I was able to demonstrate that high elevation populations of Lyaeides butterflies in the Sierra Nevada represent a homoploid hybrid species. This species possesses traits (high oviposition preference for an alpine endemic host plant coupled with a loss of egg adhesion) that allow it to persist in the extreme alpine environment and may have been important for its establishment as a hybrid species (Gompert et al. 2006b). At present, I am working as part of a collaborative group to determine the ubiquity of hybrid speciation in this group of butterflies and whether certain traits or genomic regions are fixed in multiple hybrid species of independent origin.

In addition to my empirical work on hybrid speciation, I will be investigating the utility of using linkage information to detect hybrid species.

Recent studies combining phylogenetics and community ecology have demonstrated that competition drives ecological divergence among species of the same guild. However, the effect of positive interactions on ecological niche evolution are less well known. Marianne Elias, Chris Jiggins, Keith Willmott and I demonstrated that mutualistic interactions, specifically increased advertisement of toxicity to predators due to Mullerian mimicry, drives ecological convergence of neotropical ithomiine butterflies that share the same mimicry pattern (Elias et al. 2008).

Currently, I am using simulation-based models to assess the effect of  heterogenous predation pressures (i.e. different predators occupying different habitats) on several aspects of community composition and structure, such as: the number of mimicry groups occurring in a given community, the distribution of mimicry groups among habitats, and the evolution of species’ ecological niches.

Patterns of genetic variation in natural populations can be used to make inferences about population processes, such as population demography. Such information is relevant for understanding the evolutionary history of populations and species, as well as for conserving biological diversity. In collaboration with Chris Nice, Jim Fordyce, Matt Forister, and Art Shapiro I have investigated patterns of genetic variation in natural populations of Lycaeides to: determine whether the endangered Karner blue butterfly (L. melissa samuelis) represents a distinct ESU (Gompert et al. 2006a), uncover when and how Lycaeides colonized North America as well as whether they diversified in North America following colonization (Gompert et al. 2008a), and assess the extent and cause(s) of mitochondrial introgression among North American Lycaeides lineages (Gompert et al. 2008b).

I was also involved in a conservation genetics project on Eurycea salamanders with Lauren Lucas, Chris Nice, and Jim Ott. Eurycea populations are associated with springs and spring-fed streams throughout the Texas hill country. We demonstrated that this populations are genetically differentiated and show little evidence of gene flow, suggesting that migration rarely occurs among geographically isolated springs (Lucas et al. 2009). This information is important as several Eurycea lineages are endangered and threats to their habitat, such as human water use and drought, are likely to increase.

Karner blue butterfly populations west of Lake Michigan are infected with the endoparasitic bacteria Wolabachia, while those east of Lake Michigan are uninfected (Gompert et al. 2008). Moreover, an association between Wolbachia infection and an adaptively introgressing mitochondrial haplotype suggests that the strain of Wolbachia infecting Karner blue populations may cause cytoplasmic incompatibility. Chris Nice and I are currently conducting an extensive survey of Wolbachia infection status of Karner blue butterflies in conjunction with simulation modeling to determine the potential effect of Wolbachia spread to uninfected populations on Karner blue butterfly population persistence. This is particularly relevant as translocations and reintroductions are included in the Karner blue butterfly recovery plan.