Beringia
Refugium

Analysis at Chukotka on the Siberian edge of the land bridge indicated that from c. 57,000 – c. 15,000 YBP (MIS 3 to MIS 2) the environment was wetter and colder than the steppe–tundra to the east and west, with warming in parts of Beringia from c. 15,000 YBP. These changes provided the most likely explanation for mammal migrations after c. 15,000 YBP, as the warming provided increased forage for browsers and mixed feeders. At the beginning of the Holocene, some mesic habitat -adapted species left the refugium and spread westward into what had become tundra-vegetated northern Asia and eastward into northern North America.
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