The evolution of Arctic marine mammals.

This review deals only with the evolutionary history of core Arctic marine mammals: polar bear (Ursus maritimus), walrus (Odobenus rosmarus), bearded seal (Erignathus barbatus), harp seal (Pagophilus groenlandica), ringed seal (Phoca hispida), bowhead whale (Balaena mysticetus), white whale (Delphinapterus leucas), and narwhal (Monodon monoceras). Sections on the evolutionary background of pinnipeds and whales help to provide a better perspective on these core species. Polar bears stemmed from brown bears about the Early to Middle Pleistocene. Fossils are rare; the earliest records are from approximately Early Weichselian deposits of Kew Bridge, London, and Svalbard. Existing Pacific and Atlantic walruses probably arose from splitting of a former Holarctic range during a Pleistocene glacial phase of extensive sea ice in the Canadian Arctic. The earliest known bearded seal remains are from Early to Middle Pleistocene deposits of Norfolk, England, and Cape Deceit, Alaska. Other Pleistocene fossils of this species are recorded from the North Sea, southwestern Sweden, and the Champlain Sea that existed in eastern North America approximately 12 000-10000 BP. The harp seal is the commonest pinniped in the Weichselian deposits of the southern North Sea. The earliest recorded fossil is from about 2 million years ago (2 Ma), from Ocean Point, Alaska. The earliest known Pleistocene ringed seal fossils are from last interglacial deposits near Teshekpuk Lake, Alaska, and Thule, Greenland, although an earlier (3 Ma?) specimen from Malaspina, Alaska, has been reported. This species seems to have been relatively abundant along the coasts of Prince of Wales Island, Alaska, during the Last Glacial Maximum. The bowhead whale probably originated in the high latitudes of the Northern Hemisphere. The earliest (mid-Wisconsinan) Canadian remains are from Ellesmere and Devon islands. More than 400 radiocarbon-dated bowhead remains have been used to reconstruct Holocene sea ice history in the Canadian Arctic. White whales are common in the late warming stage (approximately 10 500 BP) of the Champlain Sea and are one of the commonest marine mammal fossils in Late Pleistocene North Sea deposits. Fourteen narwhal specimens of Late Glacial or Early Holocene age are known from Atlantic Canada, as well as Ellesmere, Baffin, and Prince of Wales islands in Arctic Canada. Arctic marine mammals have tended to shift to more southerly ranges during glacial phases of the Pleistocene.

New dates on northern yukon artifacts: holocene not upper pleistocene.

New radiocarbon dates on four artifacts that were thought to provide evidence for human occupation of the Yukon Territory during the upper Pleistocene indicate that all four are of late Holocene age. The original radiocarbon age obtained for one artifact (the so-called "Old Crow flesher") was in error by almost 26,000 years.

Upper Pleistocene Radiocarbon-Dated Artefacts from the Northern Yukon: Man was in Beringia 27,000 years ago.

The evidence presented here indicates that man lived in the eastern part of the Beringian refugium before the peak of the late Wisconsin glaciation (27). He had sharp, stone tools intended for working bone and means of breaking large mammoth bones. Probably he hunted mammoth and caribou, and prepared the skins of the caribou for use as clothing and perhaps shelter. It is possible that he migrated to southern North America, although evidence for the presence of man there prior to the peak of the Wisconsin glaciation is at present in dispute (28). We do not know whether his culture should be classified as Mousteroid or Aurignacoid in Müller-Beck's scheme (23), whose criteria are taken from stone implements of which we have none, although we infer their presence. Our data suggest that in Beringia, and therefore probably in Siberia and the Far East, the transition from Middle Paleolithic to Upper Paleolithic levels of technology occurred at a relatively early date. This raises the larger question: Did the transition from Middle to Upper Paleolithic occur simultaneously in many parts of the world, or did it begin in and spread from one area (23)?

Lupinus arcticus Wats. Grown from Seeds of Pleistocene Age.

Seeds of the arctic tundra lupine (Lupinus arcticus) at least 10,000 years old were found in lemming burrows deeply buried in permanently frozen silt of Pleistocene age in unglaciated central Yukon. They readily germinated in the laboratory and have since grown into normal, healthy plants.