Genomic findings and their implications for the evolutionary social sciences

Abstract

What past selection pressures have shaped human traits and their variation and covariation across individuals? These are key questions in the evolutionary social sciences. Recent advances in the field of human genomics have yielded a wealth of evidence that sheds light on these questions, yet the findings and their implications seem to be little known in the evolutionary social sciences. In this paper I aim to bring together these findings while explaining the conceptual and technical background that is often assumed knowledge for reading the primary reports. First, I outline the genomics methodologies that have enabled the relevant findings, such as genomewide association studies and DNA-based heritability estimation. I describe how these methodologies reveal the genetic architecture of traits, and then how this information in turn enables inferences about past selection. The findings show pervasive evidence that the genetic architecture of complex traits has been shaped by negative (purifying) selection, implying that the extant genetic variation in the traits has been maintained by mutation-selection-drift balance. On the other hand, there is no evidence that balancing selection has substantively shaped complex traits, and strong evidence that it has not. Finally, I discuss the implications of these findings for issues such as the dimensional structure of personality variation and the plausibility of psychological life history theory.