@Article{Haidt07, author = {Jonathan Haidt}, title = {The New Synthesis in Moral Psychology}, journal = {Science}, year = 2007, volume = 316, pages = {998--1002}, annote = {People are selfish, yet morally motivated. Morality is universal, yet culturally variable. Such apparent contradictions are dissolving as research from many disciplines converges on a few shared principles, including the importance of moral intuitions, the socially functional (rather than truth-seeking) nature of moral thinking, and the coevolution of moral minds with cultural practices and institutions that create diverse moral communities. I propose a fourth principle to guide future research: Morality is about more than harm and fairness. More research is needed on the collective and religious parts of the moral domain, such as loyalty, authority, and spiritual purity.} } @article{DeMarzo05, type={Working Paper Series}, title={{Relative Wealth Concerns and Technology Bubbles}}, author={Demarzo, Peter M. and Kaniel, Ron and Kremer, Ilan }, journal={SSRN eLibrary}, year=2005, publisher={SSRN}, keywords={Bubble, technology, relative wealth, Joneses, herding, over-investment}, location={http://ssrn.com/paper=668137}, note={\url{http://ssrn.com/paper=668137}}, language={English} } @article{Arrow63, jstor_articletype = {primary_article}, title = {Uncertainty and the Welfare Economics of Medical Care}, author = {Arrow, Kenneth J.}, journal = {The American Economic Review}, jstor_issuetitle = {}, volume = {53}, number = {5}, jstor_formatteddate = {Dec., 1963}, pages = {941--973}, url = {http://www.jstor.org/stable/1812044}, ISSN = {00028282}, abstract = {}, language = {}, year = {1963}, publisher = {American Economic Association}, copyright = {Copyright ¿ 1963 American Economic Association}, } @Article{CluttonBrock09:Cooperation, author = {Tim Clutton-Brock}, title = {Cooperation Between Non-Kin in Animal Societies}, journal = {Nature}, year = 2009, volume = 462, pages = {51--57}, annote = {Explanations of cooperation between non-kin in animal societies often suggest that individuals exchange resources or services and that cooperation is maintained by reciprocity. But do cooperative interactions between unrelated individuals in non-human animals really resemble exchanges or are they a consequence of simpler mechanisms? Firm evidence of reciprocity in animal societies is rare and many examples of cooperation between non-kin probably represent cases of intra-specific mutualism or manipulation.} } @article{Henrich10:MarketsReligionFairness, author = {Henrich, Joseph and Ensminger, Jean and McElreath, Richard and Barr, Abigail and Barrett, Clark and Bolyanatz, Alexander and Cardenas, Juan Camilo and Gurven, Michael and Gwako, Edwins and Henrich, Natalie and Lesorogol, Carolyn and Marlowe, Frank and Tracer, David and Ziker, John}, title = {Markets, Religion, Community Size, and the Evolution of Fairness and Punishment}, journal = {Science}, volume = {327}, number = {5972}, pages = {1480--1484}, doi = {10.1126/science.1182238}, year = {2010}, abstract = {Large-scale societies in which strangers regularly engage in mutually beneficial transactions are puzzling. The evolutionary mechanisms associated with kinship and reciprocity, which underpin much of primate sociality, do not readily extend to large unrelated groups. Theory suggests that the evolution of such societies may have required norms and institutions that sustain fairness in ephemeral exchanges. If that is true, then engagement in larger-scale institutions, such as markets and world religions, should be associated with greater fairness, and larger communities should punish unfairness more. Using three behavioral experiments administered across 15 diverse populations, we show that market integration (measured as the percentage of purchased calories) positively covaries with fairness while community size positively covaries with punishment. Participation in a world religion is associated with fairness, although not across all measures. These results suggest that modern prosociality is not solely the product of an innate psychology, but also reflects norms and institutions that have emerged over the course of human history.}, eprint = {http://www.sciencemag.org/cgi/reprint/327/5972/1480.pdf} } @article{Hoff10, author = {Hoff, Karla}, title = {Fairness in Modern Society}, journal = {Science}, volume = {327}, number = {5972}, pages = {1467--1468}, doi = {10.1126/science.1188537}, year = {2010}, eprint = {http://www.sciencemag.org/cgi/reprint/327/5972/1467.pdf} } @article{Woolley10012010, author = {Woolley, Anita Williams and Chabris, Christopher F. and Pentland, Alexander and Hashmi, Nada and Malone, Thomas W.}, title = {Evidence for a Collective Intelligence Factor in the Performance of Human Groups}, journal = {Science}, pages = {science.1193147}, doi = {10.1126/science.1193147}, year = {2010}, abstract = {Psychologists have repeatedly shown that a single statistical factor--often called "general intelligence"--emerges from the correlations among people's performance on a wide variety of cognitive tasks. But no one has systematically examined whether a similar kind of "collective intelligence" exists for groups of people. In two studies with 699 individuals, working in groups of two to five, we find converging evidence of a general collective intelligence factor that explains a group's performance on a wide variety of tasks. This "c factor" is not strongly correlated with the average or maximum individual intelligence of group members but is correlated with the average social sensitivity of group members, the equality in distribution of conversational turn-taking, and the proportion of females in the group.}, } @article{Stapel08042011, author = {Stapel, Diederik A. and Lindenberg, Siegwart}, title = {Coping with Chaos: How Disordered Contexts Promote Stereotyping and Discrimination}, volume = 332, number = 6026, pages = {251--253}, year = 2011, doi = {10.1126/science.1201068}, abstract ={Being the victim of discrimination can have serious negative health- and quality-of-life–related consequences. Yet, could being discriminated against depend on such seemingly trivial matters as garbage on the streets? In this study, we show, in two field experiments, that disordered contexts (such as litter or a broken-up sidewalk and an abandoned bicycle) indeed promote stereotyping and discrimination in real-world situations and, in three lab experiments, that it is a heightened need for structure that mediates these effects (number of subjects: between 40 and 70 per experiment). These findings considerably advance our knowledge of the impact of the physical environment on stereotyping and discrimination and have clear policy implications: Diagnose environmental disorder early and intervene immediately.