Eusociality and Cooperation

Abstract

AbstractThe evolution of eusociality, here defined as the emergence of societies with reproductive division of labour and cooperative brood care, was first seen as a challenge to Darwin's theory of evolution by natural selection. Why should individuals permanently forgo direct reproduction to help other individuals to reproduce? Kin selection, the indirect transmission of genes through relatives, is the key process explaining the evolution of permanently nonreproductive helpers. However, in some taxa helpers delay reproduction until a breeding opportunity becomes available. Overall, eusociality evolved when ecological conditions promote stable associations of related individuals that benefit from jointly exploiting and defending common resources. High levels of cooperation and robust mechanisms of division of labour are found in many animal societies. However, conflicts among individuals are still frequent when group members that are not genetically identical compete over reproduction or resource allocation.Key Concepts:Eusociality is a form of highly integrated social organisation that is characterised by reproductive division of labour, cooperative brood care and overlap of generations.Eusociality confers a great ecological success, but has a scattered taxonomic distribution.Kin selection is the key process explaining the evolution of permanently nonreproductive helpers. However, in some taxa helpers delay reproduction until a breeding opportunity becomes available.Eusociality evolved in family groups under ecological conditions promoting the joint exploitation and defence of common resources.Eusociality is linked with division of labour, which is sometimes associated with morphological castes.The allocation of workers to tasks is a self‐organising process that occurs without central control and emerges from local interactions.In social insects, division of labour is remarkably robust and flexible to cope with unpredictable changes in the environment.Individuals in animal societies are not clones: they have partially divergent genetic interests, which can lead to various forms of conflicts.Some types of conflicts can be controlled by social means such as bribing, coercion or punishment.