). Yet, how simple groups transition evolutionarily to more complex societies remains unclear. Competing hypotheses suggest that eusociality and communal breeding are alternative evolutionary endpoints, or that communal breeding is an intermediate stage in the transition towards eusociality. We tested these alternative hypotheses in sponge-dwelling shrimps, Synalpheus spp. Although species varied continuously in reproductive skew, they clustered into pair-forming, communal and eusocial categories based on several demographic traits. Evolutionary transition models suggested that eusocial and communal species are discrete evolutionary endpoints that evolved independently from pair-forming ancestors along alternative paths. This 'family-centred' origin of eusociality parallels observations in insects and vertebrates, reinforcing the role of kin selection in the evolution of eusociality and suggesting a general model of animal social evolution.}, }
@article {pmid28794215, year = {2017}, author = {Le Page, S and Sepil, I and Flintham, E and Pizzari, T and Carazo, P and Wigby, S}, title = {Male relatedness and familiarity are required to modulate male-induced harm to females in Drosophila.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1860}, pages = {}, pmid = {28794215}, issn = {1471-2954}, support = {BB/K014544/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Courtship ; Drosophila melanogaster/*physiology ; Female ; Male ; Reproduction ; *Sexual Behavior, Animal ; }, abstract = {Males compete over mating and fertilization, and often harm females in the process. Inclusive fitness theory predicts that increasing relatedness within groups of males may relax competition and discourage male harm of females as males gain indirect benefits. Recent studies in Drosophila melanogaster are consistent with these predictions, and have found that within-group male relatedness increases female fitness, though others have found no effects. Importantly, these studies did not fully disentangle male genetic relatedness from larval familiarity, so the extent to which modulation of harm to females is explained by male familiarity remains unclear. Here we performed a fully factorial design, isolating the effects of male relatedness and larval familiarity on female harm. While we found no differences in male courtship or aggression, there was a significant interaction between male genetic relatedness and familiarity on female reproduction and survival. Relatedness among males increased female lifespan, reproductive lifespan and overall reproductive success, but only when males were familiar. By showing that both male relatedness and larval familiarity are required to modulate female harm, these findings reconcile previous studies, shedding light on the potential role of indirect fitness effects on sexual conflict and the mechanisms underpinning kin recognition in fly populations.}, }
@article {pmid28791162, year = {2017}, author = {Birch, J}, title = {The inclusive fitness controversy: finding a way forward.}, journal = {Royal Society open science}, volume = {4}, number = {7}, pages = {170335}, pmid = {28791162}, issn = {2054-5703}, abstract = {This paper attempts to reconcile critics and defenders of inclusive fitness by constructing a synthesis that does justice to the insights of both. I argue that criticisms of the regression-based version of Hamilton's rule, although they undermine its use for predictive purposes, do not undermine its use as an organizing framework for social evolution research. I argue that the assumptions underlying the concept of inclusive fitness, conceived as a causal property of an individual organism, are unlikely to be exactly true in real populations, but they are approximately true given a specific type of weak selection that Hamilton took, on independent grounds, to be responsible for the cumulative assembly of complex adaptation. Finally, I reflect on the uses and limitations of 'design thinking' in social evolution research.}, }
@article {pmid28766161, year = {2017}, author = {Amici, F and Mimó, MC and von Borell, C and Bueno-Guerra, N}, title = {Meerkats (Suricata suricatta) fail to prosocially donate food in an experimental set-up.}, journal = {Animal cognition}, volume = {20}, number = {6}, pages = {1059-1066}, doi = {10.1007/s10071-017-1122-6}, pmid = {28766161}, issn = {1435-9456}, mesh = {Animals ; *Feeding Behavior ; Female ; Herpestidae/*psychology ; Male ; Motivation ; *Social Behavior ; Video Recording ; }, abstract = {Although humans are usually believed to be prosocial, the evolutionary origins of prosociality are largely debated. One hypothesis is that cooperative breeding has been one major precursor to the emergence of prosociality. In vertebrates, however, experimental evidence of prosociality has been mainly gathered in non-human primates. In this study, we tested the cooperative breeding hypothesis in cooperative breeding meerkats (Suricata suricatta). In particular, we tested whether meerkats take into account partners' benefits when distributing food rewards. Nine individuals were presented with two platforms baited with different food distributions (providing food to themselves, to a partner or both). In all conditions, the decision to operate the apparatus was based on the presence of food on the subject's side, and not on the possible benefits to partners. Despite being cooperative breeders, meerkats in this study failed to be prosocial, suggesting that prosociality in this species may be limited to specific contexts.}, }
@article {pmid28765001, year = {2017}, author = {Marcillo, A and Jakimovska, V and Widdig, A and Birkemeyer, C}, title = {Comparison of two common adsorption materials for thermal desorption gas chromatography - mass spectrometry of biogenic volatile organic compounds.}, journal = {Journal of chromatography. A}, volume = {1514}, number = {}, pages = {16-28}, doi = {10.1016/j.chroma.2017.07.005}, pmid = {28765001}, issn = {1873-3778}, mesh = {Adsorption ; Animals ; Gas Chromatography-Mass Spectrometry/*methods/standards ; Gases/chemistry ; Odorants/analysis ; Polymers/analysis/chemistry ; Reference Standards ; Solvents/chemistry ; Temperature ; Volatile Organic Compounds/*analysis/standards ; }, abstract = {Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatography (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for non-polar to semipolar volatiles, however, many volatiles from environmental and biological samples possess a rather polar character. Therefore, we tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (bp. 20-256°C) and different chemical classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At first, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, we tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Moreover, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture. Volatiles were analyzed in a range between 0.01-∼250ng/tube depending on the compound and material. Lower limits of quantitation were between 0.01 and 3 ng±<25% RSD (R[2]>0.9). Interestingly, we found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS analysis.}, }
@article {pmid30283644, year = {2017}, author = {Bebbington, K and Kingma, SA}, title = {No evidence that kin selection increases the honesty of begging signals in birds.}, journal = {Evolution letters}, volume = {1}, number = {3}, pages = {132-137}, pmid = {30283644}, issn = {2056-3744}, abstract = {Providing plausible mechanisms to explain variation in the honesty of information communicated through offspring begging signals is fundamental to our understanding of parent-offspring conflict and the evolution of family life. A recently published research article used comparative analyses to investigate two long-standing hypotheses that may explain the evolution of begging behavior. The results suggested that direct competition between offspring for parental resources decreases begging honesty, whereas indirect, kin-selected benefits gained through saving parental resources for the production of future siblings increase begging honesty. However, we feel that evidence for a role of kin selection in this context is still missing. We present a combination of arguments and empirical tests to outline alternative sources of interspecific variation in offspring begging levels and discuss avenues for further research that can bring us closer to a complete understanding of the evolution of offspring signaling.}, }
@article {pmid28739172, year = {2017}, author = {Thouzeau, V and Raymond, M}, title = {Emergence and maintenance of menopause in humans: A game theory model.}, journal = {Journal of theoretical biology}, volume = {430}, number = {}, pages = {229-236}, doi = {10.1016/j.jtbi.2017.07.019}, pmid = {28739172}, issn = {1095-8541}, mesh = {*Biological Evolution ; Family Characteristics ; Female ; *Game Theory ; Humans ; *Menopause ; Reproduction ; }, abstract = {Menopause, the permanent cessation of ovulation, occurs in women well before the end of their expected life span. Several adaptive hypotheses have been proposed to solve this evolutionary puzzle, each based on a possible fitness benefit derived from an early reproductive senescence, but no consensus has emerged. The construction of a game theory model allowed us to jointly study the main adaptive hypotheses in emergence and maintenance of menopause. Four classical hypotheses on the benefits of menopause were considered (decreased maternal mortality, increased grandmothering, decreased conflict over reproductive resources between older and younger females, and changes in their relatedness) plus a fifth one derived from a possible pleiotropic trade-off. Interestingly, the conditions for the emergence of menopause are more restrictive than those for its maintenance due to the social and familial changes induced by the occurrence of non-reproductive older women.}, }
@article {pmid28711317, year = {2017}, author = {Mullon, C and Lehmann, L}, title = {Invasion fitness for gene-culture co-evolution in family-structured populations and an application to cumulative culture under vertical transmission.}, journal = {Theoretical population biology}, volume = {116}, number = {}, pages = {33-46}, doi = {10.1016/j.tpb.2017.06.003}, pmid = {28711317}, issn = {1096-0325}, mesh = {Adaptation, Physiological ; *Biological Evolution ; *Cultural Characteristics ; *Cultural Evolution ; Culture ; *Genetics, Behavioral ; Humans ; *Learning ; Models, Biological ; }, abstract = {Human evolution depends on the co-evolution between genetically determined behaviors and socially transmitted information. Although vertical transmission of cultural information from parent to offspring is common in hominins, its effects on cumulative cultural evolution are not fully understood. Here, we investigate gene-culture co-evolution in a family-structured population by studying the invasion fitness of a mutant allele that influences a deterministic level of cultural information (e.g., amount of knowledge or skill) to which diploid carriers of the mutant are exposed in subsequent generations. We show that the selection gradient on such a mutant, and the concomitant level of cultural information it generates, can be evaluated analytically under the assumption that the cultural dynamic has a single attractor point, thereby making gene-culture co-evolution in family-structured populations with multigenerational effects mathematically tractable. We apply our result to study how genetically determined phenotypes of individual and social learning co-evolve with the level of adaptive information they generate under vertical transmission. We find that vertical transmission increases adaptive information due to kin selection effects, but when information is transmitted as efficiently between family members as between unrelated individuals, this increase is moderate in diploids. By contrast, we show that the way resource allocation into learning trades off with allocation into reproduction (the "learning-reproduction trade-off") significantly influences levels of adaptive information. We also show that vertical transmission prevents evolutionary branching and may therefore play a qualitative role in gene-culture co-evolutionary dynamics. More generally, our analysis of selection suggests that vertical transmission can significantly increase levels of adaptive information under the biologically plausible condition that information transmission between relatives is more efficient than between unrelated individuals.}, }