}, eprint = {http://www.sciencemag.org/content/332/6026/251.full.pdf}, journal = {Science} } @article{Freeman01:Libertarians, title = {Illiberal Libertarians: Why Libertarianism Is Not a Liberal View}, author = {Freeman, Samuel}, journal = {Philosophy & Public Affairs}, volume = 30, number = 2, jstor_formatteddate = {Spring, 2001}, pages = {105--151}, url = {http://www.jstor.org/stable/3557960}, ISSN = 00483915, language = {English}, year = 2001, publisher = {Blackwell Publishing}, copyright = {Copyright ¿ 2001 Princeton University Press}, } @Article{Zintzaras10, author = {Zintzaras, Elias and Santos, Mauro and Szathmary, Eors}, title = {Selfishness Versus Functional Cooperation in a Stochastic Protocell Model}, journal = {Journal of Theoretical Biolology}, year = 2010, volume = 267, pages = {605--613}, annote = {How to design an evolvable artificial system capable to Increase in complexity? Although Darwin s theory of evolution by natural selection obviously offers a firm foundation little hope of success seems to be expected from the explanatory adequacy of modern evolutionary theory which does a good job at explaining what has already happened but remains practically helpless at predicting what will occur However the study of the major transitions in evolution clearly suggests that Increases in complexity have occurred on those occasions when the conflicting interests between competing individuals were partly subjugated This immediately raises the issue about levels of selection in evolutionary biology and the idea that multi-level selection scenarios are required for complexity to emerge After analyzing the dynamical behaviour of competing replicators within compartments we show here that a proliferation of differentiated catalysts and/or improvement of catalytic efficiency of ribozymes can potentially evolve in properly designed artificial cells where the strong internal competition between the different species of replicators is somewhat prevented (i e by choosing them with equal probability) Experimental evolution in these systems will likely stand as beautiful examples of artificial adaptive systems and will provide new insights to understand possible evolutionary paths to the evolution of metabolic complexity (C) 2010 Elsevier Ltd All rights reserved} } @Article{Boza10, author = {Boza, Gergely and Szamado, Szabolcs}, title = {Beneficial Laggards: Multilevel Selection, Cooperative Polymorphism and Division of Labour in {T}hreshold {P}ublic {G}ood {G}ames}, journal = {BMC Evol. Biol.}, year = 2010, volume = 10, pages = {Article~336}, annote = {Background: The origin and stability of cooperation is a hot topic in social and behavioural sciences. A complicated conundrum exists as defectors have an advantage over cooperators, whenever cooperation is costly so consequently, not cooperating pays off. In addition, the discovery that humans and some animal populations, such as lions, are polymorphic, where cooperators and defectors stably live together - while defectors are not being punished-, is even more puzzling. Here we offer a novel explanation based on a Threshold Public Good Game (PGG) that includes the interaction of individual and group level selection, where individuals can contribute to multiple collective actions, in our model group hunting and group defense. Results: Our results show that there are polymorphic equilibria in Threshold PGGs; that multi-level selection does not select for the most cooperators per group but selects those close to the optimum number of cooperators (in terms of the Threshold PGG). In particular for medium cost values division of labour evolves within the group with regard to the two types of cooperative actions (hunting vs. defense). Moreover we show evidence that spatial population structure promotes cooperation in multiple PGGs. We also demonstrate that these results apply for a wide range of non-linear benefit function types. Conclusions: We demonstrate that cooperation can be stable in Threshold PGG, even when the proportion of so called free riders is high in the population. A fundamentally new mechanism is proposed how laggards, individuals that have a high tendency to defect during one specific group action can actually contribute to the fitness of the group, by playing part in an optimal resource allocation in Threshold Public Good Games. In general, our results show that acknowledging a multilevel selection process will open up novel explanations for collective actions.} } @Article{Rainey10, author = {Rainey, Paul B. and Kerr, Benjamin}, title = {Cheats as First Propagules: A New Hypothesis for the Evolution of Individuality During the Transition from Single Cells to Multicellularity}, journal = {Bioessays}, year = 2010, volume = 32, pages = {872--880}, annote = {The emergence of individuality during the evolutionary transition from single cells to multicellularity poses a range of problems. A key issue is how variation in lower-level individuals generates a corporate (collective) entity with Darwinian characteristics. Of central importance to this process is the evolution of a means of collective reproduction, however, the evolution of a means of collective reproduction is not a trivial issue, requiring careful consideration of mechanistic details. Calling upon observations from experiments, we draw attention to proto-life cycles that emerge via unconventional routes and that transition, in single steps, individuality to higher levels. One such life cycle arises from conflicts among levels of selection and invokes cheats as a primitive germ line: it lays the foundation for collective reproduction, the basis of a self-policing system, the selective environment for the emergence of development, and hints at a plausible origin for a soma/germ line distinction.} } @Article{Pigliucci10, author = {Pigliucci, Massimo}, title = {Okasha's Evolution and the Levels of Selection: Toward a Broader Conception of Theoretical Biology}, journal = {Biol. Philos.}, year = 2010, volume = 25, pages = {405--415}, annote = {The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha's book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that sees scientists and philosophers coming together to build a broadened concept of "theory" through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome.} } @Article{Okasha09, author = {Okasha, Samir}, title = {Individuals, Groups, Fitness and Utility: Multi-Level Selection Meets Social Choice Theory}, journal = {Biol. Philos.}, year = 2009, volume = 24, pages = {561--584}, annote = {In models of multi-level selection, the property of Darwinian fitness is attributed to entities at more than one level of the biological hierarchy, e. g. individuals and groups. However, the relation between individual and group fitness is a controversial matter. Theorists disagree about whether group fitness should always, or ever, be defined as total (or average) individual fitness. This paper tries to shed light on the issue by drawing on work in social choice theory, and pursuing an analogy between fitness and utility. Social choice theorists have long been interested in the relation between individual and social utility, and have identified conditions under which social utility equals total (or average) individual utility. These ideas are used to shed light on the biological problem.