Environmental History Of The Arctic

Modern Arctic ecosystems began to take shape about two to three million years ago, as Earth's climate began to cool significantly. Most Arctic regions, including eastern and Central Canada, Greenland, Scandinavia, and western Russia, were buried repeatedly by glacial ice during the 17 or more glacial periods of the last two million years (the Quaternary Period). Presumably biological communities invaded the regions of the Arctic that became ice-free during the warmer interglacial periods, but we have little fossil evidence of these communities, because subsequent advances of glacial ice scoured these Arctic landscapes, obliterating the fossil evidence that accumulated during interglacial periods. The only Arctic regions not affected by glacial ice during the Quaternary were the lowlands of the Yukon Territory of Canada, Alaska, and eastern Siberia. These unglaciated regions, plus the continental shelves of the Bering and Chukchi seas between Siberia and Alaska, are known as Beringia. Since the fossil record of Beringia was not wiped out by glacial ice, paleontologists have been able to reconstruct the history of the Arctic flora and fauna of this vast region. Accordingly, most of this article focuses on this region, where Arctic biota found refuge during the ice ages.

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