@article {pmid28699275, year = {2018}, author = {Phillips, T}, title = {The concepts of asymmetric and symmetric power can help resolve the puzzle of altruistic and cooperative behaviour.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {93}, number = {1}, pages = {457-468}, doi = {10.1111/brv.12352}, pmid = {28699275}, issn = {1469-185X}, mesh = {*Altruism ; Animals ; *Biological Evolution ; *Cooperative Behavior ; Models, Biological ; }, abstract = {Evolutionary theory predicts competition in nature yet altruistic and cooperative behaviour appears to reduce the ability to compete in order to help others compete better. This evolutionary puzzle is usually explained by kin selection where close relatives perform altruistic and cooperative acts to help each other and by reciprocity theory (i.e. direct, indirect and generalized reciprocity) among non-kin. Here, it is proposed that the concepts of asymmetry and symmetry in power and dominance are critical if we are ever to resolve the puzzle of altruism and cooperation towards non-kin. Asymmetry in power and dominance is likely to emerge under competition in nature as individuals strive to gain greater access to the scarce resources needed to survive and reproduce successfully. Yet asymmetric power presents serious problems for reciprocity theory in that a dominant individual faces a temptation to cheat in interactions with subordinates that is likely to far outweigh any individual selective benefits gained through reciprocal mechanisms. Furthermore, action taken by subordinates to deter non-reciprocation by dominants is likely to prove prohibitively costly to their fitness, making successful enforcement of reciprocal mechanisms unlikely. It is also argued here that many apparently puzzling forms of cooperation observed in nature (e.g. cooperative breeding in which unrelated subordinates help dominants to breed) might be best explained by asymmetry in power and dominance. Once it is recognized that individuals in these cooperative interactions are subject to the constraints and opportunities imposed on them by asymmetric power then they can be seen as pursuing a 'least bad' strategy to promote individual fitness - one that is nevertheless consistent with evolutionary theory. The concept of symmetric power also provides important insights. It can inhibit reciprocal mechanisms in the sense that symmetric power makes it easier for a cheat to appropriate common resources while incurring fewer penalties. Nevertheless under certain restrictive conditions, symmetric power is seen as likely to promote direct reciprocity through 'tit for tat'.}, }
@article {pmid28681487, year = {2017}, author = {Wloch-Salamon, DM and Fisher, RM and Regenberg, B}, title = {Division of labour in the yeast: Saccharomyces cerevisiae.}, journal = {Yeast (Chichester, England)}, volume = {34}, number = {10}, pages = {399-406}, doi = {10.1002/yea.3241}, pmid = {28681487}, issn = {1097-0061}, mesh = {Adaptation, Physiological ; Apoptosis ; Biofilms/growth &amp; development ; Biological Evolution ; Phenotype ; Resting Phase, Cell Cycle ; Saccharomyces cerevisiae/genetics/*physiology ; }, abstract = {Division of labour between different specialized cell types is a central part of how we describe complexity in multicellular organisms. However, it is increasingly being recognized that division of labour also plays an important role in the lives of predominantly unicellular organisms. Saccharomyces cerevisiae displays several phenotypes that could be considered a division of labour, including quiescence, apoptosis and biofilm formation, but they have not been explicitly treated as such. We discuss each of these examples, using a definition of division of labour that involves phenotypic variation between cells within a population, cooperation between cells performing different tasks and maximization of the inclusive fitness of all cells involved. We then propose future research directions and possible experimental tests using S. cerevisiae as a model organism for understanding the genetic mechanisms and selective pressures that can lead to the evolution of the very first stages of a division of labour. Copyright © 2017 John Wiley &amp; Sons, Ltd.}, }
@article {pmid28672203, year = {2017}, author = {Caniglia, G}, title = {"How complex and even perverse the real world can be": W.D. Hamilton's early work on social wasps (1964-1968).}, journal = {Studies in history and philosophy of biological and biomedical sciences}, volume = {64}, number = {}, pages = {41-52}, doi = {10.1016/j.shpsc.2017.06.005}, pmid = {28672203}, issn = {1879-2499}, mesh = {Animals ; Biological Evolution ; *Selection, Genetic ; *Social Behavior ; *Wasps ; }, abstract = {William D. Hamilton's name is often connected to important theoretical accomplishments, from the theory of inclusive fitness and kin selection to the so-called Hamilton's rule and the haplodiploidy hypothesis. This article asks: How did Hamilton attempt to test his theory and hypothesis against the complexity of the biological world? The article reconstructs Hamilton's empirical work with social wasps between 1963 and 1968, the years before and after the publication of the groundbreaking "The Genetical Evolution of Social Behavior" in 1964. It points out the centrality of Hamilton's work on wasps and shows how the British scientist attempted to test theories and hypotheses with naturalistic, developmental, and physiological observations as well as, at times, with experimental manipulations. The article offers a new perspective on the history of the scientific understanding of the evolution of social behavior. In contrast to existing narratives, this perspective emphasizes the importance of empirical work-e.g. natural history, physiology, comparative anatomy-which is often obscured by a nearly exclusive focus on theoretical developments in this field.}, }
@article {pmid28659767, year = {2017}, author = {Couto, A and Mitra, A and Thiéry, D and Marion-Poll, F and Sandoz, JC}, title = {Hornets Have It: A Conserved Olfactory Subsystem for Social Recognition in Hymenoptera?.}, journal = {Frontiers in neuroanatomy}, volume = {11}, number = {}, pages = {48}, pmid = {28659767}, issn = {1662-5129}, abstract = {Eusocial Hymenoptera colonies are characterized by the presence of altruistic individuals, which rear their siblings instead of their own offspring. In the course of evolution, such sterile castes are thought to have emerged through the process of kin selection, altruistic traits being transmitted to following generation if they benefit relatives. By allowing kinship recognition, the detection of cuticular hydrocarbons (CHCs) might be instrumental for kin selection. In carpenter ants, a female-specific olfactory subsystem processes CHC information through antennal detection by basiconic sensilla. It is still unclear if other families of eusocial Hymenoptera use the same subsystem for sensing CHCs. Here, we examined the existence of such a subsystem in Vespidae (using the hornet Vespa velutina), a family in which eusociality emerged independently of ants. The antennae of both males and female hornets contain large basiconic sensilla. Sensory neurons from the large basiconic sensilla exclusively project to a conspicuous cluster of small glomeruli in the antennal lobe, with anatomical and immunoreactive features that are strikingly similar to those of the ant CHC-sensitive subsystem. Extracellular electrophysiological recordings further show that sensory neurons within hornet basiconic sensilla preferentially respond to CHCs. Although this subsystem is not female-specific in hornets, the observed similarities with the olfactory system of ants are striking. They suggest that the basiconic sensilla subsystem could be an ancestral trait, which may have played a key role in the advent of eusociality in these hymenopteran families by allowing kin recognition and the production of altruistic behaviors toward relatives.}, }
@article {pmid28622934, year = {2017}, author = {Kessler, SE and Bonnell, TR and Byrne, RW and Chapman, CA}, title = {Selection to outsmart the germs: The evolution of disease recognition and social cognition.}, journal = {Journal of human evolution}, volume = {108}, number = {}, pages = {92-109}, doi = {10.1016/j.jhevol.2017.02.009}, pmid = {28622934}, issn = {1095-8606}, mesh = {*Biological Evolution ; *Cognition ; *Delivery of Health Care ; Disease Transmission, Infectious/*prevention &amp; control ; Family ; Humans ; *Social Behavior ; }, abstract = {The emergence of providing care to diseased conspecifics must have been a turning point during the evolution of hominin sociality. On a population level, care may have minimized the costs of socially transmitted diseases at a time of increasing social complexity, although individual care-givers probably incurred increased transmission risks. We propose that care-giving likely originated within kin networks, where the costs may have been balanced by fitness increases obtained through caring for ill kin. We test a novel hypothesis of hominin cognitive evolution in which disease may have selected for the cognitive ability to recognize when a conspecific is infected. Because diseases may produce symptoms that are likely detectable via the perceptual-cognitive pathways integral to social cognition, we suggest that disease recognition and social cognition may have evolved together. Using agent-based modeling, we test 1) under what conditions disease can select for increasing disease recognition and care-giving among kin, 2) whether providing care produces greater selection for cognition than an avoidance strategy, and 3) whether care-giving alters the progression of the disease through the population. The greatest selection was produced by diseases with lower risks to the care-giver and prevalences low enough not to disrupt the kin networks. When care-giving and avoidance strategies were compared, only care-giving reduced the severity of the disease outbreaks and subsequent population crashes. The greatest selection for increased cognitive abilities occurred early in the model runs when the outbreaks and population crashes were most severe. Therefore, over the course of human evolution, repeated introductions of novel diseases into naïve populations could have produced sustained selection for increased disease recognition and care-giving behavior, leading to the evolution of increased cognition, social complexity, and, eventually, medical care in humans. Finally, we lay out predictions derived from our disease recognition hypothesis that we encourage paleoanthropologists, bioarchaeologists, primatologists, and paleogeneticists to test.}, }
@article {pmid28596113, year = {2017}, author = {Wild, G and Korb, J}, title = {Evolution of delayed dispersal and subsequent emergence of helping, with implications for cooperative breeding.}, journal = {Journal of theoretical biology}, volume = {427}, number = {}, pages = {53-64}, doi = {10.1016/j.jtbi.2017.05.038}, pmid = {28596113}, issn = {1095-8541}, mesh = {Animals ; *Biological Evolution ; *Breeding ; Models, Biological ; }, abstract = {Cooperative breeding occurs when individuals help raise the offspring of others. It is widely accepted that help displayed by cooperative breeders emerged only after individuals' tendency to delay dispersal had become established. We use this idea as a basis for two inclusive-fitness models: one for the evolution of delayed dispersal, and a second for the subsequent emergence of helpful behavior exhibited by non-breeding individuals. We focus on a territorial species in a saturated environment, and allow territories to be inherited by non-breeding individuals who have delayed dispersal. Our first model predicts that increased survivorship and increased fecundity both provide an incentive to non-breeding individuals to delay dispersal, and stay near their natal territory for some period of time. Predictions from the first model can be well understood by ignoring complications arising from competition among relatives. Our second model shows that effects on relatives play a primary role in the advantage of helping. In addition, the second model predicts that increased survivorship and fecundity promote the emergence of help. Together, our models lead us to conclude that the emergence of cooperative-breeding systems is made easier by life-history features associated with high survivorship and fecundity. We discuss the implications of our conclusions for life-history-based hypotheses of cooperative breeding and social evolution.}, }
@article {pmid28512224, year = {2017}, author = {Nowak, MA and McAvoy, A and Allen, B and Wilson, EO}, title = {The general form of Hamilton's rule makes no predictions and cannot be tested empirically.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {22}, pages = {5665-5670}, pmid = {28512224}, issn = {1091-6490}, abstract = {Hamilton's rule asserts that a trait is favored by natural selection if the benefit to others, [Formula: see text], multiplied by relatedness, [Formula: see text], exceeds the cost to self, [Formula: see text] Specifically, Hamilton's rule states that the change in average trait value in a population is proportional to [Formula: see text] This rule is commonly believed to be a natural law making important predictions in biology, and its influence has spread from evolutionary biology to other fields including the social sciences. Whereas many feel that Hamilton's rule provides valuable intuition, there is disagreement even among experts as to how the quantities [Formula: see text], [Formula: see text], and [Formula: see text] should be defined for a given system. Here, we investigate a widely endorsed formulation of Hamilton's rule, which is said to be as general as natural selection itself. We show that, in this formulation, Hamilton's rule does not make predictions and cannot be tested empirically. It turns out that the parameters [Formula: see text] and [Formula: see text] depend on the change in average trait value and therefore cannot predict that change. In this formulation, which has been called "exact and general" by its proponents, Hamilton's rule can "predict" only the data that have already been given.}, }
