Social evolution

  • Article
    | Open Access

    Obscuring knowledge of personal gains from individuals can theoretically maintain fairness in a cooperative group. Experiments show that wild, cooperatively breeding banded mongooses uncertain of kinship allocate postnatal care in a way that reduces inequality among offspring, suggesting a classic idea of moral philosophy can apply in biological systems.

    • H. H. Marshall
    • , R. A. Johnstone
    •  & M. A. Cant
  • Article
    | Open Access

    Here, the authors examine how altruism can emerge as people come to trust a public institution of moral assessment, which broadcasts whether individuals have good or bad reputations for reciprocity.

    • Arunas L. Radzvilavicius
    • , Taylor A. Kessinger
    •  & Joshua B. Plotkin
  • Article
    | Open Access

    Social interaction outcomes can depend on the type of information individuals possess and how it is used in decision-making. Here, Zhou et al. find that self-evaluation based decision-making rules lead to evolutionary outcomes that are robust to different population structures and ways of self-evaluation.

    • Lei Zhou
    • , Bin Wu
    •  & Long Wang
  • Article
    | Open Access

    Many obligate symbionts, including parasites, have reduced genomes. A comparison of leaf-cutter ant genomes reveals parallel gene losses, particularly in olfactory receptors, in socially parasitic species compared to their closely-related hosts, consistent with relaxed selection for cooperative colony life in the parasites.

    • Lukas Schrader
    • , Hailin Pan
    •  & Christian Rabeling
  • Article
    | Open Access

    Social animals have sophisticated ways of classifying relationships with conspecifics. Data from 30 years of observations and playback experiments on dolphins with a multi-level alliance system show that individuals form social concepts that categorize conspecifics according to their shared cooperative history.

    • Stephanie L. King
    • , Richard C. Connor
    •  & Simon J. Allen
  • Article
    | Open Access

    Mycelial fusion can favour fungal strains that exploit each other, but the mechanism is not well understood. Here, Grum-Grzhimaylo et al. show that different cheater lineages share similar deficiencies in initiating fusion that nevertheless enable them to preferentially obtain the benefits of fusion initiated by wild-type mycelia.

    • Alexey A. Grum-Grzhimaylo
    • , Eric Bastiaans
    •  & Duur K. Aanen
  • Article
    | Open Access

    Strong social bonds are known to affect pairwise cooperation in primates such chimpanzees. Here, Samuni et al. show that strong social bonds also influence participation in group-level cooperation (collective action in intergroup encounters) using a long-term dataset of wild chimpanzees.

    • Liran Samuni
    • , Catherine Crockford
    •  & Roman M. Wittig
  • Article
    | Open Access

    As spiteful behaviors harm both the actor and the target, it is challenging to understand how these behaviors could be adaptive. Here Fulker et al. show that spite can be favored by feedbacks with network structure that create correlated and anti-correlated behavioral interactions simultaneously.

    • Zachary Fulker
    • , Patrick Forber
    •  & Christoph Riedl
  • Article
    | Open Access

    The causes and consequences of social intelligence are challenging to establish. A study on wild cleaner fish reports that large forebrains enable individuals to score higher in a social competence test, suggesting forebrain size is important for complex social decision-making.

    • Zegni Triki
    • , Yasmin Emery
    •  & Redouan Bshary
  • Perspective
    | Open Access

    The social intelligence hypothesis predicts that social organisms tend to be more intelligent because within-group interactions drive cognitive evolution. Here, authors propose that conspecific outsiders can be just as important in selecting for sophisticated cognitive adaptations.

    • Benjamin J. Ashton
    • , Patrick Kennedy
    •  & Andrew N. Radford
  • Article
    | Open Access

    Most evolutionary game theory focuses on isolated games. Here, Donahue et al. present a general framework for ‘multichannel games’ in which individuals engage in a set of parallel games with a partner, and show that such parallel interactions favor the evolution of reciprocity across games.

