MEMORIAL UNIVERSITY
Separate and distinct: Genetic analysis gives insight into island caribou population

A genetic study has given Memorial researchers new insight into the origin and evolution of the Island of Newfoundland's caribou population and has won recognition from Canada's leading genetics journal.

Their findings are available in a recently published paper based on Corinne Wilkerson's (M.Sc.'10) thesis and co-authored with Dr. Steve Carr, Department of Biology, Faculty of Science, and Shane Mahoney (B.Sc.(Hons.'77), M.Sc.'80), a conservationist/wildlife manager.

Genetic testing has shown Newfoundland caribou are distinct from mainland caribou.Their study was the first extensive genetic analysis of caribou in Newfoundland. It aimed to understand the genetic relationships of Newfoundland caribou among themselves and in relation to those on the mainland.

The first question the researchers were interested in was whether Newfoundland caribou could be considered a distinct subspecies.

"From the DNA sequence data, we were able to identify four genetic groups," said Ms. Wilkerson. "Three of them, which represented the majority of samples, are distinct from mainland caribou. That supported our hypothesis that Newfoundland caribou are indeed a separate subspecies, Rangifer tarandus terranovae."

Closely related

While distinct, they did prove to be most closely related to caribou in Labrador and Quebec, suggesting an answer to a second question: How did caribou repopulate the island after the last glaciation 10,000 years ago?

"We know the Grand Banks of Newfoundland were above water at the time, and the accepted theory was that they retreated to a refugium [an area in which a population can survive during a period of unfavourable conditions] there," said Dr. Carr. "This is known to be the case for other species. However, the pattern of diversity we found suggested the opposite."

The northwestern and central populations show a great deal of genetic variation, whereas the Avalon population shows almost none.

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