Some scientists think that Native Americans migrated from?

Answer 1

It is either Europe Aisa or Spain.

Edit:

Decades ago, it was believed and taught in schools that the aboriginal tribes came over the frozen Bering Strait between Russia and the United States. Later in the twentieth century, some scientists believed there was a coastal sea route from South America through North America which lead to the belief the Indians might be decendants of southern peoples. Still others have surmised that Indian tribes came over from Mongolia and Africa. Late in the twentieth century, pottery shards were found in the southwest United States that have been carbon dated to be 25,000 years old. Since the Ice age is about 18,000 year old only, it negates the Bering Strait theory.

In truth, no one really knows from where they emigrated or IF they emigrated. Most tribes have stories where their Peoples have been on this continent since memory. Meaning they have always been here.

Answer 2

The first settlers to America were believed to have migrated from Siberia and Alaska having crossed the ice bridge. Other settlers came by boat as time went on.