查看文章

Patterns of genetic variation of a species can be shaped by events that occur at wide temporal and geographic scales. Geophysical processes, such as continental glaciations, can affect species vicariance at wide scales whereas processes that act at finer scales, such as gene flow between populations, can have more localized effects. Recent studies have shown that contemporary population structure should be interpreted within the context of historical events, such as ice-age vicariance, due to the hierarchical nature of genetic variation found in many species. The thinhorn sheep (Ovis dalli) is a mountain specialist found in northwestern North America, from the Brooks Range in Alaska, east through Yukon to the Mackenzie Mountains of Northwest Territories and south to the Rocky and Coastal Mountains of British Columbia. In this study, we examined the population genetic structure of thinhorn sheep in …