Final answer:
Early humans reached the Americas by crossing over Beringia, a land bridge between Siberia and Alaska.
Step-by-step explanation:
Many scientists believe that early humans reached the Americas by crossing on foot over Beringia, a land bridge between Siberia and Alaska that existed during the last Ice Age. This migration is known as the Bering Land Bridge Theory, and it is supported by archaeological evidence such as artifacts and DNA studies.
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