Final answer:
The two main migration routes from Asia to America were through the Beringia land bridge and along the Pacific coast via the coastal migration theory.
Step-by-step explanation:
People crossing from Asia to America had two main migration routes, according to historical and archaeological evidence. These two routes include the interior route through Beringia, the land bridge that once connected Asia and North America, and the coastal migration theory that posits people followed the Pacific coastline in boats.
Beringia Land Bridge
The first inhabitants of the Americas are believed to have migrated across Beringia in search of food, later populating North and South America. With the melting of the glaciers, Beringia was submerged, creating the Bering Strait.
Coastal Migration Theory
The coastal migration theory suggests that some of the earliest migrants traveled by boat along the Pacific coast of Asia, continuing down the coast of North America to South America, supported by the diverse marine environment.