@article {pmid28508537, year = {2018}, author = {Boomsma, JJ and Gawne, R}, title = {Superorganismality and caste differentiation as points of no return: how the major evolutionary transitions were lost in translation.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {93}, number = {1}, pages = {28-54}, doi = {10.1111/brv.12330}, pmid = {28508537}, issn = {1469-185X}, mesh = {Animals ; *Behavior, Animal ; *Biological Evolution ; Insecta/*genetics/*physiology ; Selection, Genetic ; *Social Behavior ; }, abstract = {More than a century ago, William Morton Wheeler proposed that social insect colonies can be regarded as superorganisms when they have morphologically differentiated reproductive and nursing castes that are analogous to the metazoan germ-line and soma. Following the rise of sociobiology in the 1970s, Wheeler's insights were largely neglected, and we were left with multiple new superorganism concepts that are mutually inconsistent and uninformative on how superorganismality originated. These difficulties can be traced to the broadened sociobiological concept of eusociality, which denies that physical queen-worker caste differentiation is a universal hallmark of superorganismal colonies. Unlike early evolutionary naturalists and geneticists such as Weismann, Huxley, Fisher and Haldane, who set out to explain the acquisition of an unmated worker caste, the goal of sociobiology was to understand the evolution of eusociality, a broad-brush convenience category that covers most forms of cooperative breeding. By lumping a diverse spectrum of social systems into a single category, and drawing attention away from the evolution of distinct quantifiable traits, the sociobiological tradition has impeded straightforward connections between inclusive fitness theory and the major evolutionary transitions paradigm for understanding irreversible shifts to higher organizational complexity. We evaluate the history by which these inconsistencies accumulated, develop a common-cause approach for understanding the origins of all major transitions in eukaryote hierarchical complexity, and use Hamilton's rule to argue that they are directly comparable. We show that only Wheeler's original definition of superorganismality can be unambiguously linked to irreversible evolutionary transitions from context-dependent reproductive altruism to unconditional differentiation of permanently unmated castes in the ants, corbiculate bees, vespine wasps and higher termites. We argue that strictly monogamous parents were a necessary, albeit not sufficient condition for all transitions to superorganismality, analogous to single-zygote bottlenecking being a necessary but not sufficient condition for the convergent origins of complex soma across multicellular eukaryotes. We infer that conflict reduction was not a necessary condition for the origin of any of these major transitions, and conclude that controversies over the status of inclusive fitness theory primarily emanate from the arbitrarily defined sociobiological concepts of superorganismality and eusociality, not from the theory itself.}, }
@article {pmid28503187, year = {2017}, author = {Lee, CC and Nakao, H and Tseng, SP and Hsu, HW and Lin, GL and Tay, JW and Billen, J and Ito, F and Lee, CY and Lin, CC and Yang, CS}, title = {Worker reproduction of the invasive yellow crazy ant Anoplolepis gracilipes.}, journal = {Frontiers in zoology}, volume = {14}, number = {}, pages = {24}, pmid = {28503187}, issn = {1742-9994}, abstract = {BACKGROUND: Reproductive division of labor is one of the key features of social insects. Queens are adapted for reproduction while workers are adapted for foraging and colony maintenance. In many species, however, workers retain functional ovaries and can lay unfertilized male eggs or trophic eggs. Here we report for the first time on the occurrence of physogastric workers and apparent worker reproduction in the invasive yellow crazy ant Anoplolepis gracilipes (Fr. Smith). We further examined the reproductive potential and nutritional role of physogastric workers through multidisciplinary approaches including morphological characterization, laboratory manipulation, genetic analysis and behavioral observation.<br><br>RESULTS: Egg production with two types of eggs, namely reproductive and trophic eggs, by physogastric workers was found. The reproductive egg was confirmed to be haploid and male-destined, suggesting that the workers produced males via arrhenotokous parthenogenesis as no spermatheca was discovered. Detailed observations suggested that larvae were&#xa0;mainly fed with trophic eggs. Along with consumption of trophic eggs by queens and other castes as part of their diet, the vital role of physogastric workers as "trophic specialist" is confirmed.<br><br>CONCLUSION: We propose that adaptive advantages derived from worker reproduction for A. gracilipes may include 1) trophic eggs provisioned by physogastric workers likely assist colonies of A. gracilipes in overcoming unfavorable conditions such as paucity of food during critical founding stage; 2) worker-produced males are fertile and thus might offer an inclusive fitness advantage for the doomed orphaned colony.}, }
@article {pmid28487486, year = {2017}, author = {Dugatkin, LA}, title = {Long reach of inclusive fitness.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {20}, pages = {5067-5068}, pmid = {28487486}, issn = {1091-6490}, mesh = {Biological Evolution ; *Genetic Fitness ; Models, Genetic ; *Selection, Genetic ; }, }
@article {pmid28469021, year = {2017}, author = {Cornioley, T and Jenouvrier, S and Börger, L and Weimerskirch, H and Ozgul, A}, title = {Fathers matter: male body mass affects life-history traits in a size-dimorphic seabird.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1854}, pages = {}, pmid = {28469021}, issn = {1471-2954}, mesh = {Animals ; Birds/*physiology ; *Body Size ; Climate Change ; Fathers ; Female ; Male ; Population Dynamics ; Reproduction ; *Sex Characteristics ; }, abstract = {One of the predicted consequences of climate change is a shift in body mass distributions within animal populations. Yet body mass, an important component of the physiological state of an organism, can affect key life-history traits and consequently population dynamics. Over the past decades, the wandering albatross-a pelagic seabird providing bi-parental care with marked sexual size dimorphism-has exhibited an increase in average body mass and breeding success in parallel with experiencing increasing wind speeds. To assess the impact of these changes, we examined how body mass affects five key life-history traits at the individual level: adult survival, breeding probability, breeding success, chick mass and juvenile survival. We found that male mass impacted all traits examined except breeding probability, whereas female mass affected none. Adult male survival increased with increasing mass. Increasing adult male mass increased breeding success and mass of sons but not of daughters. Juvenile male survival increased with their chick mass. These results suggest that a higher investment in sons by fathers can increase their inclusive fitness, which is not the case for daughters. Our study highlights sex-specific differences in the effect of body mass on the life history of a monogamous species with bi-parental care.}, }
@article {pmid28469015, year = {2017}, author = {Vitikainen, EIK and Marshall, HH and Thompson, FJ and Sanderson, JL and Bell, MBV and Gilchrist, JS and Hodge, SJ and Nichols, HJ and Cant, MA}, title = {Biased escorts: offspring sex, not relatedness explains alloparental care patterns in a cooperative breeder.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1854}, pages = {}, pmid = {28469015}, issn = {1471-2954}, mesh = {Animals ; *Cooperative Behavior ; Female ; *Helping Behavior ; Herpestidae/*physiology ; Male ; }, abstract = {Kin selection theory predicts that animals should direct costly care where inclusive fitness gains are highest. Individuals may achieve this by directing care at closer relatives, yet evidence for such discrimination in vertebrates is equivocal. We investigated patterns of cooperative care in banded mongooses, where communal litters are raised by adult 'escorts' who form exclusive caring relationships with individual pups. We found no evidence that escorts and pups assort by parentage or relatedness. However, the time males spent escorting increased with increasing relatedness to the other group members, and to the pup they had paired with. Thus, we found no effect of relatedness in partner choice, but (in males) increasing helping effort with relatedness once partner choices had been made. Unexpectedly, the results showed clear assortment by sex, with female carers being more likely to tend to female pups, and male carers to male pups. This sex-specific assortment in helping behaviour has potential lifelong impacts on individual development and may impact the future size and composition of natal groups and dispersing cohorts. Where relatedness between helpers and recipients is already high, individuals may be better off choosing partners using other predictors of the costs and benefits of cooperation, without the need for possibly costly within-group kin discrimination.}, }
@article {pmid30283638, year = {2017}, author = {O'Brien, EK and Wolf, JB}, title = {The coadaptation theory for genomic imprinting.}, journal = {Evolution letters}, volume = {1}, number = {1}, pages = {49-59}, pmid = {30283638}, issn = {2056-3744}, abstract = {Imprinted genes are peculiar in that expression of the two copies differs depending on whether the copy was maternally or paternally inherited. The discovery of this striking pattern of gene expression inspired myriad evolutionary theories, the most successful of which identify scenarios that create an asymmetry between the maternally and paternally inherited gene copies that favors silencing of one of the copies. Most notably, imprinting can evolve when gene dosage affects kin interactions (typically involving conflict) or when silencing enhances coadaptation by coordinating traits expressed by interacting kin. Although we have a well-established theory for the former process (the "Kinship Theory"), the coadaptation process has only been explored for the specific case of interactions between mothers and offspring. Here, we fill this critical gap in our understanding by developing a general "Coadaptation Theory" that explains how imprinting can evolve to coordinate interactions between all types of relatives. Using a simple model in which fitness of an individual is determined by an interaction between its own phenotype (and hence genotype) and that of its social partner(s), we find that when the relatedness of interactants differs through their maternally versus paternally inherited gene copies, then selection favors expression of the allele through which relatedness is higher. The predictions of this Coadaptation Theory potentially apply whenever a gene underlies traits that mediate the outcome of conspecific interactions, regardless of their mechanism or the type of organism, and therefore provide a potential explanation for enigmatic patterns of imprinting, including those underlying adult traits. By providing simple testable predictions that often directly contrast with those derived from alternative theories, our model should play an important role in consolidating our understanding of the evolution of imprinting across genes and species, which will ultimately provide crucial insights into imprinted gene function and dysfunction.}, }