    • Kate Donahue
    • , Oliver P. Hauser
    •  & Christian Hilbe
  • Article
    | Open Access

    People regularly punish norm violations using gossip and direct confrontation. Here, the authors show that the use of gossip versus direct confrontation is context sensitive, with confrontation used more when punishers have more to gain, and gossip used more when the costs of retaliation loom large.

    • Catherine Molho
    • , Joshua M. Tybur
    •  & Daniel Balliet
  • Article
    | Open Access

    Cleaner fish can cheat clients for higher rewards but this comes with a risk of punishment. Here, Truskanov et al. show that juvenile cleaner fish can learn by observing adults to behave more cooperatively themselves but also to prefer clients that are more tolerant to cheating.

    • Noa Truskanov
    • , Yasmin Emery
    •  & Redouan Bshary
  • Article
    | Open Access

    Strategic game payoffs often depend on the state of the environment, which in turn can be influenced by game strategies. Here, Tilman et al. develop a general framework for modeling strategic games with environmental feedbacks and analyze case studies from decision-making, ecology, and economics.

    • Andrew R. Tilman
    • , Joshua B. Plotkin
    •  & Erol Akçay
  • Article
    | Open Access

    Learning can involve the integration of individual and social information but disentangling these is challenging. Here, Canteloup and colleagues investigate social learning dynamics and transmission biases in wild vervet monkeys and how social information influences further asocial learning.

    • Charlotte Canteloup
    • , William Hoppitt
    •  & Erica van de Waal
  • Article
    | Open Access

    Acoustic communication is widespread, but not universal, across terrestrial vertebrates. Here, the authors show that acoustic communication evolved anciently, but independently, in most tetrapod groups and that these origins were associated with nocturnal activity.

    • Zhuo Chen
    •  & John J. Wiens
  • Article
    | Open Access

    Market integration may loosen the dense kinship networks maintaining high fertility among agriculturalists, but data are lacking. Here, Colleran shows that in 22 rural Polish communities, women’s ego networks are less kin-oriented, but not less dense, as market integration increases, potentially enabling low fertility values to spread.

    • Heidi Colleran
  • Article
    | Open Access

    The ‘parliament of genes’ hypothesis suggests that selfish genetic elements will be counteracted by suppressors that maintain equal transmission of the rest of the genome. Here, the authors find support for this hypothesis using mathematical models to explore a range of different scenarios.

    • Thomas W. Scott
    •  & Stuart A. West
  • Article
    | Open Access

    Quorum sensing (QS) regulates production of ‘public goods’ by Pseudomonas aeruginosa, which releases toxic hydrogen cyanide to constrain QS-deficient cheaters. Here, Yan et al. show that QS-proficient strains protect themselves by producing a cyanide-insensitive enzyme in response to reactive oxygen species released by cheaters.

    • Huicong Yan
    • , Kyle L. Asfahl
    •  & Meizhen Wang
  • Article
    | Open Access

    Parental care can take many forms but how this diversity arises is not well understood. Here, the authors compile data for over 1300 amphibian species and show that different forms of care evolve at different rates, prolonged care can be easily reduced, and biparental care is evolutionarily unstable.

    • Andrew I. Furness
    •  & Isabella Capellini
  • Article
    | Open Access

    Compared to motherhood, the molecular changes associated with fatherhood are less understood. Here, the authors investigate gene expression changes associated with paternal care in male stickleback fish, and compare them with patterns in territorial aggression.

    • Syed Abbas Bukhari
    • , Michael C. Saul
    •  & Alison M. Bell
  • Article
    | Open Access

    The fish Astyanax mexicanus has divergent cave and river-dwelling eco-morphotypes. Here, Hyacinthe et al. show that cave and river fish communicate sonically, but that the sounds produced and the responses elicited in the two morphs depend differently on the social and behavioral context.

