The overall goal of my research is to develop a mechanistic understanding by which coevolutionary species interactions drive the direction and rate of evolutionary change. I use a combination of mathematical modeling and molecular analysis in both field and laboratory settings to address how species interactions influence life history trait evolution, such as dispersal and virulence. My ongoing research broadly fits into the topics below.
Intimate host-symbiont associations are ubiquitous in natural communities and require mechanisms that insure that symbionts are transmitted from one host to another each generation. The goal of my research is to develop evolutionary genetic theory for understanding how coevolution between hosts and their symbionts affects co-transmission of host and symbiont genomes.
In populations at an adaptive equilibrium with their local environment, selection should favor philopatry over dispersal to different environments. But, theory shows that spatial environmental variation alone selects against dispersal. Yet, the vast majority of species exhibit some level of dispersal, mediated by behavior or morphology. Parasites are a particularly puzzling example. Many parasites are highly mobile, use different hosts within a life cycle, and have broad host ranges. The goal of my research is to develop population genetic models to provide an understanding of mechanisms by which abiotic and biotic interactions generate selection on dispersal.
Populations evolve in response to changes in abiotic environments, like climate, as well as to changes in genetic environments, like the internal genetic environment of other genes (epistasis) or the social milieu of parents and other members of the population. In all cases, the rate of adaptation depends upon the frequency of the selective environment. The goal of my research is to develop general theory to directly compare how species evolve in response to abiotic and genetic environments.