@article {pmid28439031, year = {2017}, author = {Thompson, FJ and Cant, MA and Marshall, HH and Vitikainen, EIK and Sanderson, JL and Nichols, HJ and Gilchrist, JS and Bell, MBV and Young, AJ and Hodge, SJ and Johnstone, RA}, title = {Explaining negative kin discrimination in a cooperative mammal society.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {20}, pages = {5207-5212}, pmid = {28439031}, issn = {1091-6490}, support = {BB/H022716/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Aggression/psychology ; Animals ; Behavior, Animal ; *Conflict, Psychological ; *Cooperative Behavior ; Dominance-Subordination ; Family/*psychology ; Female ; Game Theory ; Herpestidae/*psychology ; Inbreeding ; Male ; Reproduction ; Social Behavior ; }, abstract = {Kin selection theory predicts that, where kin discrimination is possible, animals should typically act more favorably toward closer genetic relatives and direct aggression toward less closely related individuals. Contrary to this prediction, we present data from an 18-y study of wild banded mongooses, Mungos mungo, showing that females that are more closely related to dominant individuals are specifically targeted for forcible eviction from the group, often suffering severe injury, and sometimes death, as a result. This pattern cannot be explained by inbreeding avoidance or as a response to more intense local competition among kin. Instead, we use game theory to show that such negative kin discrimination can be explained by selection for unrelated targets to invest more effort in resisting eviction. Consistent with our model, negative kin discrimination is restricted to eviction attempts of older females capable of resistance; dominants exhibit no kin discrimination when attempting to evict younger females, nor do they discriminate between more closely or less closely related young when carrying out infanticidal attacks on vulnerable infants who cannot defend themselves. We suggest that in contexts where recipients of selfish acts are capable of resistance, the usual prediction of positive kin discrimination can be reversed. Kin selection theory, as an explanation for social behavior, can benefit from much greater exploration of sequential social interactions.}, }
@article {pmid28435860, year = {2017}, author = {Wang, Z and Jusup, M and Wang, RW and Shi, L and Iwasa, Y and Moreno, Y and Kurths, J}, title = {Onymity promotes cooperation in social dilemma experiments.}, journal = {Science advances}, volume = {3}, number = {3}, pages = {e1601444}, pmid = {28435860}, issn = {2375-2548}, abstract = {One of the most elusive scientific challenges for over 150 years has been to explain why cooperation survives despite being a seemingly inferior strategy from an evolutionary point of view. Over the years, various theoretical scenarios aimed at solving the evolutionary puzzle of cooperation have been proposed, eventually identifying several cooperation-promoting mechanisms: kin selection, direct reciprocity, indirect reciprocity, network reciprocity, and group selection. We report the results of repeated Prisoner's Dilemma experiments with anonymous and onymous pairwise interactions among individuals. We find that onymity significantly increases the frequency of cooperation and the median payoff per round relative to anonymity. Furthermore, we also show that the correlation between players' ranks and the usage of strategies (cooperation, defection, or punishment) underwent a fundamental shift, whereby more prosocial actions are rewarded with a better ranking under onymity. Our findings prove that reducing anonymity is a valid promoter of cooperation, leading to higher payoffs for cooperators and thus suppressing an incentive-anonymity-that would ultimately favor defection.}, }
@article {pmid28419349, year = {2017}, author = {Warner, MR and Mikheyev, AS and Linksvayer, TA}, title = {Genomic Signature of Kin Selection in an Ant with Obligately Sterile Workers.}, journal = {Molecular biology and evolution}, volume = {34}, number = {7}, pages = {1780-1787}, pmid = {28419349}, issn = {1537-1719}, mesh = {Animals ; Ants/*genetics ; Behavior, Animal ; Biological Evolution ; Evolution, Molecular ; Family ; Genetics, Population/methods ; Genomics ; Infertility/genetics ; Metagenomics/methods ; Phenotype ; Reproduction/genetics ; Selection, Genetic/*genetics ; Social Behavior ; }, abstract = {Kin selection is thought to drive the evolution of cooperation and conflict, but the specific genes and genome-wide patterns shaped by kin selection are unknown. We identified thousands of genes associated with the sterile ant worker caste, the archetype of an altruistic phenotype shaped by kin selection, and then used population and comparative genomic approaches to study patterns of molecular evolution at these genes. Consistent with population genetic theoretical predictions, worker-upregulated genes experienced reduced selection compared with genes upregulated in reproductive castes. Worker-upregulated genes included more taxonomically restricted genes, indicating that the worker caste has recruited more novel genes, yet these genes also experienced reduced selection. Our study identifies a putative genomic signature of kin selection and helps to integrate emerging sociogenomic data with longstanding social evolution theory.}, }
@article {pmid28417004, year = {2017}, author = {Jackson, CR and Groom, RJ and Jordan, NR and McNutt, JW}, title = {The effect of relatedness and pack size on territory overlap in African wild dogs.}, journal = {Movement ecology}, volume = {5}, number = {}, pages = {10}, pmid = {28417004}, issn = {2051-3933}, abstract = {BACKGROUND: Spacing patterns mediate competitive interactions between conspecifics, ultimately increasing fitness. The degree of territorial overlap between neighbouring African wild dog (Lycaon pictus) packs varies greatly, yet the role of factors potentially affecting the degree of overlap, such as relatedness and pack size, remain unclear. We used movement data from 21 wild dog packs to calculate the extent of territory overlap (20 dyads).<br><br>RESULTS: On average, unrelated neighbouring packs had low levels of overlap restricted to the peripheral regions of their 95% utilisation kernels. Related neighbours had significantly greater levels of peripheral overlap. Only one unrelated dyad included overlap between 75%-75% kernels, but no 50%-50% kernels overlapped. However, eight of 12 related dyads overlapped between their respective 75% kernels and six between the frequented 50% kernels. Overlap between these more frequented kernels confers a heightened likelihood of encounter, as the mean utilisation intensity per unit area within the 50% kernels was 4.93 times greater than in the 95% kernels, and 2.34 times greater than in the 75% kernels. Related packs spent significantly more time in their 95% kernel overlap zones than did unrelated packs. Pack size appeared to have little effect on overlap between related dyads, yet among unrelated neighbours larger packs tended to overlap more onto smaller packs' territories. However, the true effect is unclear given that the model's confidence intervals overlapped zero.<br><br>CONCLUSIONS: Evidence suggests that costly intraspecific aggression is greatly reduced between related packs. Consequently, the tendency for dispersing individuals to establish territories alongside relatives, where intensively utilised portions of ranges regularly overlap, may extend kin selection and inclusive fitness benefits from the intra-pack to inter-pack level. This natural spacing system can affect survival parameters and the carrying capacity of protected areas, having important management implications for intensively managed populations of this endangered species.}, }
@article {pmid28410027, year = {2017}, author = {Kuijper, B and Johnstone, RA}, title = {How Sex-Biased Dispersal Affects Sexual Conflict over Care.}, journal = {The American naturalist}, volume = {189}, number = {5}, pages = {501-514}, doi = {10.1086/691330}, pmid = {28410027}, issn = {1537-5323}, mesh = {*Animal Distribution ; Animals ; *Conflict, Psychological ; Female ; Male ; *Maternal Behavior ; Models, Biological ; *Paternal Behavior ; Reproduction ; Sex Factors ; }, abstract = {Existing models of parental investment have mainly focused on interactions at the level of the family and have paid much less attention to the impact of population-level processes. Here we extend classical models of parental care to assess the impact of population structure and limited dispersal. We find that sex differences in dispersal substantially affect the amount of care provided by each parent, with the more philopatric sex providing the majority of care to young. This effect is most pronounced in highly viscous populations: in such cases, when classical models would predict stable biparental care, inclusion of a modest sex difference in dispersal leads to uniparental care by the philopatric sex. In addition, mating skew also affects sex differences in parental investment, with the more numerous sex providing most of the care. However, the effect of mating skew holds only when parents care for their own offspring. When individuals breed communally, we recover the previous finding that the more philopatric sex provides most of the care even when it is the rarer sex. We conclude that sex-biased dispersal is likely to be an important yet currently overlooked driver of sex differences in parental care.}, }
@article {pmid28360453, year = {2017}, author = {Ruiz-Lambides, AV and Weiß, BM and Kulik, L and Stephens, C and Mundry, R and Widdig, A}, title = {Long-term analysis on the variance of extra-group paternities in rhesus macaques.}, journal = {Behavioral ecology and sociobiology}, volume = {71}, number = {4}, pages = {67}, pmid = {28360453}, issn = {0340-5443}, support = {P40 OD012217/OD/NIH HHS/United States ; }, abstract = {ABSTRACT: Extra-group paternity (EGP) has been described in various mammalian species; however, little is known about which factors contribute to the variation in EGP, as the majority of studies were restricted in time and the number of groups considered. Using longitudinal demographic and genetic data, we aim to investigate which factors predict rates of EGP in the free-ranging rhesus macaque population of Cayo Santiago, Puerto Rico (USA). Of the 1649 infants considered which were born into six social groups over 9 years, we identified an average of 16% of infants resulting from EGPs. We tested the influence of group size, breeding group sex ratio, female reproductive synchrony, and group instability on the occurrence of EGPs. Our results suggest a tendency for EGPs to increase as the proportion of females increased in larger groups, but no such effect in smaller groups. Furthermore, as group instability and female reproductive synchrony decreased, the number of EGPs tended to increase. Our results support the hypothesis that group structure affects the occurrence of EGPs, which might be mediated by male mating opportunities, male monopolization potential, and/or female choice.<br><br>SIGNIFICANCE STATEMENT: In several species, both sexes seek alternative reproductive strategies to enhance their reproductive success. For instance, females may pursue EGPs to potentially increase genetic compatibility with males, or males may seek EGPs to improve their mating opportunities. Our longitudinal analysis, including demographic and genetic data over 9&#xa0;years of six social groups of rhesus macaques, revealed high variation in the occurrence of EGPs across groups and years, and this variation tended to depend on group characteristics such as breeding group size, sex ratio, female synchrony, and group instability. The data suggest that group structure affects the number of EGPs in this group-living primate. Our results show that EGPs can affect the distribution of paternity within social groups and should be taken into account when assessing reproductive success.}, }
@article {pmid28345048, year = {2017}, author = {Łukasiewicz, A and Szubert-Kruszyńska, A and Radwan, J}, title = {Kin selection promotes female productivity and cooperation between the sexes.}, journal = {Science advances}, volume = {3}, number = {3}, pages = {e1602262}, pmid = {28345048}, issn = {2375-2548}, mesh = {Acaridae/*genetics ; Animals ; *Biological Evolution ; Female ; Male ; *Models, Biological ; *Quantitative Trait, Heritable ; Reproduction/physiology ; *Selection, Genetic ; }, abstract = {Hamilton's theory of kin selection explains the evolution of costly traits that benefit other individuals by highlighting the fact that passing genes to offspring is not the only way of increasing the representation of those genes in subsequent generations: Genes are also shared with other classes of relatives. Consequently, any heritable trait that affects fitness of relatives should respond to kin selection. We tested this core prediction of kin selection theory by letting bulb mites (Rhizoglyphus robini) evolve in populations structured into groups of relatives or nonrelatives during the reproductive phase of the life cycle. In accordance with predictions derived from kin selection theory, we found that evolution in groups of relatives resulted in increased female reproductive output. This increase at least partly results from the evolution of male traits that elevate their partners' fecundity. Our results highlight the power and universality of kin selection.}, }
