Roughly 14000 years ago rough 1000 humans made it to the Americas across the Bering Land Bridge.
A Malthusianly-unstressed preindustrial human population with reasonable access to food (whether hunter-gatherer, herder, or settled agriculture) roughly doubles in a generation of 25 years or so.
If the incipient Amerindian population had remained unstressed, how many Amerindians would there be today?
What implications does this have for how we think about the human history of the Americas between ca. 12000 BC and 1492?