ARTICLEmum (approximately 18.0 kya).3 Other Paleolithic sites in

Siberia lie far south of the Arctic Circle, implying that the early populations of extreme northeastern Siberia either became extinct or retreated to the south unless environ-mental conditions changed and permitted repeopling of the Siberian Arctic.4 The presence of Beringia would have important implications for resolving initial human settling of northwestern edge of the NewWorld.5–7 The last inhab-itants of former Beringia, the Yukaghir, Chukchi, Eskimo-Aleuts, and Na-Dene Indians, are likely the survivors of rapid environmental changes that took place in the late Pleistocene to early Holocene.8–10 Hence, these popula-tions deserve special attention focused on the issues, such as the number of NewWorld founders, where in Sibe-ria-Asia and Beringia progenitors of the First Americans arose, when and how they spread into the deglaciated hab