Abstract

Both ecological and sexual selection can contribute to population divergence and speciation. Recent theory and data suggest that interactions between these two selective pressures may be particularly powerful in generating species diversity. For example, sensory adaptation may change mating preferences through pleiotropy; and mate choice for locally adapted partners can accelerate divergent adaptation.

In my talk, I will present some of my research on East-African cichlid fish and Panamanian poison frogs. These case studies show how natural and sexual selection together can shape diversity in animal signals and promote reproductive isolation. They also illustrate, however, the difficulties of distinguishing alternative evolutionary scenarios, and of determining their relative importance and temporal sequence.