USA HISTORY

Detailed explanation-1: -The settlement of the Americas began when Paleolithic hunter-gatherers entered North America from the North Asian Mammoth steppe via the Beringia land bridge, which had formed between northeastern Siberia and western Alaska due to the lowering of sea level during the Last Glacial Maximum (26, 000 to 19, 000 years ago).

Detailed explanation-2: -The Bering Land Bridge formed during the glacial periods of the last 2.5 million years. Every time an ice age began, a large proportion of the world’s water got locked up in massive continental ice sheets. This draw-down of the world’s liquid water supply caused major drops in sea level: up to 328’ (100 m) or more.

Detailed explanation-3: -This map shows how a land bridge connected the continents of Asia and North America when the most recent ice age lowered sea levels.

Detailed explanation-4: -As of 2008, genetic findings suggest that a single population of modern humans migrated from southern Siberia toward the land mass known as the Bering Land Bridge as early as 30, 000 years ago, and crossed over to the Americas by 16, 500 years ago.

Detailed explanation-5: -At 18, 000 years ago, Beringia was a relatively cold and dry place, with little tree cover. But it was still speckled with rivers and streams. Bond’s map shows that it likely had a number of large lakes. “Grasslands, shrubs and tundra-like conditions would have prevailed in many places, ” Bond said.