} } @Article{Pigliucci09, author = {Pigliucci, Massimo}, title = {{S}amir {O}kasha: {E}volution and the Levels of Selection}, journal = {Biol. Philos.}, year = 2009, volume = 24, pages = {551--560}, annote = {The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha's book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that sees scientists and philosophers coming together to build a broadened concept of "theory" through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome.} } @Article{Egas08, author = {Egas, Martijn and Riedl, Arno}, title = {Proc. R. Soc. B.}, journal = {The Economics of Altruistic Punishment and the Maintenance of Cooperation}, year = 2008, volume = 275, pages = {871--878}, annote = {Explaining the evolution and maintenance of cooperation among unrelated individuals is one of the fundamental problems in biology and the social sciences. Recent findings suggest that altruistic punishment is an important mechanism maintaining cooperation among humans. We experimentally explore the boundaries of altruistic punishment to maintain cooperation by varying both the cost and the impact of punishment, using an exceptionally extensive subject pool. Our results show that cooperation is only maintained if conditions for altruistic punishment are relatively favourable: low cost for the punisher and high impact on the punished. Our results indicate that punishment is strongly governed by its cost-to-impact ratio and that its effect on cooperation can be pinned down to one single variable: the threshold level of free-riding that goes unpunished. Additionally, actual pay-offs are the lowest when altruistic punishment maintains cooperation, because the pay-off destroyed through punishment exceeds the gains from increased cooperation. Our results are consistent with the interpretation that punishment decisions come from an amalgam of emotional response and cognitive cost-impact analysis and suggest that altruistic punishment alone can hardly maintain cooperation under multi-level natural selection. Uncovering the workings of altruistic punishment as has been done here is important because it helps predicting under which conditions altruistic punishment is expected to maintain cooperation.} } @Article{Helanterae06, author = {Helanter{\"a}, H.}, title = {The Unity That Does Not Exist---A Review of {A.} {B}urt \& {R.} {T}rivers 2006: {G}enes in {C}onflict}, journal = {J. Evol. Bol.}, year = 2006, volume = 19, pages = {2067--2070}, annote = {Organisms harbour several genetic elements with the potential to act selfishly, and thus undermine the fitness of the organism as a whole. In their book 'Genes in conflict', Austin Burt and Robert Trivers thoroughly review evolution and molecular biology of such selfish genetics elements, and set them in a kin selection framework. In this review I set their views in a larger multi-level selection framework, and consider potential problems in the study of selfish genetics elements.} } @Article{Okasha05, author = {Okasha, Samir}, title = {Altruism, Group Selection and Correlated Interaction}, journal = {Brit. J. Phil. Sci.}, year = 2005, volume = 56, pages = {703--725}, annote = {Group selection is one acknowledged mechanism for the evolution of altruism. It is well known that for altruism to spread by natural selection, interactions must be correlated; that is, altruists must tend to associate with one another. But does group selection itself require correlated interactions? Two possible arguments for answering this question affirmatively are explored. The first is a bad argument, for it rests on a product/process confusion. The second is a more subtle argument, whose validity (or otherwise) turns on issues concerning the meaning of multi-level selection and how it should be modelled. A cautious defence of the second argument is offered. 1 Introduction 2 Multi-level selection and the evolution of altruism 3 Price's equation and multi-level selection 4 Contextual analysis and multi-level selection 5 The neighbour approach 6 Recapitulation and conclusion.} } @Article{Okasha04, author = {Okasha, Samir}, title = {Multi-Level Selection, Covariance and Contextual Analysis}, journal = {Brit. J. Phil. Sci.}, year = 2004, volume = 55, pages = {481--504}, annote = {Two alternative statistical approaches to modelling multi-level selection in nature, both found in the contemporary biological literature, are contrasted. The simple covariance approach partitions the total selection differential on a phenotypic character into within-group and between-group components, and identifies the change due to group selection with the latter. The contextual approach partitions the total selection differential into different components, using multivariate regression analysis. The two approaches have different implications for the question of what constitutes group selection and what does not. I argue that the contextual approach is theoretically preferable. This has important implications for a number of issues in the philosophical debate about the levels of selection.} } @Article{Bowles04, author = {Bowles, Samuel and Gintis, Herbert}, title = {The Evolution of Strong Reciprocity: Cooperation in Heterogeneous Populations}, journal = {Theor. Population Biol.}, year = 2004, volume = 65, pages = {17--28}, annote = {How do human groups maintain a high level of cooperation despite a low level of genetic relatedness among group members? We suggest that many humans have a predisposition to punish those who violate group-beneficial norms, even when this imposes a fitness cost on the punisher. Such altruistic punishment is widely observed to sustain high levels of cooperation in behavioral experiments and in natural settings. We offer a model of cooperation and punishment that we call strong reciprocity: where members of a group benefit from mutual adherence to a social norm, strong reciprocators obey the norm and punish its violators, even though as a result they receive lower payoffs than other group members, such as selfish agents who violate the norm and do not punish, and pure cooperators who adhere to the norm but free-ride by never punishing. Our agent-based simulations show that, under assumptions approximating likely human environments over the 100,000 years prior to the domestication of animals and plants, the proliferation of strong reciprocators when initially rare is highly likely, and that substantial frequencies of all three behavioral types can be sustained in a population. As a result, high levels of cooperation are sustained. Our results do not require that group members be related or that group extinctions occur. (C) 2003 Published by Elsevier Inc.