Is there a Unifying Concept of Sexual Selection that Applies to Both Plants and Animals?

This article introduces a symposium on sexual selection in plants and animals and seeks a definition of sexual selection that applies to both kingdoms. Ten different criteria that could be used as a basis for defining sexual selection are reviewed. In particular, I argue that "mate choice" and "sexual competition" are problematic elements that should be avoided in a definition. In place of these elements, I argue for a mating success definition of sexual selection and propose that it constitutes a unifying concept that applies to both plants and animals.