Genetic structure of Quechua-speakers of the Central Andes and geographic patterns of gene frequencies in South Amerindian populations

Abstract

A sample of 141 Quechua-speaking individuals of the population of Tayacaja, in the Peruvian Central Andes, was typed for the following 16 genetic systems: ABO, Rh, MNSs, P, Duffy, AcP1, EsD, GLOI, PGM1, AK, 6-PGD, Hp, Gc, Pi, C3, and Bf. The genetic structure of the population was analyzed in relation to the allele frequencies available for other South Amerindian populations, using a combination of multivariate and multivariable techniques. Spatial autocorrelation analysis was performed independently for 13 alleles to identify patterns of gene flow in South America as a whole and in more specific geographic regions. We found a longitudinal cline for the AcP1*a and EsD*1 alleles which we interpreted as the result of an ancient longitudinal expansion of a putative ancestral population of modern Amerindians. Monmonnier's algorithm, used to identify areas of sharp genetic discontinuity, suggested a clear east-west differentiation of native South American populations, which was confirmed by analysis of the distribution of genetic distances. We suggest that this pattern of genetic structures is the consequence of the independent peopling of western and eastern South America or to low levels of gene flow between these regions, related to different environmental and demographic histories.

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.…”

Population Genetic Structure of Traditional Populations in the Peruvian Central Andes and Implications for South American Population History

“…Rothhammer and Silva (1989) were the first to argue for a distinct Andean pattern of biological variation as ascertained via craniometric isoline maps; this interpretation was supported by follow-up studies of craniometric and classical marker data Silva 1990, 1992;Cavalli-Sforza et al 1994). Beginning in the early 2000s, 5 spatial analyses of molecular data revealed that Andean populations contain a pattern of high within-and low between-population genetic variation as compared to populations in the Amazon and Orinoco River Basins, which appear to harbor much higher levels of between-group variation (Luiselli et al 2000;Simoni et al, 2000; Tarazona-Santos et al, 2001;Fuselli et al, 2003).…”

“…Rothhammer and Silva (1989) were the first to argue for a distinct Andean pattern of biological variation as ascertained via craniometric isoline maps; this interpretation was supported by follow-up studies of craniometric and classical marker data Silva 1990, 1992;Cavalli-Sforza et al 1994). Beginning in the early 2000s, 5 spatial analyses of molecular data revealed that Andean populations contain a pattern of high within-and low between-population genetic variation as compared to populations in the Amazon and Orinoco River Basins, which appear to harbor much higher levels of between-group variation (Luiselli et al 2000;Simoni et al, 2000; Tarazona-Santos et al, 2001;Fuselli et al, 2003).Subsequently, a distinction between "west" (i.e., the Andean mountain range and surroundings regions) and "east" (i.e., Amazonian lowlands and surrounding regions) has prevailed in discussions of continental South American population genetic variation (e.g., Pucciarelli et al 2006; Lewis et al 2007a;Wang et al 2007; Lewis and Long 2008; Lewis 2009;Yang et al 2010). This dichotomized representation of South American population genetic variation has had, in turn, important implications for the reconstruction of the continent's early population history.…”

“…This dichotomized representation of South American population genetic variation has had, in turn, important implications for the reconstruction of the continent's early population history. Whereas some researchers view the contrasting patterns as the outcome of two distinct initial colonizing events (Luiselli et al 2000;Rodríguez-Delfín et al 2001), others posit that the two regions experienced differing population histories only after the initial entry into South America through the Panamanian isthmus (Tarazona- Santos et al 2001;Fuselli et al 2003;Rothhammer and Dillehay 2009;Yang et al 2010;Bodner et al 2012). …”

“…Until recently, only fourteen western Andean populations have been represented in the scholarly literature; these populations are spread over more than 4,000 km ranging from Ecuador, to Peru, northwest Argentina, and northern Chile. Many of the post-1990s molecular studies are based on repeated genotyping efforts of an even smaller set of population samples (e.g., Luiselli et al 2000;Simoni et al 2000;Tarazona-Santos et al 2001;Fuselli et al 2003;Battilana et al 2006;Scliar et al 2012;Roewer et al 2013). Second, most relevant studies are based on either mitochondrial DNA (mtDNA) or Y-chromosome polymorphisms, which, in isolation, contain limited information about amounts and patterns of diversity (cf., Lewis and Long 2008).…”