Projects
My main research interest is how adaptation can drive the formation of new species. This process is potentially central to evolutionary biology because it unifies the main force in microevolution (natural selection) with the major pattern of macroevolution (the existence of species). Furthermore, it is a very plausible idea, because nearly all populations are exposed to novel environments, and the selection for local adaptation can be very strong.
My research on this topic addresses two questions. First, does adaptation create reproductive isolation between populations? This might involve assortative mating between populations in different environments, or a reduction in hybrid fitness because they fall between ecological niches. Second, does local adaptation promote the evolution of other isolating mechanisms by reducing the rate of gene flow at other genetic loci?
I am working on these questions with two study systems: the hybrid zone between the fire-bellied toads Bombina bombina and B. variegata in Romania, and the benthic and limnetic sticklebacks of British Columbia. This summer I started working on hybrid zones between stream and marine sticklebacks. These zones are an amazing opportunity to address the above questions, because they occur independently in many rivers and streams all around the Northern Hemisphere, and, unlike Bombina, we have a fully sequenced genome. This means we can examine how loci that are under selection in either enviroment contribute to reproductive isolation. See the Stickleback HZs project page for more details. Click on the links above or the left hand menu for more information on the individual experiments.