Genetic isolation of wolverine (Gulo gulo) populations at the eastern periphery of their North American distribution

Abstract

Conservation strategies have a tendency to discount range peripheries, but recent evidence suggests that range edges may be important to species persistence by harboring genetic variants not found in core distributions. Wolverines in Canada are recognized as existing in two populations-an endangered eastern population and an extant western population thought to be largely panmictic. Studies from western North America identified strong patterns of female philopatry and increased genetic structure at the current southwestern periphery. Due to the paucity of data from the contemporary eastern periphery, it remains unclear if similar patterns exist at this range edge. Using neutral microsatellite and mitochondrial DNA markers from a broad geographic extent (>2,500 km), we found that wolverines at the eastern periphery displayed strong patterns of genetic distinctiveness from northwestern populations. While the microsatellite data suggest contemporary genetic structure exists, the haplotypic composition of the eastern periphery drastically differed from the core, indicating longstanding differences between regions. Further research is needed to determine if wolverines from the eastern periphery show evidence of interactions with the functionally extirpated eastern population, if functional markers display similar patterns of genetic diversity, and what relevance these may have in their evolutionary potential. Pronounced environmental fluctuations at range boundaries likely contribute to peripheral populations having genotypes with a greater capacity to respond to future selection pressures like climate change and may become a vital source of genetic diversity should core regions become replaced by edge habitats, and thus warrant separate conservation consideration. © 2012 Springer Science+Business Media B.V.