|Professional Interests||Current Projects||Publications||Student Researchers|
My research addresses fundamental questions in evolutionary biology via the study of links among organismal form, function, behavior, survival, and reproductive success. More specifically, I try to answer three inter-related questions: (1) how do hormones link animals to their biotic and abiotic environments through the regulation of performance traits important to fitness? (2) how does sexual selection shape physiological traits? and (3) what is the ecological significance of locomotor performance and how does selection act on the physiological traits underlying it? These components of my research explore how morphology and physiology interact with, and are shaped by, the environment through selection on their functional integration. Most of my research is conducted on lizards, but I also work with stalk-eyed flies and spiders to generalize how natural and sexual selection drive the evolution of form and function.
Physiological determinants of performance. I am using experimental approaches to determine whether and how steroid hormones, training, and diet (and their interactions) affect muscle physiology and performance capacity in lizards. This involves experimental removal, replacement, and supplementation of hormones, along with different training regimes and diets with varied protein content.
How endocrine systems regulate social behavior. I am studying Caribbean Anolis lizards to test what components of endocrine regulation are responsible for species differences in social behavior and life history strategy. To do this I am measuring circulating levels of steroid hormones in wild lizards, in addition to comparing target tissue sensitivity to these hormones. The main question is, has similar endocrine function re-evolved independently to regulate behavior, or are there multiple endocrine routes to the same behavioral end?
Direct and indirect effects of sexual selection on performance. I study lizards in the wild to determine what mating advantage performance capacity may give to better performers. (direct effects). I study stalk-eyed flies to test how a sexually selected ornament results in the evolution of traits that offset performance costs of the ornament (indirect effects).