Mate choice for indirect genetic benefits: scrutiny of the current paradigm

Abstract

Summary Sexual selection through mate choice, and in particular female choice for indirect fitness benefits for their offspring, is a major paradigm that currently seems to enjoy almost unequivocal acceptance. A large body of theoretical work has been built to explain the evolution of mate choice in the absence of direct benefits, and the empiricists have enthusiastically verified the various assumptions and predictions of the theory. However, the relative importance of mate choice for indirect benefits in comparison to choice for direct benefits or to other mechanisms of sexual selection such as male–male competition or sensory exploitation remains a controversial issue, and this seems to be forgotten in many empirical studies. Here we discuss what mate choice is, and how mating bias resulting from mate choice can be distinguished from mating biases resulting from other mechanisms such as male–male competition or sensory exploitation. We will argue that the evidence for active mate choice for indirect benefits is not as compelling as the current paradigm suggests, and that the current emphasis on active mate choice for indirect benefits has resulted in a distorted view of the nature of sexual selection. We emphasize that unlike the other mechanisms, active mate choice must come with a cost to females. We conclude by suggesting what we feel are three important areas that require further study before active mate choice for indirect fitness benefits should be concluded.