} } @Article{Gintis03, author = {Gintis, Herbert}, title = {The Hitchhiker's Guide to Altruism: Gene-Culture Coevolution, and the Internalization of Norms}, journal = {J. Theor. Biol.}, year = 2003, volume = 220, pages = {407--418}, annote = {An internal norm is a pattern of behavior enforced in part by internal sanctions, such as shame, guilt and loss of self-esteem, as opposed to purely external sanctions, such as material rewards and punishment. The ability to internalize norms is widespread among humans, although in some so-called "sociopaths", this capacity is diminished or lacking. Suppose there is one genetic locus that controls the capacity to internalize norms. This model shows that if an internal norm is fitness enhancing, then for plausible patterns of socialization, the allele for internalization of norms is evolutionarily stable. This framework can be used to model Herbert Simon's (1990) explanation of altruism, showing that altruistic norms can "hitchhike" on the general tendency of internal norms to be personally fitness-enhancing. A multi-level selection, gene-culture coevolution argument then explains why individually fitness-reducing internal norms are likely to be prosocial as opposed to socially harmful. (C) 2003 Elsevier Science Ltd. All rights reserved.} } @Article{Kerr02, author = {Kerr, Benjamin and Godfrey-Smith, Peter}, title = {Individualist and Multi-Level Perspectives on Selection in Structured Populations}, journal = {Biol. Philos.}, year = 2002, volume = 17, pages = {477--517}, annote = {Recent years have seen a renewed debate over the importance of group selection, especially as it relates to the evolution of altruism. One feature of this debate has been disagreement over which kinds of processes should be described in terms of selection at multiple levels, within and between groups. Adapting some earlier discussions, we present a mathematical framework that can be used to explore the exact relationships between evolutionary models that do, and those that do not, explicitly recognize biological groups as fitness-bearing entities. We show a fundamental set of mathematical equivalences between these two kinds of models, one of which applies a form of multi-level selection theory and the other being a form of "individualism." However, we also argue that each type of model can have heuristic advantages over the other. Indeed, it can be positively useful to engage in a kind of back-and-forth switching between two different perspectives on the evolutionary role of groups. So the position we defend is a "gestalt-switching pluralism".} } @Article{Kerr02a, author = {Kerr, Benjamin and Godfrey-Smith, Peter}, title = {On {P}rice's Equation and Average Fitness}, journal = {Biol. Philos.}, year = 2002, volume = 17, pages = {551--565}, annote = {A number of recent discussions have argued that George Price's equation for representing evolutionary change is a powerful and illuminating tool, especially in the context of debates about multiple levels of selection. Our paper dissects Price's equation in detail, and compares it to another statistical tool: the calculation and comparison of average fitnesses. The relations between Price's equation and equations for evolutionary change using average fitness are closer than is sometimes supposed. The two approaches achieve a similar kind of statistical summary of one generation of change, and they achieve this via a similar loss of information about the underlying fitness structure.} } @Article{Nachtomy02, author = {Nachtomy, Ohad and Shavit, Ayelet and Smith, Justin}, title = {Leibnizian Organisms, Nested Individuals, and Units of Selection}, journal = {Theory Biosci.}, year = 2002, volume = 121, pages = {205--230}, annote = {Leibniz developed a new notion of individuality, according to which individuals are nested one within another, thereby abandoning the Aristotelian formula at the heart of substantialist metaphysics, 'one body, one substance'. On this model, the level of individuality is determined by the degree of activity, and partly defined by its relations with other individuals. In this article, we show the importance of this new notion of individuality for some persisting questions in theoretical biology. Many evolutionary theorists presuppose a model of individuality that will eventually reduce to spatiotemporal mechanisms, and some still look for an exclusive level or function to determine a unit of selection. In recent years, a number of alternatives to these exclusive approaches have emereged, and no consensus can be foreseen. It is for this reason that we propose the model of nested individuals. This model supports pluralistic multi-level selection and rejects an exclusive level or function for a unit of selection. Since activity is essential to the unity of an individual, this model focuses on integrating processes of interaction and replication instead of choosing between them. In addition, the model of nested individuals may also be seen as a distinct perspective among the various alternative models for the unit of selection. This model stresses activity and pluralism: it accepts simultaneuous co-existence of individuals at different levels, nested one within the other. Our aim in this article is to show now a chapter of the history of metaphysics may be fruitfully brought to bear on the current debate over the unit of selection in evolutionary biology.} } @Article{Canals98, author = {Canals, Jos{\'e} and Vega-Redondo, Fernando}, title = {Multi-Level Evolution in Population Games}, journal = {Int. J. Game Theory}, year = 1998, volume = 27, pages = {21--35}, annote = {In this paper, we analyze a generalization of the evolutionary model of Kandori, Mailath, & Rob (1993) where the population is partitioned into groups and evolution takes place "in parallel" at the following two levels: (i) within groups, at the lower level; among groups, at the higher one. Unlike in their context, efficiency considerations always overcome those of risk-dominance in the process of selecting the long-run equilibrium. This provides an explicitly dynamic basis for a conclusion reminiscent of those put forward in the biological literature by the so-called theories group selection. From a normative viewpoint, it suggests the potential importance of "decentralization", here understood as local and independent interaction.} } @Article{Simon10, author = {Simon, Burton}, title = {A Dynamical Model of Two-Level Selection}, journal = {Evol. Ecol. Res.