Current research efforts in my laboratory focus on examining the genetics of natural populations and on application of modern molecular genetic techniques to questions in evolutionary biology. I am particularly concerned with understanding the dynamics of DNA sequence divergence (within and among populations and species) and with using population genetic and phylogenetic methods to gain insights into population structure, evolutionary relationships and the origin of species. I am interested both in how DNA and protein sequences change over time and in using these changes as markers for understanding pattern and process in evolution.

Much of the research in the Harrison lab is directed toward understanding the origin of species, the evolution of barriers to gene exchange, and the history and current dynamics of natural hybrid zones. The lab currently focuses on two model systems: (1) a well-characterized mosaic hybrid zone between two species of field crickets and (2) two "strains" of European Corn Borer (ECB) which differ in pheromone communication system. In the crickets, we are examining patterns of infection with the bacterium Wolbachia, sperm competition, and sperm viability in an attempt to explain reproductive incompatibilities between the two species. We are also pursuing DNA-based approaches for identifying genes encoding reproductive proteins, with the aim of discovering molecules that mediate sperm competition and serve as oviposition stimuli. In ECB, we are constructing a linkage map that will serve as the framework for mapping major genes that control pheromone production and response and life history variation. An ultimate goal is to identify the genes responsible for phenotypic differences that appear to contribute to reproductive isolation between the two ECB strains

Many students in my lab develop their own research projects, and therefore the lab is host to a diverse array of studies in systematics, biogeography and population genetics. In addition to students working on the projects outlined above, I currently have students working on (1) population structure of whales; (2) systematics and patterns of diversification in gall-forming flies; (3) phylogeography and patterns of diversification in butterflies; (4) phylogeography and population structure in bark beetles.