What role does adaptation play in population differentiation and speciation in highly mobile organisms?

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Traditionally, new species were thought to originate following gradual genetic divergence of populations separated by a physical barrier to dispersal. However there are many large gaps in our understanding of speciation. For example, do the same factors disrupt dispersal in different species? Do highly mobile species adapt to local conditions genetically? My research team is addressing questions such as these in seabirds. Seabirds present useful study systems because their ecology is generally well understood, and they are easy to sample in large numbers. Furthermore, because they encounter few physical barriers to dispersal, non-physical factors that can promote divergence in a variety of organisms are more evident than in less mobile organisms. In the previous funding cycle, we found several surprising challenges to the traditional model of speciation. In the present application, I propose to investigate the role of local adaptation in population differentiation and speciation in highly mobile organisms. Specifically, I propose to apply a combination of ecological (e.g. life history) data and cutting-edge genomic methods to investigate A) the genetic basis of parallel adaptation in seasonal races of band-rumped storm-petrels, and B) the extent of local adaptation in two species of arctic seabirds. Two approaches are planned: 1) genome-wide comparisons of individuals differing in a key trait (e.g. breeding season); and 2) investigation of functional variation in target (candidate) genes such as 'clock' (involved in the timing of reproduction and migration) and 'ADCYAP1' (potentially involved in migratory restlessness). Given our extensive DNA archive, network of collaborators and history of innovation, my lab is uniquely positioned to maximize the findings from these study systems. The proposed work will clarify the genetic basis of functional traits, fitness effects of these traits, and levels of variation in functional genes. Results are important for understanding both the potential for, and rate of, local adaptation, and have direct conservation benefits for several species of Canadian seabirds. This program will provide multidisciplinary training for 4 Ph.D., 3 M.Sc. and approx. 10 B.Sc. students.