}, year = 2010, volume = 12, pages = {555--588}, annote = {Question: How do continuous-time evolutionary trajectories of two-level selection behave? Approach: Construct and solve a dynamical model of two-level selection capable of predicting evolutionary trajectories and equilibrium configurations. Mathematical methods: Evolutionary birth-death processes, simulation, large population asymptotics, numerical solutions of hyperbolic PDEs. Key assumptions: Environment composed of distinct groups of individuals. Individuals' birth and death rates are differentiable functions of the state of the environment. Groups' fissioning and extinction rates are integrable functions of the state of the environment. Main results: A continuous-time, discrete-state, stochastic model of two-level selection that can be simulated exactly. A continuous-time, continuous-state, deterministic (PDE) model of two-level selection that can be solved numerically. A mathematical connection between the stochastic and deterministic models. Equilibrium configurations of the environment in models of the evolution of cooperation by two-level selection often consist of complicated mixtures of groups of varying sizes, ages, and levels of cooperation.} } @Article{Goodnight11, author = {Goodnight, Charles J.}, title = {Evolution in Metacommunities}, journal = {Phil. Trans. R. Soc. B}, year = 2011, volume = 366, pages = {1401--1409}, annote = {A metacommunity can be defined as a set of communities that are linked by migration, and extinction and recolonization. In metacommunities, evolution can occur not only by processes that occur within communities such as drift and individual selection, but also by among-community processes, such as divergent selection owing to random differences among communities in species composition, and group and community-level selection. The effect of these among-community-level processes depends on the pattern of migration among communities. Migrating units may be individuals (migrant pool model), groups of individuals (single-species propagule pool model) or multi-species associations (multi-species propagule pool model). The most interesting case is the multi-species propagule pool model. Although this pattern of migration may a priori seem rare, it becomes more plausible in small well-defined 'communities' such as symbiotic associations between two or a few species. Theoretical models and experimental studies show that community selection is potentially an effective evolutionary force. Such evolution can occur either through genetic changes within species or through changes in the species composition of the communities. Although laboratory studies show that community selection can be important, little is known about how important it is in natural populations.} } @Article{Nunney85a, author = {Len Nunney}, title = {Group Selection, Altruism, and Structured-Deme Models}, journal = {American Naturalist}, year = 1985, volume = 126, pages = {212--230} } @Article{Nunney85b, author = {Len Nunney}, title = {Female-Biased Sex Ratios: Individual or Group Selection?}, journal = {Evolution}, year = 1985, volume = 39, pages = {349--361} } @Article{Lion11, author = {S{\'e}bastien Lion and Vincent A. A. Jansen and Troy Day}, title = {Evolution in Structured Populations: Beyond the Kin Versus Group Debate}, journal = {Trends Ecol. Evol.}, year = 2011, volume = 26, pages = {193--201}, annote = {Much of the literature on social evolution is pervaded by the old debate about the relative merits of kin and group selection. In this debate, the biological interpretation of processes occurring in real populations is often conflated with the mathematical methodology used to describe these processes. Here, we highlight the distinction between the two by placing this discussion within the broader context of evolution in structured populations. In this review we show that the current debate overlooks important aspects of the interplay between genetic and demographic structuring, and argue that a continued focus on the relative merits of kin versus group selection distracts attention from moving the field forward.} } @Article{Leigh09, author = {Leigh, E. G., Jr.}, title = {The Group Selection Controversy}, journal = {J. Evol. Biol.}, year = 2009, volume = 23, pages = {6--19}, annote = {Many thought Darwinian natural selection could not explain altruism. This error led Wynne-Edwards to explain sustainable exploitation in animals by selection against overexploiting groups. Williams riposted that selection among groups rarely overrides within-group selection. Hamilton showed that altruism can evolve through kin selection. How strongly does group selection influence evolution? Following Price, Hamilton showed how levels of selection interact: group selection prevails if Hamilton's rule applies. Several showed that group selection drove some major evolutionary transitions. Following Hamilton's lead, Queller extended Hamilton's rule, replacing genealogical relatedness by the regression on an actor's genotypic altruism of interacting neighbours' phenotypic altruism. Price's theorem shows the generality of Hamilton's rule. All instances of group selection can be viewed as increasing inclusive fitness of autosomal genomes. Nonetheless, to grasp fully how cooperation and altruism evolve, most biologists need more concrete concepts like kin selection, group selection and selection among individuals for their common good. } } @Article{Platt09, author = {Thomas G. Platt and James D. Bever}, title = {Kin Competition and the Evolution of Cooperation}, journal = {Trends Ecol. Evol.}, year = 2009, volume = 24, pages = {370--377}, annote = {Kin and multilevel selection theories predict that genetic structure is required for the evolution of cooperation. However, local competition among relatives can limit cooperative benefits, antagonizing the evolution of cooperation. We show that several ecological factors determine the extent to which kin competition constrains cooperative benefits. In addition, we argue that cooperative acts that expand local carrying capacity are less constrained by kin competition than other cooperative traits, and are therefore more likely to evolve. These arguments are particularly relevant to microbial cooperation, which often involves the production of public goods that promote population expansion. The challenge now is to understand how an organism's ecology influences how much cooperative groups contribute to future generations and thereby the evolution of cooperation.} } @Article{Rankin07, author = {Daniel J. Rankin and Katja Bargum and Hanna Kokko}, title = {The Tragedy of the Commons in Evolutionary Biology}, journal = {Trends Ecol. Evol.}, year = 2007, volume = 22, pages = {643--651}, annote = {Garrett Hardin's tragedy of the commons is an analogy that shows how individuals driven by self-interest can end up destroying the resource upon which they all depend. The proposed solutions for humans rely on highly advanced skills such as negotiation, which raises the question of how non-human organisms manage to resolve similar tragedies. In recent years, this question has promoted evolutionary biologists to apply the tragedy of the commons to a wide range of biological systems. Here, we provide tools to categorize different types of tragedy and review different mechanisms, including kinship, policing and diminishing returns that can resolve conflicts that could otherwise end in tragedy. A central open question, however, is how often biological systems are able to resolve these scenarios rather than drive themselves extinct through individual-level selection favouring self-interested behaviours.