Sexual behavior, genes, and evolution in Xiphophorus.

A century of research into both behavior and genetics in Xiphophorus has yielded important insights into the genetic architecture underlying sexual behavior, particularly as concerns male courtship and mating strategies. Two Y-linked loci underlie much of the variation in male mating strategies, possibly reflecting selection for modularization. Courtship behavior elements, in contrast, are under polygenic control. Little is known about the genetics of female mating preferences, yet behavioral evidence suggests that female preference complexes typically do not map on to suites of male traits. Natural hybrid zones in Xiphophorus present an ideal system for studying the evolutionary genetics of male traits and female preferences using contemporary molecular techniques.