On April 2, 2007, A.Th.E.N.S. Presents

five mechanisms for the evolution of cooperation

by Professor Martin Nowak

Cooperation means that one individual pays a cost for another individual to receive a benefit. Cost and benefit are measured in terms of fitness. Reproduction can be genetic or cultural. I will discuss five mechanisms for the evolution of cooperation: kin selection, group selection, network reciprocity (=graph selection), direct reciprocity and indirect reciprocity. Each mechanism leads to a simple rule that specifies whether cooperation can be favored by natural selection. I will argue that cooperation is essential for constructing new levels of organization in biology. The emergent genomes, cells, multi-cellular organisms, and human society are all based on cooperation.