A quantitative genetic model of group selection

The dynamics of a finite number of phenotypic characters in a subdivided population, evolving by the combined effects of individual and group selection, is modeled using a quantitative genetic theory. This model of group selection allows prediction of per-generation evolutionary responses of metapopulation mean phenotypes. These predictions are based on measurements of the selection gradient in each group, the additive genetic variance-covariance matrix within groups, the group selection gradient, and the intergroup variance-covariance matrix. The equilibrium intergroup variance-covariance matrix is presented for a migrant pool model and individual selection within groups. Numerical calculations demonstrate that group selection can significantly influence the metapopulation mean phenotypes with a realistic amount of intergroup divergence of phenotypes through drift and migration.