Background. Balancing selection - the selective maintenance of fitness related genetic variation - can be caused by different mechanisms. While much of our work examines how environmental heterogeneity promotes balancing selection, we also investigate how behavioral mechanisms can generate and maintain functional variation.

Current project - the white throated sparrow. In collaboration with Elaina Tuttle at Indiana State University, Chris Balakrishnan at East Carolina University, and others, we are studying the evolutionary history of an large inversion polymorphism that remains at a stable frequency in the species via nearly obligate disassortative mating. We have recently shown (Tuttle et al. 2016) that this polymorphism arose via interspecific hybridization and appears to be evolving in a similar fashion as a neo-sex chromosome. We are continuing to examine the evolutionary history and functional properties of this super-gene through population- and quantitative-genetic techniques.