Meeting Abstract
Comparative endocrinologists have increasingly adopted evolutionary approaches not only to characterize the evolution of the endocrine system itself, but also to leverage it as a framework for exploring basic evolutionary principles. For example, by virtue of their massively pleiotropic effects on the expression of genes and phenotypes, sex steroids and their receptors are predicted to (1) structure the patterns of phenotypic variance and covariance that are available to natural selection, (2) alter the underlying genetic correlations that determine a population’s evolutionary response to selection, and (3) facilitate evolutionary transitions in fitness-related phenotypes via subtle regulatory shifts in underlying tissues and genes. We present experimental support for each of these predictions by focusing on the specific case of androgen-mediated gene expression and sexual dimorphism in growth and ornamentation of Anolis and Sceloporus lizards. A central theme to emerge from these studies is that the rapidly increasing availability of genomic and transcriptomic data from non-model organisms places evolutionary endocrinologist in an excellent position to address the hormonal regulation of the key evolutionary interface between genes and phenotypes.