@article {pmid28328991, year = {2017}, author = {Dušek, A and Bartoš, L and Sedláček, F}, title = {Pre-breeding food restriction promotes the optimization of parental investment in house mice, Mus musculus.}, journal = {PloS one}, volume = {12}, number = {3}, pages = {e0173985}, pmid = {28328991}, issn = {1932-6203}, mesh = {Animals ; Body Weight/physiology ; Breeding/methods ; Female ; Food ; Lactation/physiology ; Litter Size/physiology ; Mice ; Mice, Inbred ICR ; Parents ; Pregnancy ; Reproduction/*physiology ; Weaning ; }, abstract = {Litter size is one of the most reliable state-dependent life-history traits that indicate parental investment in polytocous (litter-bearing) mammals. The tendency to optimize litter size typically increases with decreasing availability of resources during the period of parental investment. To determine whether this tactic is also influenced by resource limitations prior to reproduction, we examined the effect of experimental, pre-breeding food restriction on the optimization of parental investment in lactating mice. First, we investigated the optimization of litter size in 65 experimental and 72 control families (mothers and their dependent offspring). Further, we evaluated pre-weaning offspring mortality, and the relationships between maternal and offspring condition (body weight), as well as offspring mortality, in 24 experimental and 19 control families with litter reduction (the death of one or more offspring). Assuming that pre-breeding food restriction would signal unpredictable food availability, we hypothesized that the optimization of parental investment would be more effective in the experimental rather than in the control mice. In comparison to the controls, the experimental mice produced larger litters and had a more selective (size-dependent) offspring mortality and thus lower litter reduction (the proportion of offspring deaths). Selective litter reduction helped the experimental mothers to maintain their own optimum condition, thereby improving the condition and, indirectly, the survival of their remaining offspring. Hence, pre-breeding resource limitations may have facilitated the mice to optimize their inclusive fitness. On the other hand, in the control females, the absence of environmental cues indicating a risky environment led to "maternal optimism" (overemphasizing good conditions at the time of breeding), which resulted in the production of litters of super-optimal size and consequently higher reproductive costs during lactation, including higher offspring mortality. Our study therefore provides the first evidence that pre-breeding food restriction promotes the optimization of parental investment, including offspring number and developmental success.}, }
@article {pmid28322868, year = {2017}, author = {Ohtsuki, H and Wakano, JY and Kobayashi, Y}, title = {Inclusive fitness analysis of cumulative cultural evolution in an island-structured population.}, journal = {Theoretical population biology}, volume = {115}, number = {}, pages = {13-23}, doi = {10.1016/j.tpb.2017.03.001}, pmid = {28322868}, issn = {1096-0325}, mesh = {*Biological Evolution ; *Cultural Evolution ; *Genetic Fitness ; Humans ; Learning ; Reproduction ; }, abstract = {The success of humans on the globe is largely supported by our cultural excellence. Our culture is cumulative, meaning that it is improved from generation to generation. Previous works have revealed that two modes of learning, individual learning and social learning, play pivotal roles in the accumulation of culture. However, under the trade-off between learning and reproduction, one's investment into learning is easily exploited by those who copy the knowledge of skillful individuals and selfishly invest more efforts in reproduction. It has been shown that in order to prevent such a breakdown, the rate of vertical transmission (i.e. transmission from parents to their offspring) of culture must be unrealistically close to one. Here we investigate what if the population is spatially structured. In particular, we hypothesize that spatial structure should favor highly cumulative culture through endogenously arising high kinship. We employ Wright's island model and assume that cultural transmission occurs within a local island. Our inclusive fitness analysis reveals combined effects of direct fitness of the actor, indirect fitness through relatives in the current generation, and indirect fitness through relatives in future generations. The magnitude of those indirect benefits is measured by intergenerational coefficients of genetic relatedness. Our result suggests that the introduction of spatial structure raises the stationary level of culture in the population, but that the extent of its improvement compared with a well-mixed population is marginal unless spatial localization is extreme. Overall, our model implies that we need an alternative mechanism to explain highly cumulative culture of modern humans.}, }
@article {pmid28298744, year = {2017}, author = {Welch, JJ}, title = {What's wrong with evolutionary biology?.}, journal = {Biology &amp; philosophy}, volume = {32}, number = {2}, pages = {263-279}, pmid = {28298744}, issn = {0169-3867}, abstract = {There have been periodic claims that evolutionary biology needs urgent reform, and this article tries to account for the volume and persistence of this discontent. It is argued that a few inescapable properties of the field make it prone to criticisms of predictable kinds, whether or not the criticisms have any merit. For example, the variety of living things and the complexity of evolution make it easy to generate data that seem revolutionary (e.g. exceptions to well-established generalizations, or neglected factors in evolution), and lead to disappointment with existing explanatory frameworks (with their high levels of abstraction, and limited predictive power). It is then argued that special discontent stems from misunderstandings and dislike of one well-known but atypical research programme: the study of adaptive function, in the tradition of behavioural ecology. To achieve its goals, this research needs distinct tools, often including imaginary agency, and a partial description of the evolutionary process. This invites mistaken charges of narrowness and oversimplification (which come, not least, from researchers in other subfields), and these chime with anxieties about human agency and overall purpose. The article ends by discussing several ways in which calls to reform evolutionary biology actively hinder progress in the field.}, }
@article {pmid28295032, year = {2017}, author = {Rode, NO and Soroye, P and Kassen, R and Rundle, HD}, title = {Air-borne genotype by genotype indirect genetic effects are substantial in the filamentous fungus Aspergillus nidulans.}, journal = {Heredity}, volume = {119}, number = {1}, pages = {1-7}, pmid = {28295032}, issn = {1365-2540}, mesh = {*Air Microbiology ; Aspergillus nidulans/*genetics/growth &amp; development ; *Genetic Fitness ; *Genotype ; Microbial Interactions/*genetics ; Models, Genetic ; Phenotype ; }, abstract = {Genotype by genotype indirect genetic effects (G × G IGEs) occur when the phenotype of an individual is influenced by an interaction between its own genotype and those of neighbour individuals. Little is known regarding the relative importance of G × G IGEs compared with other forms of direct and indirect genetic effects. We quantified the relative importance of IGEs in the filamentous fungus Aspergillus nidulans, a species in which IGEs are likely to be important as air-borne social interactions are known to affect growth. We used a collection of distantly related wild isolates, lab strains and a set of closely related mutation accumulation lines to estimate the contribution of direct and indirect genetic effects on mycelium growth rate, a key fitness component. We found that indirect genetic effects were dominated by G × G IGEs that occurred primarily between a focal genotype and its immediate neighbour within a vertical stack, and these accounted for 11% of phenotypic variation. These results indicate that G × G IGEs may be substantial, at least in some systems, and that the evolutionary importance of these interactions may be underappreciated, especially in microbes. We advocate for a wider use of the IGE framework in both applied (for example, choice of varietal mixtures in plant breeding) and evolutionary genetics (kin selection/kin competition studies).}, }
@article {pmid28280587, year = {2017}, author = {Murphy, GP and Van Acker, R and Rajcan, I and Swanton, CJ}, title = {Identity recognition in response to different levels of genetic relatedness in commercial soya bean.}, journal = {Royal Society open science}, volume = {4}, number = {1}, pages = {160879}, pmid = {28280587}, issn = {2054-5703}, abstract = {Identity recognition systems allow plants to tailor competitive phenotypes in response to the genetic relatedness of neighbours. There is limited evidence for the existence of recognition systems in crop species and whether they operate at a level that would allow for identification of different degrees of relatedness. Here, we test the responses of commercial soya bean cultivars to neighbours of varying genetic relatedness consisting of other commercial cultivars (intraspecific), its wild progenitor Glycine soja, and another leguminous species Phaseolus vulgaris (interspecific). We found, for the first time to our knowledge, that a commercial soya bean cultivar, OAC Wallace, showed identity recognition responses to neighbours at different levels of genetic relatedness. OAC Wallace showed no response when grown with other commercial soya bean cultivars (intra-specific neighbours), showed increased allocation to leaves compared with stems with wild soya beans (highly related wild progenitor species), and increased allocation to leaves compared with stems and roots with white beans (interspecific neighbours). Wild soya bean also responded to identity recognition but these responses involved changes in biomass allocation towards stems instead of leaves suggesting that identity recognition responses are species-specific and consistent with the ecology of the species. In conclusion, elucidating identity recognition in crops may provide further knowledge into mechanisms of crop competition and the relationship between crop density and yield.}, }
@article {pmid28233388, year = {2017}, author = {Erb, WM and Porter, LM}, title = {Mother's little helpers: What we know (and don't know) about cooperative infant care in callitrichines.}, journal = {Evolutionary anthropology}, volume = {26}, number = {1}, pages = {25-37}, doi = {10.1002/evan.21516}, pmid = {28233388}, issn = {1520-6505}, mesh = {Animals ; Anthropology, Physical ; *Biological Evolution ; Callitrichinae/*physiology ; *Cooperative Behavior ; Female ; Male ; *Maternal Behavior ; Selection, Genetic ; }, abstract = {Since Darwin (), scientists have been puzzled by how behaviors that impose fitness costs on helpers while benefiting their competitors could evolve through natural selection. Hamilton's () theory of inclusive fitness provided an explanation by showing how cooperative behaviors could be adaptive if directed at closely related kin. Recent studies, however, have begun to question whether kin selection is sufficient to explain cooperative behavior in some species (Bergmüller, Johnstone, Russell, &amp; Bshary,). Many researchers have instead emphasized the importance of direct fitness benefits for helpers in the evolution of cooperative breeding systems. Furthermore, individuals can vary in who, when, and how much they help, and the factors that affect this variation are poorly understood (Cockburn, ; Heinsohn,). Cooperative breeders thus provide excellent models for the study of evolutionary theories of cooperation and conflict (Cant,).}, }
@article {pmid28229624, year = {2017}, author = {Gray, PB and Brogdon, E}, title = {Do Step- and Biological Grandparents Show Differences in Investment and Emotional Closeness With Their Grandchildren?.}, journal = {Evolutionary psychology : an international journal of evolutionary approaches to psychology and behavior}, volume = {15}, number = {1}, pages = {1474704917694367}, pmid = {28229624}, issn = {1474-7049}, mesh = {Adult ; Female ; Grandparents/*psychology ; Humans ; *Intergenerational Relations ; Male ; }, abstract = {Human children are raised by a variety of caregivers including grandparents. A few studies have assessed potential differences in direct caregiving, financial expenditures, and emotional closeness between biological and step-grandparents. Drawing upon kin selection theory, we hypothesized that step-grandparents would provide less care and be less emotionally close to grandchildren than would biological grandparents. A sample of 341 heterosexual U.S. adults 25-35 years of age in a long-term partnership and with a biological child 5 years of age or younger were recruited via Amazon Mechanical Turk. Subjects provided sociodemographic information and answered questions about the dynamics between their own parent/stepparent and their own youngest biological child (hence, biological/step-grandparenting dynamics). Main analyses were restricted to within-subject comparisons. Results showed that biological grandmothers provided more direct childcare, financial expenditures, and had more emotionally close relationships with grandchildren than did step-grandmothers. Biological grandfathers provided less direct care and had less emotionally close relationships than step-grandfathers but did not exhibit differences in financial expenditures. Biological grandmothers provided more direct care, financial investment, and were more emotionally close to the referential grandchild than were biological grandfathers. Step-grandfathers were more emotionally close and more often played with grandchildren than step-grandmothers. These findings partially support kin selection theory. We discuss the relevance of factors such as competing demands on grandmothers' investment in biological and step-grandchildren and grandfathering serving in part as mating effort. Sex differences in biological grandparenting also mirror those in parenting. We suggest directions for future research, including on grandfathers, particularly in patrilineal societies.}, }
