Mitochondrial haplogroup M discovered in prehistoric North Americans

Mitochondrial haplogroup M discovered in prehistoric North Americans

Received 21 April 2006; received in revised form 8 July 2006; accepted 11 July 2006

We analyzed two mid-Holocene (w5000 years before present) individuals from North America that belong to mitochondrial DNA (mtDNA) haplogroup M, a common type found in East Asia, but one that has never before been reported in ancient or living indigenous populations in the Americas. This study provides evidence that the founding migrants of the Americas exhibited greater genetic diversity than previously recognized, prompting us to reconsider the widely accepted five-founder model that posits that the Americas were colonized by only five founding mtDNA lineages. Additional genetic studies of prehistoric remains in the Americas are likely to reveal important insights into the early population history of Native Americans. However, the usefulness of this information will be tempered by the ability of researchers to distinguish novel founding lineages from contamination and, as such, we recommend strategies to successfully accomplish this goal.

I’m surprised I’ve not heard more noise around this. Unfortunately I couldn’t spot any information in the paper on what known population this M clade this might be closest too.

In this study we demonstrate the existence of this undocumented genetic structure with the discovery of two individuals from China Lake, British Columbia (Fig. 1) that exhibit a mitochondrial DNA (mtDNA) haplogroup never before reported in any prehistoric or living indigenous population in the Americas. Both were found in the same burial, dated to 4950 +/- 170 14C years before present (ybp), and were believed to be related due to similar morphological characteristics (Cybulski personal communication). Both individuals belong to haplogroup M, which is widely distributed throughout Asia (Kivisild et al., 2002). These individuals account for two of three samples dating to approximately 5000 ybp studied from the Northern Plateau region in Northwestern North America that were compared to 3658 sequences from Native Americans widely distributed throughout the Americas. The third sample dating to 4975  40 14C ybp from Big Bar Lake, British Columbia (Fig. 1), exhibits a haplogroup A haplotype that is shared with contemporary indigenous individuals. The discovery of a new mitochondrial haplogroup in the Americas conflicts with the presumed five-founder model, which implies that all Native American mtDNA derives from only five lineages, the founding haplotypes of haplogroups A, B, C, D, and X (Eshleman et al., 2003). Our discovery demonstrates that a more genetically diverse group of migrants colonized the Americas than previously thought and supports the hypothesis that significant undocumented genetic diversity likely still remains in the Americas.

This now brings the founding American mt lineages to six; A, B, C, D, X and M.


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