Gene-Culture Coevolution

This chapter examines the evidence that our cultural activities have influenced our biological evolution, by drawing on a cocktail of theoretical and empirical findings. It begins by relating findings from theoretical studies, which show through mathematical modeling that gene–culture coevolution is, at least in principle, highly plausible. Then the anthropological evidence for gene–culture coevolution is surveyed. Here, compelling and well-researched case studies provide incontrovertible evidence that gene–culture coevolution is a biological fact. Finally, some genetic data are presented—specifically, studies that have identified human genes subject to recent natural selection, including genes expressed in the brain. Many such genes (strictly, “alleles,” or gene variants) have increased extremely rapidly in frequency over a few thousand years, and this unusually swift spread, known as a “selective sweep,” is taken as a sign of their having being favored by natural selection. The relevance of such studies stems from the fact that the geneticists who carried them out have concluded that the sweeps are almost certainly a response to human cultural activities. Collectively, these three bodies of evidence make a compelling case that culture is not just a product, but also a codirector, of human evolution.