Gene-culture association and coevolution

The genetic evolution of cultural species can be altered by the dynamic interaction of their genes with their cultural traits. In humans, examples of gene-culture interactions are common and a deeper theoretical understanding of gene-culture coevolution is a necessary precursor to recognizing the effects of culture on human evolution. Although there are a large number of empirical studies of gene-culture coevolutionary phenomena and a large amount of verbal theory, our theoretical understanding of gene-culture co-evolution, of what kinds of cultural traits are relevant, and of the quantitative nature of cultural interactions with genes remains incomplete. Two models of gene-culture coevolution in which there are interactions between cultural transmission biases, viability selection, and genetic evolution are presented. We show that gene-culture coevolution can occur in the absence of selection on the cultural trait, that some parameters can lead to internal equilibria in which all genetic and cultural types are polymorphic, that gene-culture association may be maintained, and that gene-culture coevolutionary systems have rich and unexpected dynamics.