Mitochondrial DNA Diversity in South America and the Genetic History of Andean Highlanders

Abstract

We analyzed mtDNA sequence variation in 590 individuals from 18 south Amerindian populations. The spatial pattern of mtDNA diversity in these populations fits well the model proposed on the basis of Y-chromosome data. We found evidence of a differential action of genetic drift and gene flow in western and eastern populations, which has led to genetic divergence in the latter but not in the former. Although it is not possible to identify a pattern of genetic variation common to all South America, when western and eastern populations are analyzed separately, the mtDNA diversity in both regions fits the isolation-by-distance model, suggesting independent evolutionary dynamics. Maximum-likelihood estimates of divergence times between central and south Amerindian populations fall between 13,000 and 19,000 years, which is consistent with a Pleistocenic peopling of South America. Moreover, comparison of among-population variability of mtDNA and Y-chromosome DNA seems to indicate that South America is the only continent where the levels of differentiation are similar for maternal and paternal lineages.

BetweenAndes andAmazon: The genetic profile of theArawak‐speakingYanesha

“…In particular, within the Y chromosome native haplogroup Q, the STR haplotypes show very high variance between populations within Amazonia, but greater homogeneity in the Andes, confirming a tendency previously reported (Luiselli et al, 2000;Tarazona-Santos et al, 2001;Fuselli et al, 2003;Barbieri et al, 2011;Bisso-Machado et al, 2012-see Table 2). The NJ tree for the Y chromosome R ST distances (Supporting Information Fig.…”

Global patterns of human mitochondrial DNA and Y-chromosome structure are not influenced by higher migration rates of females versus males

“…At present, there are too few studies that specifically examine these issues of scale with respect to Y-chromosome versus mtDNA differentiation to draw firm conclusions. But our results, taken together with several regional-scale studies that did not detect a genetic signal of increased migration among females versus males [20][21][22] , suggest that broader-scale genetic patterns may not always reflect the sum of local cultural processes. This may be because other demographic events (e.g., long-distance migrations) become proportionately more important at larger geographic scales, or because behavioral customs of individual populations do not have the temporal or geographic stability necessary to influence global patterning.…”

Divergent patterns of linkage disequilibrium and haplotype structure across global populations at the interleukin-13 (IL13) locus

“…We sequenced 3950 bp encompassing the promoter and coding region of IL13 in 132 individuals belonging to 11 worldwide populations from West Africa (14 Igbo, 14 Yoruba and seven Fulani from Nigeria collected by SAT), East Africa (17 Hadza, 10 Maasai from Tanzania collected by SAT), Europe (10 North Europeans and 10 Russians from the Coriell cell repository), Asia (10 Chinese from the Coriell cell repository) and South America (nine Cayapa from Ecuador, 17 Peruvian Quechua from Tayacaja and 13 from San Martin de Pangoa 51,56 ). All samples were collected with informed consent of the donors and the study was performed under Institutional Review Board approval.…”