@article {pmid28202814, year = {2017}, author = {Vedder, O and Zhang, H and Bouwhuis, S}, title = {Early mortality saves energy: estimating the energetic cost of excess offspring in a seabird.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1849}, pages = {}, pmid = {28202814}, issn = {1471-2954}, mesh = {Animals ; Charadriiformes/*metabolism ; *Clutch Size ; Energy Intake ; *Mortality ; }, abstract = {Offspring are often produced in excess as insurance against stochastic events or unpredictable resources. This strategy may result in high early-life mortality, yet age-specific mortality before offspring independence and its associated costs have rarely been quantified. In this study, we modelled age-specific survival from hatching to fledging using 24 years of data on hatching order (HO), growth and age of mortality of more than 15 000 common tern (Sterna hirundo) chicks. We found that mortality peaked directly after hatching, after which it declined rapidly. Mortality hazard was best described with the Gompertz function, and was higher with later HO, mainly due to differences in baseline mortality hazard, rather than age-dependent mortality. Based on allometric mass-metabolism relationships and detailed growth curves of starving chicks, we estimated that the average metabolizable energy intake of non-fledged chicks was only 8.7% of the metabolizable energy intake of successful chicks during the nestling phase. Although 54% of hatchlings did not fledge, our estimates suggest them to have consumed only 9.3% of the total energy consumption of all hatched chicks in the population before fledging. We suggest that rapid mortality of excess offspring is part of an adaptive brood reduction strategy to the benefit of the parents.}, }
@article {pmid28107054, year = {2017}, author = {Andersson, M}, title = {Helping Relatives Survive and Reproduce: Inclusive Fitness and Reproductive Value in Brood Parasitism.}, journal = {The American naturalist}, volume = {189}, number = {2}, pages = {138-152}, doi = {10.1086/689991}, pmid = {28107054}, issn = {1537-5323}, mesh = {Animals ; Birds ; Female ; *Host-Parasite Interactions ; *Nesting Behavior ; *Reproduction ; Symbiosis ; }, abstract = {Costly help can raise a relative's reproduction, survival, and reproductive value and increase the inclusive fitness of the donor of help. Donor fitness is explored here in conspecific brood parasitism. In this alternative reproductive tactic, some females, "parasites," lay eggs in nests of other females of the same species, "hosts," suppliers of help that alone take care of the offspring. Modeling shows that hosts can gain inclusive fitness if parasitized by relatives whose reproduction or survival is thereby increased. These predictions are explored in waterfowl with frequent brood parasitism, female-biased philopatry, and neighbor relatedness. Approximate estimates based on waterfowl reproductive and life-history data show that host inclusive-fitness gain is often possible with related parasites. The largest gains can be achieved through increased reproduction, but gain is also possible through higher survival of parasites that avoid increased predation and other risks of nesting. Inclusive fitness depends on parasite reproductive value and can be highest for a host parasitized by her mother and for old, senescent hosts with low fecundity, helping young related parasites. These results and observed levels of host-parasite relatedness suggest that being "parasitized" in waterfowl is sometimes neutral or even advantageous because of inclusive-fitness benefits, contributing to evolution of frequent conspecific brood parasitism in this group.}, }
@article {pmid28089514, year = {2017}, author = {Croft, DP and Johnstone, RA and Ellis, S and Nattrass, S and Franks, DW and Brent, LJ and Mazzi, S and Balcomb, KC and Ford, JK and Cant, MA}, title = {Reproductive Conflict and the Evolution of Menopause in Killer Whales.}, journal = {Current biology : CB}, volume = {27}, number = {2}, pages = {298-304}, doi = {10.1016/j.cub.2016.12.015}, pmid = {28089514}, issn = {1879-0445}, mesh = {Animals ; *Biological Evolution ; Female ; *Menopause ; Reproduction ; Whale, Killer/*physiology ; }, abstract = {Why females of some species cease ovulation prior to the end of their natural lifespan is a long-standing evolutionary puzzle [1-4]. The fitness benefits of post-reproductive helping could in principle select for menopause [1, 2, 5], but the magnitude of these benefits appears insufficient to explain the timing of menopause [6-8]. Recent theory suggests that the cost of inter-generational reproductive conflict between younger and older females of the same social unit is a critical missing term in classical inclusive fitness calculations (the "reproductive conflict hypothesis" [6, 9]). Using a unique long-term dataset on wild resident killer whales, where females can live decades after their final parturition, we provide the first test of this hypothesis in a non-human animal. First, we confirm previous theoretical predictions that local relatedness increases with female age up to the end of reproduction. Second, we construct a new evolutionary model and show that given these kinship dynamics, selection will favor younger females that invest more in competition, and thus have greater reproductive success, than older females (their mothers) when breeding at the same time. Third, we test this prediction using 43 years of individual-based demographic data in resident killer whales and show that when mothers and daughters co-breed, the mortality hazard of calves from older-generation females is 1.7 times that of calves from younger-generation females. Intergenerational conflict combined with the known benefits conveyed to kin by post-reproductive females can explain why killer whales have evolved the longest post-reproductive lifespan of all non-human animals.}, }
@article {pmid28079112, year = {2017}, author = {Lewin-Epstein, O and Aharonov, R and Hadany, L}, title = {Microbes can help explain the evolution of host altruism.}, journal = {Nature communications}, volume = {8}, number = {}, pages = {14040}, pmid = {28079112}, issn = {2041-1723}, mesh = {*Altruism ; *Biological Evolution ; *Microbiota ; *Models, Genetic ; }, abstract = {The evolution of altruistic behaviour, which is costly to the donor but beneficial for the recipient, is among the most intriguing questions in evolutionary biology. Several theories have been proposed to explain it, including kin selection, group selection and reciprocity. Here we propose that microbes that manipulate their hosts to act altruistically could be favoured by selection, and may play a role in the widespread occurrence of altruism. Using computational models, we find that microbe-induced altruism can explain the evolution of host altruistic behaviour under wider conditions than host-centred theories, including in a fully mixed host population, without repeating interactions or individual recognition. Our results suggest that factors such as antibiotics that kill microbes might negatively affect cooperation in a wide range of organisms.}, }
@article {pmid28066387, year = {2016}, author = {Zhang, Z and Claessen, D and Rozen, DE}, title = {Understanding Microbial Divisions of Labor.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {2070}, pmid = {28066387}, issn = {1664-302X}, abstract = {Divisions of labor are ubiquitous in nature and can be found at nearly every level of biological organization, from the individuals of a shared society to the cells of a single multicellular organism. Many different types of microbes have also evolved a division of labor among its colony members. Here we review several examples of microbial divisions of labor, including cases from both multicellular and unicellular microbes. We first discuss evolutionary arguments, derived from kin selection, that allow divisions of labor to be maintained in the face of non-cooperative cheater cells. Next we examine the widespread natural variation within species in their expression of divisions of labor and compare this to the idea of optimal caste ratios in social insects. We highlight gaps in our understanding of microbial caste ratios and argue for a shift in emphasis from understanding the maintenance of divisions of labor, generally, to instead focusing on its specific ecological benefits for microbial genotypes and colonies. Thus, in addition to the canonical divisions of labor between, e.g., reproductive and vegetative tasks, we may also anticipate divisions of labor to evolve to reduce the costly production of secondary metabolites or secreted enzymes, ideas we consider in the context of streptomycetes. The study of microbial divisions of labor offers opportunities for new experimental and molecular insights across both well-studied and novel model systems.}, }
@article {pmid28057829, year = {2017}, author = {Matsuura, K}, title = {Evolution of the asexual queen succession system and its underlying mechanisms in termites.}, journal = {The Journal of experimental biology}, volume = {220}, number = {Pt 1}, pages = {63-72}, doi = {10.1242/jeb.142547}, pmid = {28057829}, issn = {1477-9145}, mesh = {Animals ; *Biological Evolution ; Female ; Genomic Imprinting ; Isoptera/genetics/*physiology ; Male ; Parthenogenesis ; Pheromones/metabolism ; Reproduction ; *Reproduction, Asexual ; Sex Ratio ; Sexual Behavior, Animal ; }, abstract = {One major advantage of sexual reproduction over asexual reproduction is its promotion of genetic variation, although it reduces the genetic contribution to offspring. Queens of social insects double their contribution to the gene pool, while overuse of asexual reproduction may reduce the ability of the colony to adapt to environmental stress because of the loss of genetic diversity. Recent studies have revealed that queens of some termite species can solve this tradeoff by using parthenogenesis to produce the next generation of queens and sexual reproduction to produce other colony members. This reproductive system, known as asexual queen succession (AQS), has been identified in the subterranean termites Reticulitermes speratus, Reticulitermes virginicus and Reticulitermes lucifugus and in the Neotropical higher termites Embiratermes neotenicus and Cavitermes tuberosus The studies presented here have uncovered the unusual modes of reproduction in termites and have aimed to identify their underlying mechanisms. The study of AQS, the mixed use of sexual and asexual reproduction, is of fundamental importance as it may provide a key to solve the evolutionary paradox of sex.}, }
@article {pmid31572069, year = {2017}, author = {Graves, CJ and Weinreich, DM}, title = {Variability in fitness effects can preclude selection of the fittest.}, journal = {Annual review of ecology, evolution, and systematics}, volume = {48}, number = {1}, pages = {399-417}, pmid = {31572069}, issn = {1543-592X}, support = {R01 GM095728/GM/NIGMS NIH HHS/United States ; }, abstract = {Evolutionary biologists often predict the outcome of natural selection on an allele by measuring its effects on lifetime survival and reproduction of individual carriers. However, alleles affecting traits like sex, evolvability, and cooperation can cause fitness effects that depend heavily on differences in the environmental, social, and genetic context of individuals carrying the allele. This variability makes it difficult to summarize the evolutionary fate of an allele based solely on its effects on any one individual. Attempts to average over this variability can sometimes salvage the concept of fitness. In other cases evolutionary outcomes can only be predicted by considering the entire genealogy of an allele, thus limiting the utility of individual fitness altogether. We describe a number of intriguing new evolutionary phenomena that have emerged in studies that explicitly model long-term lineage dynamics and discuss implications for the evolution of infectious diseases.}, }