} } @Article{Taylor07:Dilemma, author = {Christine Taylor and Martin A. Nowak}, title = {Transforming the Dilemma}, journal = {Evolution}, year = 2007, volume = 61, pages = {2281--2292}, annote = {How does natural selection lead to cooperation between competing individuals ? The Prisoner's Dilemma captures the essence of this problem. Two players can either cooperate or defect. The payoff for mutual cooperation, R, is greater than the payoff for mutual defection, P. But a defector versus a cooperator receives the highest payoff, T, where as the cooperator obtains the lowest payoff, S. Hence, the Prisoner's Dilemma is defined by the payoff ranking T > R > P > S. In a well-mixed population, defectors always have a higher expected payoff than cooperators, and therefore natural selection favors defectors. The evolution of cooperation requires specific mechanisms. Here we discuss five mechanisms for the evolution of cooperation: direct reciprocity, indirect reciprocity, kin selection, group selection, and network reciprocity (or graph selection). Each mechanism leads to a transformation of the Prisoner's Dilemma payoff matrix. From the transformed matrices, we derive the fundamental conditions for the evolution of cooperation. The transformed matrices can be used in standard frameworks of evolutionary dynamics such as the replicator equation or stochastic processes of game dynamics in finite populations.} } @Article{West07, author = {Stuart A. West and Stephen P. Diggle and Angus Buckling and Andy Gardner and Ashleigh S. Griffin}, title = {The Social Lives of Microbes}, journal = {Ann. Rev. Evol. Ecol. Systematics}, year = 2007, volume = 38, pages = {53--77}, annote = {Our understanding of the social lives of microbes has been revolutionized over the past 20 years. It used to be assumed that bacteria and other microorganisms lived relatively independent unicellular lives, without the cooperative behaviors that have provoked so much interest in mammals, birds, and insects. However, a rapidly expanding body of research has completely overturned this idea, showing that microbes indulge in a variety of social behaviors involving complex systems of cooperation, communication, and synchronization. Work in this area has already provided some elegant experimental tests of social evolutionary theory, demonstrating the importance of factors such as relatedness, kin discrimination, competition between relatives, and enforcement of cooperation. Our aim here is to review these social behaviors, emphasizing the unique opportunities they offer for testing existing evolutionary theory as well as highlighting the novel theoretical problems that they pose.} } @Article{Lehmann06, author = {L. Lehmann and L. Keller}, title = {The Evolution of Cooperation and Altruism---A General Framework and a Classification of Models}, journal = {J. Evol. Biol.}, year = 2006, volume = 19, pages = {1365--1376}, annote = {One of the enduring puzzles in biology and the social sciences is the origin and persistence of intraspecific cooperation and altruism in humans and other species. Hundreds of theoretical models have been proposed and there is much confusion about the relationship between these models. To clarify the situation, we developed a synthetic conceptual framework that delineates the conditions necessary for the evolution of altruism and cooperation. We show that at least one of the four following conditions needs to be fulfilled: direct benefits to the focal individual performing a cooperative act; direct or indirect information allowing a better than random guess about whether a given individual will behave cooperatively in repeated reciprocal interactions; preferential interactions between related individuals; and genetic correlation between genes coding for altruism and phenotypic traits that can be identified. When one or more of these conditions are met, altruism or cooperation can evolve if the cost-to-benefit ratio of altruistic and cooperative acts is greater than a threshold value. The cost-to-benefit ratio can be altered by coercion, punishment and policing which therefore act as mechanisms facilitating the evolution of altruism and cooperation. All the models proposed so far are explicitly or implicitly built on these general principles, allowing us to classify them into four general categories.} } @Article{Wilson83, author = {David Sloan Wilson}, title = {The Group Selection Controversy: History and Current Status}, journal = {Ann. Rev. Ecol. Systematics}, year = 1983, volume = 14, pages = {159--187} } @Article{West07a, author = {S. A. West and A. S. Griffin and A. Gardner}, title = {Social Semantics: Altruism, Cooperation, Mutualism, Strong Reciprocity and Group Selection}, journal = {J. Evol. Biol.}, year = 2007, volume = 20, pages = {415--432}, annote = {From an evolutionary perspective, social behaviours are those which have fitness consequences for both the individual that performs the behaviour, and another individual. Over the last 43 years, a huge theoretical and empirical literature has developed on this topic. However, progress is often hindered by poor communication between scientists, with different people using the same term to mean different things, or different terms to mean the same thing. This can obscure what is biologically important, and what is not. The potential for such semantic confusion is greatest with interdisciplinary research. Our aim here is to address issues of semantic confusion that have arisen with research on the problem of cooperation. In particular, we: (i) discuss confusion over the terms kin selection, mutualism, mutual benefit, cooperation, altruism, reciprocal altruism, weak altruism, altruistic punishment, strong reciprocity, group selection and direct fitness; (ii) emphasize the need to distinguish between proximate (mechanism) and ultimate (survival value) explanations of behaviours. We draw examples from all areas, but especially recent work on humans and microbes. } } @Article{Wilson08, author = {D. S. Wilson}, title = {Social Semantics: Toward a Genuine Pluralism in the Study of Social Behaviour}, journal = {J. Evol. Biol.}, year = 2008, volume = 21, pages = {368--373}, annote = {Pluralism is the coexistence of equivalent theoretical frameworks, either because they are historically entrenched or because they achieve separate insights by viewing the same process in different ways. A recent article by West et al. [Journal of Evolutionary Biology (2007) vol. 20, 415-432] attempts to classify the many equivalent frameworks that have been developed to study the evolution of social behaviour. This article addresses shortcomings in the West et al.'s article, especially with respect to multilevel selection, in a common effort to maximize the benefits of pluralism while minimizing the semantic costs.