In commemoration of Thomas Jefferson's 266th birthday, and as a follow-up to my post of March 15th, let me note that the Sage of Monticello was one of the earliest English-speaking Americans to speculate that American Indians originated in Siberia and migrated to North America via the Bering Strait. "From whence came those aboriginal inhabitants of America?" Jefferson asked in Query XI of Notes on the State of Virginia, his only book. "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 strait...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." (Merrill Peterson, ed., The Portable Thomas Jefferson [New York: Penguin, 1977], 142.)
Jefferson was not, however, the first European to hypothesize a Siberian origin for Native Americans. The concepts of a Bering land bridge and a Siberian migration to the Americas had been germinating for two centuries before Jefferson published them in his book. In Historia Natural y Moral de las Indias (1589), the Jesuit Jose de Acosta argued that since European animals were present in the Americas, they must have crossed over using a land bridge (which human beings could also have used). In the early 1600s the Spanish engineer Enrico Martin concluded that if such a land bridge existed, it must be in far northeastern Asia and the emigrants who used it must be Siberian. Around 1650, Bernabe Cobo asserted that the physical similarities between the various Indian peoples in North America pointed to a common origin, while in 1674 Daniel Gookin of Massachusetts noted that the most believable theory about the origins of Native Americans was that they were descended from the "Scythian" peoples of northeastern Asia and crossed into America via a land bridge. (Thanks to Charles Martijn, Daniel Mandell and John Faragher for the above information.)
Thomas Jefferson was a man of many talents: writer, inventor, lawyer, diplomat, scientist, naturalist, university founder, and, of course, president of the United States. Originality, however, wasn't necessarily his strongest suit.