Mate Choice, Speciation, and Hybridization

This chapter reviews the ample literature on mate choice and speciation, as well as the more novel topic of mate choice and genetic exchange among species. It begins by discussing the widespread support for the intuitive predictions that mate choice should promote diversification among geographically isolated species, and that mate choice should evolve to minimize drastic loss of fitness through hybridization. The role of mate choice is more complicated when there is incomplete divergence between lineages; depending on their relationship to other traits under selection, mating preferences can act to accelerate speciation through reinforcement, but they can also act to increase gene flow between divergent lineages. Finally, the chapter addresses the relationship between individual mating decisions and hybridization between species.