    • Carole Hyacinthe
    • , Joël Attia
    •  & Sylvie Rétaux
  • Article
    | Open Access

    Genetic diversity in social genes is expected to be shaped by conflict. Here, the authors show that in Dictyostelium discoideum, social genes in fact exhibit diversification patterns consistent with relaxed purifying selection, likely due to their expression only in intermittent social generations.

    • Janaina Lima de Oliveira
    • , Atahualpa Castillo Morales
    •  & Jason B. Wolf
  • Article
    | Open Access

    Queen pheromones are used by eusocial insects to regulate all aspects of colony life. Here, Holman et al. compare the effects of queen pheromone on gene expression and splicing in four eusocial insect species, giving insight into the mechanism and evolution of division of reproductive labour.

    • Luke Holman
    • , Heikki Helanterä
    •  & Alexander S. Mikheyev
  • Article
    | Open Access

    Sociality explains substantial variation in ageing across species, but less is known about this relationship within species. Here, the authors show that female dominant Seychelles warblers with helpers at the nest have higher late-life survival and lower telomere attrition and the probability of having helpers increases with age.

    • Martijn Hammers
    • , Sjouke A. Kingma
    •  & David S. Richardson
  • Article
    | Open Access

    Sexual selection is expected to be intensified in non-monogamous mating systems; in birds this might accelerate song evolution. Here, the authors show that across songbirds, polygyny and extra-pair paternity are associated with faster syllable repertoire size evolution and smaller repertoire size, respectively.

    • Kate T. Snyder
    •  & Nicole Creanza
  • Article
    | Open Access

    Group membership can inform individuals’ decisions on whether to cooperate. Here, the authors show how cooperative groups themselves can emerge and change due to use of reputation heuristics (such as “the enemy of a friend is an enemy”), and how this destabilizes cooperation over time.

    • Jörg Gross
    •  & Carsten K. W. De Dreu
  • Article
    | Open Access

    The halictid bee Lasioglossum albipes has both solitary and eusocial individuals, making it a model for social evolution. Here, Kocher et al. identify a genetic variation associated with this social polymorphism, including a variant that can regulate the expression of an autism-associated gene, syntaxin 1a.

    • Sarah D. Kocher
    • , Ricardo Mallarino
    •  & Naomi E. Pierce
  • Article
    | Open Access

    There is some evidence that social context can mediate the progression of cancers. Here, the authors show that Drosophila flies housed in social isolation experienced faster cancer tumor progression than flies in groups, and that flies select for social environments that minimize cancer risk.

    • Erika H. Dawson
    • , Tiphaine P. M. Bailly
    •  & Frederic Mery
  • Article
    | Open Access

    Development may be plastic and influenced by parental care. Here, the authors show that experimental reduction of maternal care in the small carpenter bee leads to extensive changes in gene expression and splicing, minor changes in methylation, and greater offspring aggression and social avoidance.

    • Samuel V. Arsenault
    • , Brendan G. Hunt
    •  & Sandra M. Rehan
  • Article
    | Open Access

    The decoy effect refers to the fact that the presence of a third option can shift people’s preferences between two other options even though the third option is inferior to both. Here, the authors show how the decoy effect can enhance cooperation in a social dilemma, the repeated prisoner’s dilemma.

    • Zhen Wang
    • , Marko Jusup
    •  & Stefano Boccaletti
  • Article
    | Open Access

    The evolution of cooperation depends on social structure, which may evolve in response. Here, Akçay models coevolution between cooperation and social network formation strategies, showing that coevolutionary feedbacks lead cooperation to collapse unless constrained by costs of social connections.

    • Erol Akçay
  • Article
    | Open Access

    Strong positive and strong negative reciprocators reward cooperation and punish defection, respectively, regardless of future benefits. Here, Weber and colleagues demonstrate that dispositions towards strong positive and strong negative reciprocity are not correlated within individuals.

