THE PHYLOGENETIC DISTRIBUTION OF A FEMALE PREFERENCE

Robust phylogenetic information can be instrumental to the study of th e evolution of female mating preferences and preferred male traits. In this paper, the evolution of a preexisting female bias favoring a swo rd in male swordtail fish and the evolution of the sword, a complex ch aracter, are used to demonstrate how the evolution of mating preferenc es and preferred traits can be examined in a phylogenetic context. Phy logenetic information suggests that a preference for a sword arose pri or to the evolution of the sword in the genus Xiphophorus and that the sword was adaptive at its origin. A phylogenetic approach to the stud y of female preferences and male traits can also be informative when u sed in conjunction with mate choice theory in making predictions about evolutionary changes in an initial bias, both prior to the appearance of the male trait it favors and subsequent to the appearance of the t rait.