How were efforts to determine the pre-Columbian population of America tied to the larger debate over the consequences of European settlement of the Western Hemisphere?

The early migrants firstly settled in America and came across Bering Straight.

Due to these diverse population, they scattered.

And the Natives developed by hunting, gathering, fishing. and started farming, and stayed at one place.

But before the appearance of the Columbian population, North America were having around 16 million Indians.

And

Thereafter, the population of Indians reduces due to the loss of battles against the spread of the White civilizations.