9506781 Staub One of the intriguing questions in evolutionary biology is how do new traits arise. In several species of the salamander genus Aneides, females express features that typically are expressed only in males. Dr. Staub's research goal is to examine the hormonal basis for the normal expression of these traits in females. She will use both a comparative and experimental approach to investigate the relationship between hormonal and morphological variation. In the proposed project, differences between species and between males and females in jaw muscle sensitivity to male sex hormones (androgens) will be examined. In addition, hormone levels will be analyzed to determine seasonal patterns of androgens and estrogens. Results will be analyzed in an evolutionary framework with the goal of understanding how hormonal variation can explain the profound shape variation expressed within this salamander group. The significance of the proposed project is that it will provide information on the role of androgens in the development of female traits, a role that has remained relatively unexplored. ***
