The Role of Sexual Selection in the Loss of a Sexually Selected Male Trait

Ohio University, Athens OH

Investigators

Abstract

The role of sexual selection in the loss of a sexually selected male trait Molly R. Morris The role of sexual selection (female mating preferences and male-male competition for mates) in producing exaggerated or conspicuous male traits has been well documented, and yet recent comparisons of closely related species have suggested that loss of these male traits may be more common than gains. This project examines the roles of both male-male competition and female choice in the loss of the pigment pattern "vertical bars" found across several species of Xiphophorus fishes. By comparing the responses of males and female to the bars in closely related species it will be possible to determine when the bars were lost in relation to the loss of female preference and male response. The reliability of comparative studies ultimately depends on the reliability of the information about the relationships among the species. Therefore, this project will resolve the relationships within this group of fishes by comparing extensive DNA sequence data for all 22 species of this model system of fishes. This project will provide training for one postdoctoral fellow, two graduate students and one undergraduate student at Ohio University, as well as invitations to students at the Instituto de Biologia in Mexico City to go on field trips.