According to my research, Cervus elaphus migrated across the Bering land bridge during the late Pliocene Period, spreading across the continent.
As the climate and geography changed, individual populations developed distinct characteristics, yet were genetically similar.
Biologist Valerius Geist claims all American elk are C. canadensis canadensis, claiming that classification of the four surviving North American groups as subspecies is driven, at least partly, for political purposes to secure individualized conservation and protective measures for each of the surviving populations.
Recent DNA studies suggest that all American Elk seem to belong to one subspecies (Cervus canadensis canadensis). Even the Siberian elk (Cervus canadensis sibiricus) are more or less identical to the American forms and therefore may belong to this subspecies, too.
Due to subsistence and market hunting, virtually all elk were removed from the Cascade range due to winter migrations to lower elevations, and the subsequent ease of unrestricted/unregulated harvest.
Reintroduction returned elk to their former range, but due to being so genetically similar, cross breeding is possible, and within a few generations all differences are assimilated into the genetics of the native population.
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