Genotype-by-environment interactions when the social environment contains genes

In this chapter we examine the consequences of GSEIs for the evolution of male sexual traits and, more generally, the operation of sexual selection. We start by developing a series of simple quantitative genetic models to illustrate the importance of GSEIs to the evolutionary process and how they differ from standard GEIs when the environment is abiotic and therefore does not contain genes. We then provide a brief overview of how to measure GSEIs, as well as a discussion of empirical studies that have quantified GSEIs in the context of sexual selection. We conclude by suggesting some fruitful avenues for future research that we hope will stimulate more studies to examine the importance of GSEIs in sexual selection.