    • Till O. Weber
    • , Ori Weisel
    •  & Simon Gächter
  • Article
    | Open Access

    Humans are known to use social heuristics to make intuitive decisions on whether to cooperate. Here, the authors show with evolutionary simulations that social heuristics can be an adaptive solution to uncertainties about the consequences of cooperation and can greatly increase cooperation levels.

    • Pieter van den Berg
    •  & Tom Wenseleers
  • Article
    | Open Access

    Plants can recognize nearby kin and alter their growth in response. Here, Torices et al. demonstrate that flower production can also be sensitive to social context, with plants producing larger floral displays in the presence of relatives, which may increase attraction of pollinators to the group.

    • Rubén Torices
    • , José M. Gómez
    •  & John R. Pannell
  • Article
    | Open Access

    How do social insect colonies regulate tasks after the developmental stage and in response to changing environments? Here, Crall et al. use automated individual tracking to reveal that task switching after a major colony disturbance helps to maintain collective foraging performance in bumble bees.

    • James D. Crall
    • , Nick Gravish
    •  & Stacey A. Combes
  • Article
    | Open Access

    Live birth may be a precursor for parent-offspring associations and subsequent sociality, but the ubiquity of live birth in mammals and parental care in birds precludes testing the relationship in those clades. Here the authors show that live birth, but not egg attendance, is associated with the evolution of social grouping in squamate reptiles.

    • Ben Halliwell
    • , Tobias Uller
    •  & Geoffrey M. While
  • Article
    | Open Access

    Heterogeneous complex networks tend to be a more realistic representation of social networks than homogenous ones. Here Kleineberg investigates the role of network heterogeneity in the emergence of cooperation in social dilemmas and shows that it can sometimes hinder it.

    • Kaj-Kolja Kleineberg
  • Article
    | Open Access

    Microbes live in communities and exchange metabolites, but the resulting dynamics are poorly understood. Here, the authors study the interplay between metabolite production strategies and population dynamics, and find that complex and unexpected dynamics emerge even in simple microbial economies.

    • Yoav Kallus
    • , John H. Miller
    •  & Eric Libby
  • Article
    | Open Access

    Punishment by peers can enforce social norms, such as contributing to a public good. Here, Abbink and colleagues show that individuals will enforce norms even when contributions reduce the net benefit of the group, resulting in the maintenance of wasteful contributions.

    • Klaus Abbink
    • , Lata Gangadharan
    •  & John Thrasher
  • Article
    | Open Access

    Lab strains of Pseudomonas are model systems for the evolution of cooperation over public goods (iron-scavenging siderophores). Here, Butaitė et al. add ecological and evolutionary insight into this system by showing that cheating and resistance to cheating both shape competition for iron in natural Pseudomonas communities.

    • Elena Butaitė
    • , Michael Baumgartner
    •  & Rolf Kümmerli
  • Article
    | Open Access

    Multicellularity can arise by cells aggregating or remaining connected after cell division. Here, Driscoll and Travisano show that both mechanisms operate in experimentally evolved strains of the yeastKluyveromyces lactis, with transient aggregation facilitating the coexistence of unicellular and multicellular genotypes.

    • William W Driscoll
    •  & Michael Travisano
  • Article
    | Open Access

    Groups of animals tend to solve tasks better than individuals, but it is unclear whether such socially-derived knowledge accumulates over time. Sasaki and Biro demonstrate that homing pigeon flocks progressively improve the efficiency of their routes by culturally accumulating knowledge across generations.

    • Takao Sasaki
    •  & Dora Biro
  • Article
    | Open Access

    Proximity to criticality can be advantageous under changing conditions, but it also entails reduced robustness. Here, the authors analyse fight sizes in a macaque society and find not only that it sits near criticality, but also that the distance from the critical point is tunable through adjustment of individual behaviour and social conflict management.

    • Bryan C. Daniels
    • , David C. Krakauer
    •  & Jessica C. Flack