However heretical Gladwin’s suggestions may be, they deserve serious attention if only because they bear heavily upon an old quarrel of the archaeologists, and because this old quarrel bears upon the antiquity of man in the Americas. To be sure, it has to do with the Indians who made the civilizations of Middle America and Peru two thousand years ago, and not with the earlier men who did no more than hunt or gather, and who made nothing more remarkable than Folsom and Eden points or milling stones. But by studying certain aspects of those civilizations we may recognize that the Indians had been in the Americas 3,000 to 5,000 years before Columbus. By so much we may reenforce the theory that their forerunners or their forebears came to the New World at least 15,000 years ago and probably 25,000 or more years ago.
Since 1950, Joseph Birdsell and Carleton Coon have done something to clear a little of the mist that has obscured the physical origins of man in the New World. They agree, more or less, that the first migrants were of Caucasoid stock from the basin of the Amur River, in northeast Siberia.[32]
Birdsell, a close student of the Australian aborigines, finds three strains in these peoples, one of which is traceable to the “white” Ainus, of northern Japan, and finally to what he calls the Amurians of the aforementioned river basin. In Australia their descendants are rather short and stocky, with a “rough-hewn Caucasoid cast of features.” Their craniums are long and low, with large brow ridges—general traits of Pleistocene man as well as some of our possibly early, and certainly problematical, Americans. Coon supposes that natural selection among the Amurians—trapped by the advance of the fourth glaciation or one of its substages—produced certain Mongoloid features that they later carried into the New World. Birdsell sees among the early migrants no Negritos, no full-sized Negroids, no so-called Melanesians, no Mediterranean type of Caucasoids. He suggests that a much-mixed strain of Caucasoid Amurians and the newly evolved Mongoloid race accounts for earliest man in the Americas. These “present the only discernible elements available at the proper time and place to have contributed importantly to the New World populations.... One may speculate that if human populations reached the New World in the third interglacial they could be expected to be purely Caucasoid, that is Amurian, and to show no Mongoloid characteristics.” Birdsell suggests that migrants coming after the last glaciation would carry some Mongoloid features through hybridization. Guardedly, Birdsell insists that, though this is a satisfying and stimulating hypothesis, we have as yet no means of judging accurately racial affiliations from a single cranium or entire populations. He concludes—somewhat sadly, we surmise—that methods utilized as recently as 1949 (the date of his proposal) offer no promise of unraveling in detail the enigma of the origins of our earliest Americans.