The Origin of Diversity in Mammals of the Canadian Arctic Tundra

• Published in: Systematic Zoology
• Main Author: MacPherson, A. H.
• Format: Text
• Language: English
• Published: Oxford University Press 1965
• Subjects: Articles; Arctic; Arctic Fox; Sea ice; Tundra; Beringia
• Online Access: http://sysbio.oxfordjournals.org/cgi/content/short/14/3/153; https://doi.org/10.2307/2411546

The 17 modern Canadian arctic tundra mammals share only six broad patterns of taxonomic variation and geographic distribution. These are believed to result from differing distributions during the Wisconsin glacial stage, and the past distributions to have been in large part determined by the ecological relations of the species during the preceding interglacial stage. Those that were tundra species were able to maintain populations in the northern refugia, both in Beringia and Pearyland if the species was widespread (e.g., varying lemming) and only in the former if confined to western North America (e.g., brown lemming). Tree-line species (e.g., caribou) gave rise to both woodland and tundra forms, the former from populations isolated south of the ice, and the latter from populations trapped in the cooling northern refugia. Other species maintained themselves only in Beringia (e.g., man), and others only south of the ice-sheets (e.g., wolverine). Two species, polar bear and arctic fox, find sea-ice no barrier to distribution, and their present ranges are of as little zoogeographical relevance as those of anadromous fish.