[HamiltonJay]

New evidence can always change what we know, however we do know this, tribes tend to grow to about 30 members, when they get above this size, new tribes branch off and form, and move away to set up new encampments not very far from the original territory in agregarian societies.

Nomads follow food, not exploration, moving with the animals they hunt migrating over distances through the seasons.

At this point there is no evidence that humans conquered the americas in weeks or decads. Could it have happened that way? Sure, but right now there isn't.

I think you may have misread something, the land bridge was believe crossed during last ice age about 10-15k years ago, if I am not mistaken, and once in the americas took about another 1000 years to spread throughout the land, that would mean that people were in the amazon 9000-14000 years ago... which is more than enough time to have millions of inhabitants in a tropical rain forest basin where food is plentiful and temperature is moderate.

[RightWhale]

I think you may have misread something

Always. However, I do not believe the Bering land bridge was the primary means of access to America. Why trudge through endless miles of muskeg when you can paddle along at a much faster pace with a lot more provisions in a boat. If the aborigines, relatives of those in Australia, arrived 50,000 years ago, they would leave little sign of an archaeological nature. There is not enough data for more than a tentative timeline, although we are finally starting to dig in America and letting somebody else dig in Egypt, Babylon, and elsewhere, and should be ready for some assumption-exploding discoveries.