The Structure of Diversity within New World Mitochondrial DNA Haplogroups: Implications for the Prehistory of North America

Abstract

The mitochondrial DNA haplogroups and hypervariable segment I (HVSI) sequences of 1,612 and 395 Native North Americans, respectively, were analyzed to identify major prehistoric population events in North America. Gene maps and spatial autocorrelation analyses suggest that populations with high frequencies of haplogroups A, B, and X experienced prehistoric population expansions in the North, Southwest, and Great Lakes region, respectively. Haplotype networks showing high levels of reticulation and high frequencies of nodal haplotypes support these results. The haplotype networks suggest the existence of additional founding lineages within haplogroups B and C; however, because of the hypervariability exhibited by the HVSI data set, similar haplotypes exhibited in Asia and America could be due to convergence rather than common ancestry. The hypervariability and reticulation preclude the use of estimates of genetic diversity within haplogroups to argue for the number of migrations to the Americas.

Gene flow across linguistic boundaries in Native North American populations

“…Haplogroups A and D are concentrated in the far North and Northwest Coast, whereas haplogroups B and C appear regularly on the Northwest Coast and further South. Recent surveys of Native North American mtDNA confirm the haplogroup distributions observed for the populations and regions represented here; however, broader distributions for the A, B, C, and D haplogroups are noted when samples from other regions are included (32,33).…”

Identification of Native American Founder mtDNAs Through the Analysis of Complete mtDNA Sequences: Some Caveats

“…Indeed, in the case of the analyses of haplogroup C mtDNAs, one would have made a case for at least two distinct mtDNA founders if the control region sequence data were disregarded. On the other hand, it is clear that HVS-I data alone cannot provide sufficient evidence for founder status in view of a number of highly mutable sites, as emphasized by Malhi et al (2002), although their suggestion that the entire region of HVS-I might be hypervariable has not been substantiated in our studies. With the complete mtDNA sequence information currently at hand, we fail to see solid evidence for more than four founder mtDNAs entering Beringia before the LGM (one each from A, B, C, and D), with the additional possibility of one from haplogroup X (Brown et al 1998).…”

Antropología de la obesidad y de la diabetes gestacional

“…Hace veinte mil años, en el último período glacial, el nivel del mar bajó muchos metros, producién-dose un puente de tierra en la zona del actual estrecho de Bering, entre Asia y Alaska, llamado "Beringia". Vea el texto para comprender el impacto que esta migración tuvo en la resistencia insulínica de los aborí-genes de América (3,4).…”

“…Como consecuencia, la línea costera de todos los continentes se amplió significativamente (Figura 3). En el caso del tricontinente americano, el mar del estrecho de Bering (entre Alaska y Asia) fue sustituido por un puente de tierra firme, que se mantuvo por unos cinco mil años, al que se le ha dado el nombre de "Beringia" (3,4). Durante ese período, se produjeron varias oleadas migratorias desde Asia nororiental hacia las Américas, vía Beringia.…”