Endemic Chromosome Races of the Common Shrew Sorex araneus L. (Insectivora, Mammalia) and the Possible Preservation of Refugia in the Late Valdai Glaciation Area

摘要

The hypothesis on the Valdai ice sheet has repeatedly raised doubts because of flora endemism in the glaciation area of northwestern Europe [1] and because of strangely rapid forest recovery during the postglacial period in spite of the slow natural dispersal of woody species [2]. In terms of the traditional geomorphologic notion of the ice sheet, the preservation of forest refugia in the glaciated area, as well as forest growth from the pioneer species near the glacier edge [3], conflicts with the biological potential of the woody species and with regular successions of the vegetation cover. At the same time, the ice sheet hypothesis clarifies the question of the appearance of some forms of relief, including moraine, kame, zvontsy, and sandr ones.