Haplogroup X: An ancient link between Europe/Western Asia and North America?

[Desiree]

mtDNA haplogroup X: An ancient link between Europe/Western Asia and North America?

Brown MD, Hosseini SH, Torroni A, Bandelt HJ, Allen JC, Schurr TG, Scozzari R, Cruciani F, Wallace DC.

Center for Molecular Medicine, Emory University School of Medicine, Atlanta, GA, USA. mdbrown@gmm.gen.emory.edu

On the basis of comprehensive RFLP analysis, it has been inferred that approximately 97% of Native American mtDNAs belong to one of four major founding mtDNA lineages, designated haplogroups "A"-"D." It has been proposed that a fifth mtDNA haplogroup (haplogroup X) represents a minor founding lineage in Native Americans. Unlike haplogroups A-D, haplogroup X is also found at low frequencies in modern European populations. To investigate the origins, diversity, and continental relationships of this haplogroup, we performed mtDNA high-resolution RFLP and complete control region (CR) sequence analysis on 22 putative Native American haplogroup X and 14 putative European haplogroup X mtDNAs. The results identified a consensus haplogroup X motif that characterizes our European and Native American samples. Among Native Americans, haplogroup X appears to be essentially restricted to northern Amerindian groups, including the Ojibwa, the Nuu-Chah-Nulth, the Sioux, and the Yakima, although we also observed this haplogroup in the Na-Dene-speaking Navajo. Median network analysis indicated that European and Native American haplogroup X mtDNAs, although distinct, nevertheless are distantly related to each other. Time estimates for the arrival of X in North America are 12,000-36,000 years ago, depending on the number of assumed founders, thus supporting the conclusion that the peoples harboring haplogroup X were among the original founders of Native American populations. To date, haplogroup X has not been unambiguously identified in Asia, raising the possibility that some Native American founders were of Caucasian ancestry.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Retrieve&dopt=Citation&list_uids=99057522

[Tom Hebert]

...Caucasian ancestry.  That's certainly a possibility, especially in light of Kennewick Man.  And what about the Lost Tribes?  Could they have ended up in America?