Abstract
Native Americans derive from a small number of Asian founders who likely arrived to the Americas via Beringia. However, additional details about the intial colonization of the Americas remain unclear. To investigate the pioneering phase in the Americas we analyzed a total of 623 complete mtDNAs from the Americas and Asia, including 20 new complete mtDNAs from the Americas and seven from Asia. This sequence data was used to direct high-resolution genotyping from 20 American and 26 Asian populations. Here we describe more genetic diversity within the founder population than was previously reported. The newly resolved phylogenetic structure suggests that ancestors of Native Americans paused when they reached Beringia, during which time New World founder lineages differentiated from their Asian sister-clades. This pause in movement was followed by a swift migration southward that distributed the founder types all the way to South America. The data also suggest more recent bi-directional gene flow between Siberia and the North American Arctic.
Highlights
The mitochondrial DNA haplogroup nomenclature that is widely used today in population and medical genetics, forensic science, and in other interdisciplinary studies, traces back to the analysis of Native American populations by Torroni et al [1],[2]
Genetic studies demonstrate that Native Americans inherited their mitochondrial DNA from a handful of founders who arrived from Asia via Beringia [1],[2]
In this study we identified three sub-clades - C1b, C1c and C1d - that incorporate most of Native American haplogroup C mitochondrial DNA (mtDNA)
Summary
The mitochondrial DNA haplogroup nomenclature that is widely used today in population and medical genetics, forensic science, and in other interdisciplinary studies, traces back to the analysis of Native American populations by Torroni et al [1],[2]. The first four letters of the phylogenetic alphabet for mtDNA haplogroups A-D - were coined to refer to just four founding haplogroups that exhibit virtually all North and South American mtDNA diversity. No more than four major pan American and three minor North American founding mtDNA haplotypes (A2, B2, C1, D1 and X2a, D2, D3, respectively) have been convincingly established in previous studies of control region sequence, RFLP markers and 30 complete mtDNA genomes (Table 1) [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. Previous estimates of mtDNA diversity are predominantly based on control region sequences representing only a minor fraction of the mtDNA genome. Control region sequences experience a high frequency of recurrent mutations, potentially obscuring the identification of additional founding mtDNAs [14,15,16,17,18,19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