} } @Article{West08, author = {S. A. West and A. S. Griffin and A. Gardner}, title = {Social Semantics: How Useful Has Group Selection Been?}, journal = {J. Evol. Biol.}, year = 2008, volume = 21, pages = {374--385}, annote = {In our social semantics review ( J. Evol. Biol., 2007, 415-432), we discussed some of the misconceptions and sources of confusion associated with group selection. Wilson (2007, this issue) claims that we made three errors regarding group selection. Here, we aim to expand upon the relevant points from our review in order to refute this claim. The last 45 years of research provide clear evidence of the relative use of the kin and group selection approaches. Kin selection methodologies are more tractable, allowing the construction of models that can be applied more easily to specific biological examples, including those chosen by Wilson to illustrate the utility of the group selection approach. In contrast, the group selection approach is not only less useful, but also appears to frequently have negative consequences by fostering confusion that leads to wasted effort. More generally, kin selection theory allows the construction of a unified conceptual overview that can be applied across all taxa, whereas there is no formal theory of group selection.} } @Article{Hamilton64a, author = {Hamilton, W. D.}, title = {The Genetical Evolution of Social Behavior. {I}}, journal = {J. Theor. Biol.}, year = 1964, volume = 7, pages = {1--16} } @Article{Hamilton64b, author = {Hamilton, W. D.}, title = {The Genetical Evolution of Social Behavior. {II}}, journal = {J. Theor. Biol.}, year = 1964, volume = 7, pages = {17--52} } @Article{Lion09, author = {S. Lion and S. Gandon}, title = {Habitat Saturation and the Spatial Evolutionary Ecology of Altruism}, journal = {J. Evol. Biol.}, year = 2009, volume = 22, pages = {1487--1502}, annote = {Under which ecological conditions should individuals help their neighbours? We investigate the effect of habitat saturation on the evolution of helping behaviours in a spatially structured population. We combine the formalisms of population genetics and spatial moment equations to tease out the effects of various physiological (direct benefits and costs of helping) and ecological parameters (such as the density of empty sites) on the selection gradient on helping. Our analysis highlights the crucial importance of demography for the evolution of helping behaviours. It shows that habitat saturation can have contrasting effects, depending on the form of competition (direct vs. indirect competition) and on the conditionality of helping. In our attempt to bridge the gap between spatial ecology and population genetics, we derive an expression for relatedness that takes into account both habitat saturation and the spatial structure of genetic variation. This analysis helps clarify discrepancies in the results obtained by previous theoretical studies. It also provides a theoretical framework taking into account the interplay between demography and kin selection, in which new biological questions can be explored.} } @Article{Wilson77, author = {David Sloan Wilson}, title = {Structured Demes and the Evolution of Group-Advantageous Traits}, journal = {American Naturalist}, year = 1977, volume = 111, pages = {157--185}, annote = {1. Most organisms interact with a set of neighbors smaller than the deme (its trait group). Demes therefore are not only a population of individuals but also a population of groups (structured demes). 2. Trait groups vary in their composition. The minimum variance to be expected is that arising from a binomial distribution. Most populations have a higher variance than this due to (a) differential interactions with the environment and (b) the effects of reproduction inside the trait groups. 3. As a consequence of this variation, an individual on the average experiences its own "type" in a greater frequency than actually exists in the deme. Its behaviors are therefore directed differentially toward fellow types, and this is the fundamental requirement for the evolution of altruism. 4. Models are presented for warning cries and other donor-recipient relations, resource notification, the evolution of prudence in exploitation and interference competition, and the effect of differential trait-group extinction. In all cases evolution in structured demes differs from traditional individual-selection models. Individual selection corresponds to the case where there is zero variance among trait groups, that is, complete homogeneity. 5. The "threshold" variance permitting the evolution of altruism (negative fitness change to the donor) is that arising from a binomial distribution. As this is the minimum to be expected in nature, this theory predicts that at least weakly altruistic behavior should be a common occurrence (but see [9]). 6. If a population is overexploiting its resource, a decrease in feeding rate through interference may be selected for given any trait-group variation. 7. When trait groups are composed entirely of siblings (i.e., kin groups), the model is mathematically equivalent to kin selection. 8. As well as increasing population fitness, social systems may also evolve an "immunity" against group-detrimental types. 9. If a given group-advantageous effect can be accomplished through both altruistic and selfish mechanisms, the selfish mechanism will be selected. A paucity of altruistic behaviors may signify that it is usually possible to create the same result selfishly--not that altruism "cannot" be selected for} } @Article{Fletcher09, author = {Jeffrey A. Fletcher and Michael Doebeli}, title = {A Simple and General Explanation for the Evolution of Altruism}, journal = {Proc. Roy. Soc. B}, year = 2009, volume = 276, pages = {13--19}, annote = {We present a simple framework that highlights the most fundamental requirement for the evolution of altruism: assortment between individuals carrying the cooperative genotype and the helping behaviours of others with which these individuals interact. We partition the fitness effects on individuals into those due to self and those due to the \u2018interaction environment\u2019, and show that it is the latter that is most fundamental to understanding the evolution of altruism. We illustrate that while kinship or genetic similarity among those interacting may generate a favourable structure of interaction environments, it is not a fundamental requirement for the evolution of altruism, and even suicidal aid can theoretically evolve without help ever being exchanged among genetically similar individuals. Using our simple framework, we also clarify a common confusion made in the literature between alternative fitness accounting methods (which may equally apply to the same biological circumstances) and unique causal mechanisms for creating the assortment necessary for altruism to be favoured by natural selection.