Individuals and groups in evolution: Darwinian pluralism and the multilevel selection debate

We outline here an updated review of “kin selection VS group selection” long standing debate. Group selection is a highly contentious concept, scientifically and philosophically. In 2012, Dawkins’ attack against Wilson’s latest book about eusociality concentrated all the attention on group selection and its mutual exclusivity with respect to inclusive fitness theory. The opponents seem to be both wrong facing the general consensus in the field, which favours a pluralistic approach. Historically, despite some misunderstandings in current literature, such a perspective is clearly rooted in Darwin’s writings, that suggested a plurality of levels of selection and a general view that we propose to name “imperfect selfishness”. Today, the mathematically updated hypothesis of group selection has little to do with earlier versions of “group selection”. It does not imply ontologically unmanageable notions of “groups”. We propose here population structure as the main criterion of compatibility between kin selection and group selection. The latter is now evidently a pattern among others within a more general “multilevel selection” theory. Different explanations and patterns are not mutually exclusive. Such a Darwinian pluralism is not a piece of the past, but a path into the future. A challenge in philosophy of biology will be to outline the logical structure of this emerging pluralistic theory of evolution in such contentious debates.