The Phylogeny of the Four Pan-American MtDNA Haplogroups: Implications for Evolutionary and Disease Studies

The Farming/Language Dispersal Hypothesis posits that prehistoric population expansions, precipitated by the innovation or early adoption of agriculture, played an important role in the uneven distribution of language families recorded across the world. In this case, the most widely spread language families today came to be distributed at the expense of those that have more restricted distributions. In the Americas, Uto-Aztecan is one such language family that may have been spread across Mesoamerica and the American Southwest by ancient farmers. We evaluated this hypothesis with a large-scale study of mitochondrial DNA (mtDNA) and Y-chromosomal DNA variation in indigenous populations from these regions. Partial correlation coefficients, determined with Mantel tests, show that Y-chromosome variation in indigenous populations from the American Southwest and Mesoamerica correlates significantly with linguistic distances (r = 0.33-0.384; P < 0.02), whereas mtDNA diversity correlates significantly with only geographic distance (r = 0.619; P = 0.002). The lack of correlation between mtDNA and Y-chromosome diversity is consistent with differing population histories of males and females in these regions. Although unlikely, if groups of Uto-Aztecan speakers were responsible for the northward spread of agriculture and their languages from Mesoamerica to the Southwest, this migration was possibly biased to males. However, a recent in situ population expansion within the American Southwest (2,105 years before present; 99.5% confidence interval = 1,273-3,773 YBP), one that probably followed the introduction and intensification of maize agriculture in the region, may have blurred ancient mtDNA patterns, which might otherwise have revealed a closer genetic relationship between females in the Southwest and Mesoamerica.mtDNA | Uto-Aztecan | Y chromsome | maize | migration

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“…This subhaplogroup is termed B2a (50), and the network depicting the relationships between the B2a lineages is particularly interesting (Fig. 1).…”

Section: Resultsmentioning

confidence: 99%

Evaluating the Farming/Language Dispersal Hypothesis with genetic variation exhibited by populations in the Southwest and Mesoamerica

Kemp

González‐Oliver

Malhi

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…The pan-American haplogroup A2 (Achilli et al, 2008) represented more than 97% of Wao lineages. In fact, only two A2 haplotypes were observed.…”

Section: Discussionmentioning

confidence: 99%

Genetic uniqueness of the Waorani tribe from the Ecuadorian Amazon

et al. 2012

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South America and especially the Amazon basin is known to be home to some of the most isolated human groups in the world. Here, we report on a study of mitochondrial DNA (mtDNA) in the Waorani from Ecuador, probably the most warlike human population known to date. Seeking to look in more depth at the characterization of the genetic diversity of this Native American tribe, molecular markers from the X and Y chromosomes were also analyzed. Only three different mtDNA haplotypes were detected among the Waorani sample. One of them, assigned to Native American haplogroup A2, accounted for more than 94% of the total diversity of the maternal gene pool. Our results for sex chromosome molecular markers failed to find close genetic kinship between individuals, further emphasizing the low genetic diversity of the mtDNA. Bearing in mind the results obtained for both the analysis of the mtDNA control region and complete mitochondrial genomes, we suggest the existence of a 'Waoranispecific' mtDNA lineage. According to current knowledge on the phylogeny of haplogroup A2, we propose that this lineage could be designated as subhaplogroup A2s. Its wide predominance among the Waorani people might have been conditioned by severe genetic drift episodes resulting from founding events, long-term isolation and a traditionally small population size most likely associated with the striking ethnography of this Amazonian community. In all, the Waorani constitute a fine example of how genetic imprint may mirror ethnopsychology and sociocultural features in human populations.

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“…Sin embargo, destaca que la región de mayor incidencia del país sea La Araucanía y en particular que las dos comunas con mayor incidencia del país -muy por sobre la media nacional-tengan alta tasa de población mapuche. Las etnias indígenas chilenas como los mapuche están genéticamente relacionados con otros pueblos amerindios con ancestros comunes que migraron desde Asia 18,19 . La incidencia de EK en nativos de islas del Pacífico como Hawaii y Nueva Zelandia es mayor que en población caucásica y relativamente similar a la observada en población asiática 20,21 .…”

Section: Discussionunclassified