Quantifying the phenome-wide response to sex-specific selection in Drosophila melanogaster.

Abstract

In species with separate sexes, selection on males causes evolutionary change in female traits values (and vice versa) via genetic correlations, which has far-reaching consequences for adaptation. Here, we utilise a sex-specific form of Robertson's Secondary Theorem of Natural Selection to estimate the expected response to selection for 474 organismal-level traits and ~28,000 gene expression traits measured in the Drosophila Genetic Reference Panel (DGRP). Across organismal-level traits, selection acting on males produced a larger predicted evolutionary response than did selection acting on females, even for female traits; while for transcriptome traits selection on each sex produced a roughly equal average evolutionary response. For most traits, selection on males and females was predicted to move average trait values in the same direction, though for some traits, selection on one sex increased trait values while selection on the other sex decreased them, implying intralocus sexual conflict. Our results provide support for the hypothesis that males experience stronger selection than females, potentially accelerating adaptation in females. Furthermore, sex-opposite responses to selection appear to exist for only a small proportion of traits, consistent with observations that the inter-sex genetic correlation for fitness is positive but less than one in most populations so far studied.