Group Selection and Reciprocity among Kin

摘要

The question how Darwinian mechanisms lead to the evolution of individually costly cooperative behavior hasgiven rise to a number of hypotheses. However, attempts to build a synthesis where different types of mechanisms coexistand interact at different levels of selections are still scarce. Here we derive simple game theoretical models where thegroup level conflicts are resolved by group selection while simultaneously within group competition is resolved by kinselection and reciprocity. We show that none of the mechanisms, when alone, is as robust in evolving and maintainingcooperation as a synthesis of all. Furthermore, we show that initially within group conflicts can be overcome only by kinselection and not reciprocity. However, once common, different types of reciprocities can maintain high levels ofcooperation even if average relatedness among individuals is lowered, groups become large, and the benefits ofcooperation are reduced. Based on the synthesis we also propose a possible route to the evolution of social and eusocialsystems.