} } @Article{Lion09a, author = {S{\'e}bastien Lion}, title = {Relatedness in Spatially Structured Populations with Empty Sites: An Approach Based on Spatial Moment Equations}, journal = {J. Theor. Biol.}, year = 2009, volume = 260, pages = {121--131}, annote = {Taking into account the interplay between spatial ecological dynamics and selection is a major challenge in evolutionary ecology. Although inclusive fitness theory has proven to be a very useful tool to unravel the interactions between spatial genetic structuring and selection, applications of the theory usually rely on simplifying demographic assumptions. In this paper, I attempt to bridge the gap between spatial demographic models and kin selection models by providing a method to compute approximations for relatedness coefficients in a spatial model with empty sites. Using spatial moment equations, I provide an approximation of nearest-neighbour relatedness on random regular networks, and show that this approximation performs much better than the ordinary pair approximation. I discuss the connection between the relatedness coefficients I define and those used in population genetics, and sketch some potential extensions of the theory.} } @article{Hirose22072011, author = {Hirose, Shigenori and Benabentos, Rocio and Ho, Hsing-I and Kuspa, Adam and Shaulsky, Gad}, title = {Self-Recognition in Social Amoebae Is Mediated by Allelic Pairs of Tiger Genes}, volume = 333, number = 6041, pages = {467-470}, year = 2011, journal = {Science}, doi = {10.1126/science.1203903}, abstract ={Free-living cells of the social amoebae Dictyostelium discoideum can aggregate and develop into multicellular fruiting bodies in which many die altruistically as they become stalk cells that support the surviving spores. Dictyostelium cells exhibit kin discrimination—a potential defense against cheaters, which sporulate without contributing to the stalk. Kin discrimination depends on strain relatedness, and the polymorphic genes tgrB1 and tgrC1 are potential components of that mechanism. Here, we demonstrate a direct role for these genes in kin discrimination. We show that a matching pair of tgrB1 and tgrC1 alleles is necessary and sufficient for attractive self-recognition, which is mediated by differential cell-cell adhesion. We propose that TgrB1 and TgrC1 proteins mediate this adhesion through direct binding. This system is a genetically tractable ancient model of eukaryotic self-recognition.}, } @Article{Leadbeater11, author = {Ellouise Leadbeater b*mand Jonathan M. Carruthers and Jonathan P. Green and Neil S. Rosser and Jeremy Field}, title = {Nest Inheritance Is the Missing Source of Direct Fitness in a Primitively Eusocial Insect}, journal = {Science}, year = 2011, volume = 333, number = 6044, pages = {874--876}, abstract= {Animals that cooperate with nonrelatives represent a challenge to inclusive fitness theory, unless cooperative behavior is shown to provide direct fitness benefits. Inheritance of breeding resources could provide such benefits, but this route to cooperation has been little investigated in the social insects. We show that nest inheritance can explain the presence of unrelated helpers in a classic social insect model, the primitively eusocial wasp Polistes dominulus. We found that subordinate helpers produced more direct offspring than lone breeders, some while still subordinate but most after inheriting the dominant position. Thus, while indirect fitness obtained through helping relatives has been the dominant paradigm for understanding eusociality in insects, direct fitness is vital to explain cooperation in P. dominulus.} } @Article{Kiers11, author = {E. Toby Kiers and Marie Duhamel and Yugandhar Beesetty and Jerry A. Mensah and Oscar Franken and Erik Verbruggen and Carl R. Fellbaum and George A. Kowalchuk and Miranda M. Hart and Alberto Bago and Todd M. Palmer and Stuart A. West and Philippe Vandenkoornhuyse and Jan Jansa and Heike B\"ucking}, title = {Reciprocal Rewards Stabilize Cooperation in the Mycorrhizal Symbiosis}, journal = {Science}, year = 2011, volume = 333, number = 6044, pages = {880--882}, annote = {Plants and their arbuscular mycorrhizal fungal symbionts interact in complex underground networks involving multiple partners. This increases the potential for exploitation and defection by individuals, raising the question of how partners maintain a fair, two-way transfer of resources. We manipulated cooperation in plants and fungal partners to show that plants can detect, discriminate, and reward the best fungal partners with more carbohydrates. In turn, their fungal partners enforce cooperation by increasing nutrient transfer only to those roots providing more carbohydrates. On the basis of these observations we conclude that, unlike many other mutualisms, the symbiont cannot be \u201censlaved.\u201d Rather, the mutualism is evolutionarily stable because control is bidirectional, and partners offering the best rate of exchange are rewarded.} } @Article{Johnson11:Overconfidence, author = {Johnson, Dominic D.P. and Fowler, James H.}, title = {The evolution of Overconfidence}, journal = {Nature}, year = 2011, volume = 477, number = 7364, pages = {317--320}, annote = {Confidence is an essential ingredient of success in a wide range of domains ranging from job performance and mental health to sports, business and combat1, 2, 3, 4. Some authors have suggested that not just confidence but overconfidence\u2014believing you are better than you are in reality\u2014is advantageous because it serves to increase ambition, morale, resolve, persistence or the credibility of bluffing, generating a self-fulfilling prophecy in which exaggerated confidence actually increases the probability of success3, 4, 5, 6, 7, 8. However, overconfidence also leads to faulty assessments, unrealistic expectations and hazardous decisions, so it remains a puzzle how such a false belief could evolve or remain stable in a population of competing strategies that include accurate, unbiased beliefs. Here we present an evolutionary model showing that, counterintuitively, overconfidence maximizes individual fitness and populations tend to become overconfident, as long as benefits from contested resources are sufficiently large compared with the cost of competition. In contrast, unbiased strategies are only stable under limited conditions. The fact that overconfident populations are evolutionarily stable in a wide range of environments may help to explain why overconfidence remains prevalent today, even if it contributes to hubris, market bubbles, financial collapses, policy failures, disasters and costly wars9, 10, 11, 12, 13.} }