ABSTRACT
Cooperation is the third fundamental principle of evolution, beside mutation and selection. Mutation generates variation upon which selection acts. Cooperation leads to the integration of competing units and allows the formation of higher levels of organization. The emergence of the first cells, of eucaria, of multi-cellular organisms, of animal societies, and of humankind are the consequences of cooperation. Cooperation is the creative force of evolution, which allows the emergence of complexity and structure and ultimately human life. Cooperation is never fully stable, but waxes and wanes. Natural selection tends to oppose cooperation unless specific mechanisms for evolution of cooperation are operative in a population (Nowak 2006). Presently five such mechanisms are known: direct reciprocity, indirect reciprocity, spatial selection, group selection, and kin selection. This chapter will discuss theoretical and empirical evidence for each of those mechanisms (Rand and Nowak 2013).
