Our main model system is a small fish called the threespine stickleback (Gasterosteus aculeatus) and its close relatives in the stickleback family (Gasterosteidae). These fish have adapted to a variety of marine and freshwater habitats across the Northern hemisphere and consequently evolved incredible diversity in their behaviors, morphologies, life histories, and sex chromosomes on a relatively short evolutionary time scale. The development of genetic and genomic tools for these fish has allowed us to identify specific genetic, genomic, and molecular changes that underlie this phenotypic diversity and that contribute to reproductive isolation between phenotypically and ecologically divergent populations.
Currently, we are using this system (and others) to investigate the genetic and genomic basis of adaptation, particularly in cases of repeated adaptation to similar environments. We are also interested in the role of chromosomal rearrangements in both facilitating rapid adaptation to divergent environments and the evolution of sex chromosomes.