@article {pmid28035273, year = {2016}, author = {Procter, DS and Cottrell, JE and Watts, K and A'Hara, SW and Hofreiter, M and Robinson, EJ}, title = {Does cooperation mean kinship between spatially discrete ant nests?.}, journal = {Ecology and evolution}, volume = {6}, number = {24}, pages = {8846-8856}, pmid = {28035273}, issn = {2045-7758}, abstract = {Eusociality is one of the most complex forms of social organization, characterized by cooperative and reproductive units termed colonies. Altruistic behavior of workers within colonies is explained by inclusive fitness, with indirect fitness benefits accrued by helping kin. Members of a social insect colony are expected to be more closely related to one another than they are to other conspecifics. In many social insects, the colony can extend to multiple socially connected but spatially separate nests (polydomy). Social connections, such as trails between nests, promote cooperation and resource exchange, and we predict that workers from socially connected nests will have higher internest relatedness than those from socially unconnected, and noncooperating, nests. We measure social connections, resource exchange, and internest genetic relatedness in the polydomous wood ant Formica lugubris to test whether (1) socially connected but spatially separate nests cooperate, and (2) high internest relatedness is the underlying driver of this cooperation. Our results show that socially connected nests exhibit movement of workers and resources, which suggests they do cooperate, whereas unconnected nests do not. However, we find no difference in internest genetic relatedness between socially connected and unconnected nest pairs, both show high kinship. Our results suggest that neighboring pairs of connected nests show a social and cooperative distinction, but no genetic distinction. We hypothesize that the loss of a social connection may initiate ecological divergence within colonies. Genetic divergence between neighboring nests may build up only later, as a consequence rather than a cause of colony separation.}, }
@article {pmid28028377, year = {2016}, author = {Preston, SA and Briskie, JV and Hatchwell, BJ}, title = {Adult helpers increase the recruitment of closely related offspring in the cooperatively breeding rifleman.}, journal = {Behavioral ecology : official journal of the International Society for Behavioral Ecology}, volume = {27}, number = {6}, pages = {1617-1626}, pmid = {28028377}, issn = {1045-2249}, abstract = {Indirect fitness benefits gained through kin-selected helping are widely invoked to explain the evolution of cooperative breeding behavior in birds. However, the impact of helpers on productivity of helped broods can be difficult to determine if the effects are confounded by territory quality or if the benefit of helpers is apparent only in the long term. In riflemen Acanthisitta chloris, helping and group membership are effectively decoupled as adult helpers are individuals that have dispersed from their natal territory and live independently from breeders in "kin neighborhoods." Nevertheless, helpers direct their care toward close relatives, suggesting that helping provides indirect fitness benefits. The aim of this study was to examine the benefits of helpers to recipient offspring in the rifleman, investigating both short- and long-term effects. The total amount of food delivered to nestlings in helped broods was greater than that received by broods without helpers. This did not result in any short-term increase in nestling mass or nestling body condition nor was there any reduction in length of the nestling period at helped nests. However, helpers were associated with a significant increase in juvenile recruitment, with twice the proportion of fledglings surviving to the next breeding season from helped broods relative to unhelped broods. Thus, helpers gain indirect fitness by improving the survival of kin, and in contrast to a previous study of riflemen, we conclude that kin selection has played a key role in the evolution of cooperative breeding in this species.}, }
@article {pmid28018027, year = {2017}, author = {Widdig, A and Muniz, L and Minkner, M and Barth, Y and Bley, S and Ruiz-Lambides, A and Junge, O and Mundry, R and Kulik, L}, title = {Low incidence of inbreeding in a long-lived primate population isolated for 75 years.}, journal = {Behavioral ecology and sociobiology}, volume = {71}, number = {1}, pages = {18}, pmid = {28018027}, issn = {0340-5443}, support = {P40 OD012217/OD/NIH HHS/United States ; }, abstract = {ABSTRACT: When close relatives mate, offspring are expected to suffer fitness consequences due to inbreeding depression. Inbreeding has previously been quantified in two ways: using a sufficiently large panel of markers or deep and complete pedigrees over several generations. However, the application of both approaches is still limited by the challenge of compiling such data for species with long generation times, such as primates. Here, we assess inbreeding in rhesus macaques living on Cayo Santiago (Puerto Rico), a population genetically isolated since 1938, but descendant of a large set of presumably unrelated founders. Using comprehensive genetic data, we calculated inbreeding coefficients (F) for 2669 individuals with complete three generation pedigrees and 609 individuals with complete four generation pedigrees. We found that 0.79 and 7.39% of individuals had an F > 0 when using data from three and four generation pedigrees, respectively. No evidence of an increase in inbreeding over the study period (up to 23 years) was found. Furthermore, the observed mean relatedness of breeding pairs differed significantly from the distribution of parental relatedness expected as simulated based on previous reproductive data, suggesting that kin generally avoid breeding with each other. Finally, inbreeding was not a predictor of early mortality measured as survival until weaning and sexual maturation, respectively. Our results remain consistent with three estimators of inbreeding (standardized heterozygosity, internal relatedness, and homozygosity by loci) using up to 42 highly polymorphic microsatellites for the same set of individuals. Together, our results demonstrate that close inbreeding may not be prevalent even in populations isolated over long periods when mechanisms of inbreeding avoidance can operate.<br><br>SIGNIFICANCE STATEMENT: When close relatives mate, offspring may suffer from such inbreeding, e.g., via lower survival and/or fertility. Using (i) a large panel of genetic markers and (ii) complete three or four generation pedigrees, respectively, we show that incidences of inbreeding in a long-lived primate population are rare, even after genetic isolation for 75&#xa0;years. Moreover, our simulations suggest that kin in our population generally avoid breeding with each other. Finally, the few inbred individuals detected in our large sample did not suffer from lower survival. Given that many animal species face dramatic habitat loss combined with critical population declines, our study provides important implications for conservation biology in general and for population management in particular.}, }
@article {pmid28012185, year = {2017}, author = {Taylor, P}, title = {Inclusive fitness in finite populations-effects of heterogeneity and synergy.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {3}, pages = {508-525}, doi = {10.1111/evo.13160}, pmid = {28012185}, issn = {1558-5646}, mesh = {Game Theory ; *Gene Frequency ; *Genetic Fitness ; Models, Genetic ; Population Density ; *Selection, Genetic ; }, abstract = {I review recent results concerning the relationship between the inclusive fitness (IF) effect and standard measures of allele fitness in a finite-population, with attention to the effect of heterogeneity in population structure and nonadditive fitness effects. In both cases, existing theoretical work is somewhat technical and I try to provide a more transparent account. In a heterogeneous population it is known that inclusive fitness will generally fail to incorporate the effects of selection on the distribution of alleles among states unless a reproductive-value weighting is used. But even given that, recent work shows that under certain updating rules, the IF effect can fail to be equivalent to standard measures such as fixation probability. In terms of synergistic fitness effects, I review the result that in the finite population model, the IF effect can be calculated using only "additive" relatedness coefficients so that computational difficulties found in the infinite-population model do not arise. In my own work, there is an interaction here in that my 2012 work on synergy with Maciejewski made an assumption about inclusive fitness that my 2014 work on heterogeneity with Tarnita showed to be wrong. I include (Appendix C) a corrected argument for the 2012 result.}, }
@article {pmid27991659, year = {2017}, author = {Faria, GS and Varela, SA and Gardner, A}, title = {Sexual selection modulates genetic conflicts and patterns of genomic imprinting.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {3}, pages = {526-540}, pmid = {27991659}, issn = {1558-5646}, mesh = {Alleles ; *Animal Distribution ; Animals ; Female ; *Genetic Fitness ; *Genomic Imprinting ; Invertebrates/*genetics/physiology ; Male ; Models, Genetic ; Population Density ; Selection, Genetic ; Sex Factors ; Vertebrates/*genetics/physiology ; }, abstract = {Recent years have seen a surge of interest in linking the theories of kin selection and sexual selection. In particular, there is a growing appreciation that kin selection, arising through demographic factors such as sex-biased dispersal, may modulate sexual conflicts, including in the context of male-female arms races characterized by coevolutionary cycles. However, evolutionary conflicts of interest need not only occur between individuals, but may also occur within individuals, and sex-specific demography is known to foment such intragenomic conflict in relation to social behavior. Whether and how this logic holds in the context of sexual conflict-and, in particular, in relation to coevolutionary cycles-remains obscure. We develop a kin-selection model to investigate the interests of different genes involved in sexual and intragenomic conflict, and we show that consideration of these conflicting interests yields novel predictions concerning parent-of-origin specific patterns of gene expression and the detrimental effects of different classes of mutation and epimutation at loci underpinning sexually selected phenotypes.}, }
@article {pmid27990255, year = {2016}, author = {Newman, SJ and Eyre, S and Kimble, CH and Arcos-Burgos, M and Hogg, C and Easteal, S}, title = {Reproductive success is predicted by social dynamics and kinship in managed animal populations.}, journal = {F1000Research}, volume = {5}, number = {}, pages = {870}, pmid = {27990255}, issn = {2046-1402}, abstract = {Kin and group interactions are important determinants of reproductive success in many species. Their optimization could, therefore, potentially improve the productivity and breeding success of managed populations used for agricultural and conservation purposes. Here we demonstrate this potential using a novel approach to measure and predict the effect of kin and group dynamics on reproductive output in a well-known species, the meerkat Suricata suricatta. Variation in social dynamics predicts 30% of the individual variation in reproductive success of this species in managed populations, and accurately forecasts reproductive output at least two years into the future. Optimization of social dynamics in captive meerkat populations doubles their projected reproductive output. These results demonstrate the utility of a quantitative approach to breeding programs informed by social and kinship dynamics. They suggest that this approach has great potential for improvements in the management of social endangered and agricultural species.}, }
@article {pmid27987088, year = {2017}, author = {VanderLaan, DP and Petterson, LJ and Vasey, PL}, title = {Elevated Kin-Directed Altruism Emerges in Childhood and Is Linked to Feminine Gender Expression in Samoan Fa'afafine: A Retrospective Study.}, journal = {Archives of sexual behavior}, volume = {46}, number = {1}, pages = {95-108}, doi = {10.1007/s10508-016-0884-2}, pmid = {27987088}, issn = {1573-2800}, mesh = {Adult ; *Altruism ; Female ; Gender Identity ; Homosexuality, Male/*ethnology ; Humans ; Male ; Reproduction ; Retrospective Studies ; Samoa ; Sexual Behavior/*ethnology ; Siblings ; }, abstract = {Androphilia refers to sexual attraction toward adult males, whereas gynephilia refers to sexual attraction toward adult females. The kin selection hypothesis posits that androphilic males help kin increase their reproductive output via kin-directed altruism, thus offsetting their own lowered reproduction and contributing to the fitness of genes underpinning male androphilia. Support for this hypothesis has been garnered in several Samoan studies showing that feminine androphilic males (known locally as fa'afafine) report elevated willingness to invest in nieces and nephews in adulthood. Also, recalled childhood kin attachment and concern for kin's well-being are elevated among Canadian androphilic males (i.e., gay men) and positively associated with childhood feminine gender expression. This study examined whether these childhood patterns were cross-culturally consistent and associated with adulthood kin-directed altruism in a Samoan sample. Samoan gynephilic men, androphilic women, and fa'afafine (N = 470) completed measures of recalled childhood kin attachment and concern for the well-being of kin, recalled childhood gender expression, and willingness in adulthood to invest in nieces and nephews. Fa'afafine recalled elevated anxiety due to separation from kin relative to men and elevated concern for kin's well-being relative to both men and women. Within groups, these characteristics were most robustly associated with childhood feminine gender expression and willingness in adulthood to invest in nieces and nephews among fa'afafine. These findings are consistent with the kin selection hypothesis and the adaptive feminine phenotype model, which proposes that a disposition toward elevated kin-directed altruism among androphilic males is associated with feminine gender expression.}, }
