Beneficial laggards: multilevel selection, cooperative polymorphism and division of labour in threshold public good games

BMC Evolutionary Biology

Research Article

Gergely Boza¹  Szabolcs Számadó² 

[1] Department of Plant Taxonomy and Ecology, Institute of Biology, Eötvös University, Pázmány Péter s. 1/c, H-1117, Budapest, Hungary;Collegium Budapest, Institute for Advanced Study, Szentháromság u. 2, H-1014, Budapest, Hungary;Department of Plant Taxonomy and Ecology, Institute of Biology, Eötvös University, Pázmány Péter s. 1/c, H-1117, Budapest, Hungary;HAS-ELTE Research Group for Theoretical Biology and Ecology, Institute of Biology, Eötvös University and the Hungarian Academy of Sciences, Pázmány Péter s. 1/c, H-1117, Budapest, Hungary;

关键词: Collective Action;    Free Rider;    Killer Whale;    Public Good Game;    Benefit Function;   

DOI  :  10.1186/1471-2148-10-336

 received in 2010-08-05, accepted in 2010-11-02,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe 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.ResultsOur 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.ConclusionsWe 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.

【 授权许可】

CC BY   
© Boza and Számadó; licensee BioMed Central Ltd. 2010