Sexual Selection Can Resolve Sex-Linked Sexual Antagonism

TLDR

Sexual selection is a powerful evolutionary force, yet few models examine how female preferences evolve for traits expressed in both sexes. This study investigates how female preferences coevolve with sexually antagonistic traits that benefit one sex while harming the other. The authors model the coevolution of female mate choice and sexually antagonistic alleles on sex chromosomes. They find that on the X chromosome females evolve preferences for alleles that benefit daughters, whereas on the Z chromosome preferences shift toward alleles that benefit sons, leading to flashy displays.

Abstract

Sexual selection is a potent evolutionary force. However, very few models have considered the evolution of female preferences for traits expressed in both sexes. Here we explore how female preferences coevolve with sexually antagonistic traits, which involve alleles that are beneficial to one sex but harmful to the other. We show that with a sexually antagonistic trait on the X chromosome (males XY, females XX), females evolve to prefer mates carrying alleles beneficial to daughters. In contrast, with a Z-linked trait (males ZZ, females ZW), females more often evolve mating preferences for mates carrying alleles beneficial to sons (that is, flashy displays).