@article {pmid27951454, year = {2017}, author = {Allen-Hermanson, S}, title = {Kamikazes and cultural evolution.}, journal = {Studies in history and philosophy of biological and biomedical sciences}, volume = {61}, number = {}, pages = {11-19}, doi = {10.1016/j.shpsc.2016.12.001}, pmid = {27951454}, issn = {1879-2499}, mesh = {*Altruism ; Biological Evolution ; *Cultural Evolution ; Humans ; Japan ; Selection, Genetic ; *Warfare ; }, abstract = {Is cultural evolution needed to explain altruistic selfsacrifice? Some contend that cultural traits (e.g. beliefs, behaviors, and for some "memes") replicate according to selection processes that have "floated free" from biology. One test case is the example of suicide kamikaze attacks in wartime Japan. Standard biological mechanisms-such as reciprocal altruism and kin selection-might not seem to apply here: The suicide pilots did not act on the expectation that others would reciprocate, and they were supposedly sacrificing themselves for country and emperor, not close relatives. Yet an examination of both the historical record and the demands of evolutionary theory suggest the kamikaze phenomenon does not cry out for explanation in terms of a special non-biological selection process. This weakens the case for cultural evolution, and has interesting implications for our understanding of altruistic self-sacrifice.}, }
@article {pmid27925168, year = {2017}, author = {Tan, CK and Doyle, P and Bagshaw, E and Richardson, DS and Wigby, S and Pizzari, T}, title = {The contrasting role of male relatedness in different mechanisms of sexual selection in red junglefowl.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {2}, pages = {403-420}, pmid = {27925168}, issn = {1558-5646}, support = {BB/K014544/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Chickens/genetics/*physiology ; Competitive Behavior ; Copulation ; Female ; Male ; *Mating Preference, Animal ; Spermatozoa/*physiology ; }, abstract = {In structured populations, competition for reproductive opportunities should be relaxed among related males. The few tests of this prediction often neglect the fact that sexual selection acts through multiple mechanisms, both before and after mating. We performed experiments to study the role of within-group male relatedness across pre- and postcopulatory mechanisms of sexual selection in social groups of red junglefowl, Gallus gallus, in which two related males and one unrelated male competed over females unrelated to all the males. We confirm theoretical expectations that, after controlling for male social status, competition over mating was reduced among related males. However, this effect was contrasted by other sexual selection mechanisms. First, females biased male mating in favor of the unrelated male, and might also favor his inseminations after mating. Second, males invested more-rather than fewer-sperm in postcopulatory competition with relatives. A number of factors may contribute to explain this counterintuitive pattern of sperm allocation, including trade-offs between male investment in pre- versus postcopulatory competition, differences in the relative relatedness of pre- versus postcopulatory competitors, and female bias in sperm utilization in response to male relatedness. Collectively, these results reveal that within-group male relatedness may have contrasting effects in different mechanisms of sexual selection.}, }
@article {pmid27910006, year = {2016}, author = {Coco, E}, title = {William D. Hamilton's Brazilian lectures and his unpublished model regarding Wynne-Edwards's idea of natural selection. With a note on 'pluralism' and different philosophical approaches to evolution.}, journal = {History and philosophy of the life sciences}, volume = {38}, number = {4}, pages = {24}, doi = {10.1007/s40656-016-0125-y}, pmid = {27910006}, issn = {0391-9714}, mesh = {Animals ; *Biological Evolution ; Brazil ; England ; *Genetic Variation ; Genetics, Population/*history ; History, 20th Century ; Manuscripts as Topic ; *Selection, Genetic ; *Social Behavior ; }, abstract = {In 1975, the English evolutionist William Donald Hamilton (1936-2000) held in Brazil a series of lectures entitled "Population genetics and social behaviour". The unpublished notes of these conferences-written by Hamilton and recently discovered at the British Library-offer an opportunity to reflect on some of the author's ideas about evolution. The year of the conference is particularly significant, as it took place shortly after the applications of the Price equation with which Hamilton was able to build a model that included several levels of selection. In this paper I mainly analyse the inaugural lecture in which Hamilton proposes a simple model to disprove the hypothesis supported by the British zoologist C. Vero Wynne-Edwards (1906-1997) regarding mechanisms to prevent "over-exploitation of the food supply" in "the interests of the survival of the group". The document presented here is of great historical interest. Not only because manuscript offers a model that-since it was intended for teaching purposes-had never before appeared in the published version, but also because of the general index of the lectures that accompanies it. The latter allows us to make some hypothetical considerations on the relationship and differences between kin-selection, group-selection and inclusive fitness that Hamilton wanted to present to the attentive, well-prepared audience of the foreign university that had invited him.}, }
@article {pmid27881747, year = {2016}, author = {Duthie, AB and Lee, AM and Reid, JM}, title = {Inbreeding parents should invest more resources in fewer offspring.}, journal = {Proceedings. Biological sciences}, volume = {283}, number = {1843}, pages = {}, pmid = {27881747}, issn = {1471-2954}, mesh = {Animals ; Female ; *Genetic Fitness ; *Inbreeding ; Male ; *Mating Preference, Animal ; Models, Genetic ; *Reproduction ; }, abstract = {Inbreeding increases parent-offspring relatedness and commonly reduces offspring viability, shaping selection on reproductive interactions involving relatives and associated parental investment (PI). Nevertheless, theories predicting selection for inbreeding versus inbreeding avoidance and selection for optimal PI have only been considered separately, precluding prediction of optimal PI and associated reproductive strategy given inbreeding. We unify inbreeding and PI theory, demonstrating that optimal PI increases when a female's inbreeding decreases the viability of her offspring. Inbreeding females should therefore produce fewer offspring due to the fundamental trade-off between offspring number and PI. Accordingly, selection for inbreeding versus inbreeding avoidance changes when females can adjust PI with the degree that they inbreed. By contrast, optimal PI does not depend on whether a focal female is herself inbred. However, inbreeding causes optimal PI to increase given strict monogamy and associated biparental investment compared with female-only investment. Our model implies that understanding evolutionary dynamics of inbreeding strategy, inbreeding depression, and PI requires joint consideration of the expression of each in relation to the other. Overall, we demonstrate that existing PI and inbreeding theories represent special cases of a more general theory, implying that intrinsic links between inbreeding and PI affect evolution of behaviour and intrafamilial conflict.}, }
@article {pmid27859791, year = {2016}, author = {Schultner, E and Saramäki, J and Helanterä, H}, title = {Genetic structure of native ant supercolonies varies in space and time.}, journal = {Molecular ecology}, volume = {25}, number = {24}, pages = {6196-6213}, doi = {10.1111/mec.13912}, pmid = {27859791}, issn = {1365-294X}, mesh = {Animals ; Ants/*genetics ; Finland ; *Genetics, Population ; Social Behavior ; Spatio-Temporal Analysis ; }, abstract = {Ant supercolonies are the largest cooperative units known in nature. They consist of networks of interconnected nests with hundreds of reproductive queens, where individuals move freely between nests, cooperate across nest boundaries and show little aggression towards non-nestmates. The combination of high queen numbers and free mixing of workers, queens and brood between nests results in extremely low nestmate relatedness. In such low-relatedness societies, cooperative worker behaviour appears maladaptive because it may aid random individuals instead of relatives. Here, we provide a comprehensive picture of genetic substructure in supercolonies of the native wood ant Formica aquilonia using traditional population genetic as well as network analysis methods. Specifically, we test for spatial and temporal variation in genetic structure of different classes of individuals within supercolonies and analyse the role of worker movement in determining supercolony genetic networks. We find that relatedness within supercolonies is low but positive when viewed on a population level, which may be due to limited dispersal of individuals and/or ecological factors such as nest site limitation and competition against conspecifics. Genetic structure of supercolonies varied with both sample class and sampling time point, which indicates that mobility of individuals varies according to both caste and season and suggests that generalizing has to be carried out with caution in studies of supercolonial species. Overall, our analysis provides novel evidence that native wood ant supercolonies exhibit fine-scale genetic substructure, which may explain the maintenance of cooperation in these low-relatedness societies.}, }
@article {pmid27852800, year = {2016}, author = {Bawa, KS}, title = {Kin selection and the evolution of plant reproductive traits.}, journal = {Proceedings. Biological sciences}, volume = {283}, number = {1842}, pages = {}, pmid = {27852800}, issn = {1471-2954}, mesh = {*Biological Evolution ; Flowers/genetics ; Phenotype ; *Plant Physiological Phenomena ; Plants/*genetics ; Pollen/genetics ; *Pollination ; Reproduction ; Seeds/*genetics ; }, abstract = {Competition among developing seeds and sibling rivalry within multiovulated ovaries can be deleterious for both the maternal parent and the siblings. Increased genetic relatedness of seeds within the ovary may foster kin selection and reduce the deleterious consequences of sibling competition. The pollen parent may also be selected for siring all progeny within a fruit. I propose a series of hypotheses to explain the evolution of a number of reproductive traits in angiosperms in the context of kin selection and sibling rivalry within the ovaries of angiosperms. I present evidence to show that a single-pollen parent, indeed, often sires seeds within multiovulated ovaries. Various types of pollen aggregations and transfer of such pollen masses to the stigmas of flowers by specialized pollinators make this increased genetic relatedness possible. An alternative mode to reduce sibling rivalry may be the reduction of ovule number to one, an evolutionary trend that has independently occurred many times in flowering plants. Finally, I build on previously established correlations to predict two sets of correlations among reproductive traits. In the first case, large showy flowers, transfer of pollen en masse by specialized pollinators, and multiovulated ovaries and multisided fruits seem to be correlated. In the second case, the previously established correlations among small and inconspicuous flowers, pollination by wind, water or generalist insects, flowers and fruits with few or single ovules and seeds, respectively, may also include monoecy or dioecy. Although correlations among many of these traits have been established in the past, I invoke kin selection and sibling competition to explain the evolution of correlated traits as two distinct evolutionary pathways in angiosperms.}, }
@article {pmid27812427, year = {2016}, author = {Saberski, ET and Diamond, JD and Henneman, NF and Levitis, DA}, title = {Post-reproductive parthenogenetic pea aphids (Acyrthosiphon pisum) are visually identifiable and disproportionately positioned distally to clonal colonies.}, journal = {PeerJ}, volume = {4}, number = {}, pages = {e2631}, pmid = {27812427}, issn = {2167-8359}, support = {P20 GM103423/GM/NIGMS NIH HHS/United States ; }, abstract = {The role of ki