Graduate Research
The Issues
The fisher (Pekania pennanti) is a member of the weasel family that was trapped for its fur in the early part of the 20th century. As a result, fishers were eliminated from many parts of their historic range. In Ontario, Canada, fishers persisted in small, isolated populations in parks and game preserves and have since recolonized the province. Although fisher numbers have increased sufficiently that they are no longer considered rare, historic population size reduction and partitioning often results in low genetic diversity. This lack of genetic variation can reduce a species' ability to adapt to changing environments.. Since fishers are a top predator and are still trapped for fur, another reduction in their population numbers would have both ecosystem and economic impacts. I am interested in the conservation of these fascinating animals, and my graduate work focused on learning more about their recolonization. The Methods To do this, I used both traditional population genetics methods as well as functional genomics. I started by quantifying genetic diversity and differentiation of fishers in central and southeastern Ontario by looking at variation in neutral genetic markers. Genetic structure was last assessed ten years ago, and comparing these data with contemporary data provided information on the rate and direction of gene flow between populations, increasing our knowledge of how fishers are recolonizing Ontario. I am also assessed variation in specific genes related to traits important for fisher survival. The amount of variation in these functional genes has important implications for the species' potential to adapt if their habitat was to change. The Implications My project addressed questions relevant to the conservation of fishers and deepened our theoretical understanding of how species recover from small population size and fragmentation. |
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Undergraduate Research
My undergraduate honours thesis, which I completed at Queen's University under the supervision of Dr. Stephen Lougheed, looked at genetic differentiation between mainland and island populations of northern water snakes (Nerodia sipedon sipedon) and eastern garter snakes (Thamnophis sirtalis). The two species have overlapping ranges but differ markedly in habitat usage, body size, and tendency to disperse. I wanted to determine how these factors influenced gene flow by comparing the population genetic structure of the two species. One site of particular interest to this study was Main Duck Island, a small and isolated island in Lake Ontario.
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