Autosomal STR Genetic Variability in the Gran Chaco Native Population: Homogeneity or Heterogeneity?

SG CROSSETTI, DA. DEMARCHI, PE RAIMANN, FM SALZANO, MH HUTZ, SM CALLEGARI-JACQUES

AMERICAN JOURNAL OF HUMAN BIOLOGY

Wiley-Liss

Lugar: New York; Año: 2008 vol. 20 p. 704 - 711

1042-0533

In order to investigate the population structure and variation in Gran Chaco´s Amerindian population, data from 15 short tandem repeats (STRs) were determined in 128 individuals from three tribes of the Argentinean part of this region . STR genotypic differences, structure analysis, and multidimensional plot for the DA distances indicated that  (1) Wichí from the Chaco Province are genetically distinct from the other populations, butstill preserve a fair amount of genetic similarity with Wichí from Formosa; (2) the Tobapopulations studied are genetically indistinguishable; and (3) Toba subjects from Formosa are similar to the Pilagá of the same linguistic group (Guaykurú) and to the Wichí from Formosa who speak a Mataco language. This similarity could be due to their past mobility and the custom of absorbing females taken as prisoners from groups raided by them. Language, geography and genetics seem to play similar roles in determining the population structure of these groups. Analyses of Molecular Variance and GST? values calculated considering three South American regions indicated that the Argentinean Chaco is genetically homogeneous; addition of the Ayoreo Amerindians of the Paraguayan Chaco, however, led to diversity values which are not much different from those of South Amerindians in general. The present data contribute to efforts that try to understand in what way groups with diverse sociocultural settings (tribal, agricultural, industrial) differ in genetic structure.