Research Interests

The main goal of my research is to discover how complex biological interactions control the divergence of genes, individuals and populations.  During the early part of my career, I concentrated on how phenotypes such as migration or mating behavior affect population genetic structure, and how this population structure in turn affects the evolution of these phenotypes.  For example, the amount of genetic variation within and between groups determines the potential for group selection, while the outcome of selection at this level can determine population structure by shaping migration and dispersal rates.  Now that genomic and molecular genetic tools are becoming increasingly available for model evolutionary systems, I have expanded my research to include the molecular genetic level of analysis.  For example, we have discovered that opsin genes in the guppy have undergone recent duplication and diversification, in parallel with the diversification and duplication of the genes controlling male coloration.  This suggests that not only has sexual selection led to the diversification of these genes, but also that the physical duplication of these genes may have allowed for strong sexual selection to develop in this group of species.  In order to understand the interaction of genetic forces at multiple levels of biological organization, I have chosen to study tractable systems for which there is extensive background knowledge, such as the guppy, and systems with important applied outcomes, such as human immunoglobulin loci.