Answer:
what most archaeologists suspected about the location of this homeland. It also strongly suggested that the timing proposed in the Clovis First scenario was wrong. Geneticists now calculate, based on mutation rates in human DNA, that the ancestors of the Native Americans parted from their kin in their East Asian homeland sometime between 25,000 and 15,000 years ago—a difficult time for a great northern migration. Huge glaciers capped the mountain valleys of northeastern Asia, at the same time massive ice sheets mantled most of Canada, New England and several northern states.
The European presence in America spurred countless changes in the environment, negatively affecting native animals as well as people. The popularity of beaver-trimmed hats in Europe, coupled with Native Americans’ desire for European weapons, led to the overhunting of beavers in the Northeast. Soon, beavers were extinct in New England, New York, and other areas. With their loss came the loss of beaver ponds, which had served as habitats for fish as well as water sources for deer, moose, and other animals. Furthermore, Europeans introduced pigs, which they allowed to forage in forests and other wildlands. Pigs consumed the foods on which deer and other indigenous species depended, resulting in scarcity of the game native peoples had traditionally hunted.