was the ice age during the paleolithic era
Paleolithic The Paleolithic is often held to finish at the end of the ice age (the end of the Pleistocene epoch), and Earth's climate became warmer. This may have caused or contributed to the extinction of the Pleistocene megafauna, although it is also possible that the late Pleistocene extinctions were (at least in part) caused by other factors such as disease and overhunting by humans.[17][18] New research suggests that the extinction of the woolly mammoth may have been caused by the combined effect of climatic change and human hunting.[18] Scientists suggest that climate change during the end of the Pleistocene caused the mammoths' habitat to shrink in size, resulting in a drop in population. The small populations were then hunted out by Paleolithic humans.[18] The global warming that occurred during the end of the Pleistocene and the beginning of the Holocene may have made it easier for humans to reach mammoth habitats that were previously frozen and inaccessible.[18] Small populations of wooly mammoths survived on isolated Arctic islands, Saint Paul Island and Wrangel Island, until c. 3700 BCE and c. 1700 BCE respectively. The Wrangel Island population became extinct around the same time the island was settled by prehistoric humans.[19] There is no evidence of prehistoric human presence on Saint Paul island (though early human settlements dating as far back as 6500 BCE were found on the nearby Aleutian Islands).[20]
Settlement of the Americas The onset of the Last Glacial Maximum after 30,000 years BP saw the expansion of alpine glaciers and continental ice sheets that blocked migration routes out of Beringia. By 21,000 years BP, and possibly thousands of years earlier, the Cordilleran and Laurentide ice sheets coalesced east of the Rocky Mountains, closing off a potential migration route into the center of North America.[8][9][10] Alpine glaciers in the coastal ranges and the Alaskan Peninsula isolated the interior of Beringia from the Pacific coast. Coastal alpine glaciers and lobes of Cordilleran ice coalesced into piedmont glaciers that covered large stretches of the coastline as far south as Vancouver Island and formed an ice lobe across the Straits of Juan de Fuca by 15,000 14C years BP (18,000 cal years BP).[11][12] Coastal alpine glaciers started to retreat around 19,000 cal years BP [13] while Cordilleran ice continued advancing in the Puget lowlands up to 14,000 14C years BP (16,800 cal years BP)[12] Even during the maximum extent of coastal ice, unglaciated refugia persisted on present-day islands, that supported terrestrial and marine mammals.[10] As deglaciation occurred, refugia expanded until the coast became ice-free by 15,000 cal years BP.[10] The retreat of glaciers on the Alaskan Peninsula provided access from Beringia to the Pacific coast by around 17,000 cal years BP.[14] The ice barrier between interior Alaska and the Pacific coast broke up starting around 13,500 14C years (16,200 cal years) BP.[11] The ice-free corridor to the interior of North America opened between 13,000 and 12,000 cal years BP.[8][9][10] Glaciation in eastern Siberia during the LGM was limited to alpine and valley glaciers in mountain ranges and did not block access between Siberia and Beringia.[7]