The Paleohistory of Circumpolar Arctic Colonization

acquire the means with which to confront the ecological and climatic con- ditions of the Arctic, although the characteristic conditions of this zone are not identical to those of the Pleistocene perigla- cial zone which extended to much more southerly latitudes. Unfortunately, it is difficult to follow the movements of human groups towards the north because of the several ad- vances by northern glaciers which have covered human traces in the northern regions of Eurasia and America with a thick layer of moraine and fluvioglacial deposits. This movement has to be reconstructed from isolated traces, particularly in those rare sectors of the far Eurasian north which were not covered by the ice sheet during the Wurm glaciation. These observations enable us to reconstruct the prehistoric cultures which spread into northern Eurasia and to relate them to the climatic pattern of the Upper Pleistocene. These cultures developed under the influence of the periglacial environment, sometimes in regions situated much further south. Stone tools, settlement structures, ways ,qf life, and arts and crafts which developed at this time belonged to cultural traditions that per- sisted for long periods and occupied zones which were some- times very extensive. The first adaptations to arctic environments date from the end of the Lower Paleolithic, during the penultimate glaciation (Riss/S&le + WartelDnieprovskoye + Moskovskoye), when the periglacial zone extended far to the south, covering the contemporary temperate zone. Unfortunately, we have no idea of the northern limit of human occupation at this period. The map of Acheulian settlements shows that in Europe and Asia this limit was not very far to the north, rarely approaching the Riss periglacial zone (Collins, 1969). It is more often the Clac-