Origin: A Genetic History of the Americas

North America when Europeans first arrived. It must have taken an
extremely long time for the many thousands of “Indian” languages to have
developed, Jefferson argued, and they most plausibly came from northeast
Asia. He even suggested a possible route for their origination:
Again, the late discoveries of Captain Cook, coasting from
Kamschatka to California, have proved that, if the two continents of
Asia and America be separated at all, it is only by a narrow streight.
So that from this side also, inhabitants may have passed into
America: and the resemblance between the Indians of America and
the eastern inhabitants of Asia, would induce us to conjecture, that
the former are the descendants of the latter, or the latter of the
former: excepting indeed the Eskimaux, who, from the same
circumstance of resemblance and from identity of language, must be
derived from the Groenlanders, and these probably from some of the
northern parts of the old continent (12).
Despite Jefferson’s impressive accumulation of evidence, it would be a
century before this idea was accepted by the scientific community. By the
18th century, the Mound Builder hypothesis had become firmly entrenched
in public opinion as the leading explanation of North American prehistory
(13). Scholars and antiquarians continued to debate the identity of the
Mound Builders into the 19th century, with the majority agreeing that they
were not the ancestors of Native Americans. President Andrew Jackson
explicitly cited this hypothesis as partial justification for the Indian
Removal Act of 1830, barely 40 years after Jefferson published his book.
In the monuments and fortresses of an unknown people, spread over
the extensive regions of the west, we behold the memorials of a once
powerful race, which was exterminated, or has disappeared, to make
room for the existing savage tribes (14).
Thus did the idea of Manifest Destiny become inexorably linked with
concepts of racial categories. When someone asks me why I get so incensed
about the concepts of “lost civilizations” and “Mound Builders” that are