title: Mitochondrial population genomics supports a single pre-Clovis origin with a coastal route for the peopling of the Americas.
abstract: It is well accepted that the Americas were the last continents reached by modern humans, most likely through Beringia. However, the precise time and mode of the colonization of the New World remain hotly disputed issues. Native American populations exhibit almost exclusively five mitochondrial DNA (mtDNA) haplogroups (A-D and X). Haplogroups A-D are also frequent in Asia, suggesting a northeastern Asian origin of these lineages. However, the differential pattern of distribution and frequency of haplogroup X led some to suggest that it may represent an independent migration to the Americas. Here we show, by using 86 complete mitochondrial genomes, that all Native American haplogroups, including haplogroup X, were part of a single founding population, thereby refuting multiple-migration models. A detailed demographic history of the mtDNA sequences estimated with a Bayesian coalescent method indicates a complex model for the peopling of the Americas, in which the initial differentiation from Asian populations ended with a moderate bottleneck in Beringia during the last glacial maximum (LGM), around approximately 23,000 to approximately 19,000 years ago. Toward the end of the LGM, a strong population expansion started approximately 18,000 and finished approximately 15,000 years ago. These results support a pre-Clovis occupation of the New World, suggesting a rapid settlement of the continent along a Pacific coastal route.
authors.affiliation: Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, 91619-900, Brazil.
authors.forename: Nelson J R
authors.initials: NJ
authors.lastname: Fagundes
authors.forename: Ricardo
authors.initials: R
authors.lastname: Kanitz
authors.forename: Roberta
authors.initials: R
authors.lastname: Eckert
authors.forename: Ana C S
authors.initials: AC
authors.lastname: Valls
authors.forename: Mauricio R
authors.initials: MR
authors.lastname: Bogo
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Salzano
authors.forename: David Glenn
authors.initials: DG
authors.lastname: Smith
authors.forename: Wilson A
authors.initials: WA
authors.lastname: Silva
authors.forename: Marco A
authors.initials: MA
authors.lastname: Zago
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Ribeiro-dos-Santos
authors.forename: Sidney E B
authors.initials: SE
authors.lastname: Santos
authors.forename: Maria Luiza
authors.initials: ML
authors.lastname: Petzl-Erler
authors.forename: Sandro L
authors.initials: SL
authors.lastname: Bonatto
mesh_terms: D044467:American Indian or Alaska Native / Q000235:genetics*; D000569:Americas; D004272:DNA, Mitochondrial / Q000235:genetics*; D004641:Emigration and Immigration; D023281:Genomics; D006239:Haplotypes; D006801:Humans; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial