Modern Native American DNA

Between 1993 and 1996, mitochondrial DNA analyses of Native Americans established the presence of five major mtDNA types A, B, C, D (Torroni et al. 1993a, 1993b) and X (Bandelt et al. 1995; Forster et al. 1996) in the Americas. While types A–D are found across the Americas, X has a regional distribution, being restricted to North America, where it is found approximately along the latitude of the Great Lakes, that is, along the perimeter of the former Laurentide ice sheet. Asians also have these mtDNA types, with A, C and D being widespread and frequent, whereas B is absent in northern Asia, and X is rare or absent throughout Asia.

What is rarely pointed out in this early research, but striking in retrospect, is the very low rate of admixture from European or African females: indeed subjects who report Native American ancestry in their maternal line are almost certain (over 99%) to have one of these five Native American mtDNA types. On the paternal side, as measured by the Y chromosome typing, the story is very different. There are three Native American Y chromosome types, the major type Q, and the rarer types C and O. All of these are found in northern Asia. In addition, and in contrast to the mtDNA picture, there is extensive evidence of European admixture in the male lineages; even in Greenland Eskimos the European Y-chromosomal proportion is found to be as high as 50%. Conversely, in “white” Latin Americans, European Y chromosomes dominate, while Latin American mtDNA is largely or predominantly Native American, along with some African admixture.