Final answer:
The connection between Asia and America that allowed early human migration is most directly associated with the Bering Land Bridge Theory, which posits that people crossed from Siberia to Alaska on foot. Another theory, the Pacific Coastal Route, suggests a maritime path following the coast from Asia to the Americas.
Step-by-step explanation:
The dry land connection between Asia and America, which facilitated the entrance of people to the New World, is most commonly associated with the Bering Land Bridge Theory. This theory states that the earliest inhabitants of the Americas crossed a land bridge, known as Beringia, which connected northeast Siberia to what is now Alaska when sea levels were lower during the last ice age. This migration is estimated to have started around 15,000 years ago, with people following migratory herds over the marshy and exposed Beringia land bridge into the Americas.
Another widely-discussed proposal is the Pacific Coastal Route, which suggests a maritime path following the coastline from Asia across the Bering Land Bridge down to North and South America. This coastal migration theory is supported by archaeological evidence showcasing early settlements in South America that predate those of North America. However, fewer sites support this theory due to the coastline of the Pleistocene era now lying submerged under the Pacific Ocean due to rising sea levels.