Demographic and evolutionary trajectories of the Guarani and Kaingang natives of Brazil.

A total of 278 individuals from two Brazilian Indian tribes (Guarani and Kaingang) living in five different localities had their mitochondrial DNA sequenced for the first hypervariable segment (HVS-I), and a fraction of them was also studied for seven biallelic Y-chromosome polymorphisms. Nineteen HVS-I lineages were detected, which showed distinct distributions in the two tribes. The G(ST) value obtained with the mtDNA data is about 5 times higher for the Guarani as compared to the Kaingang, suggesting a higher level of differentiation between the three Guarani partialities than between the two Kaingang villages. Non-Amerindian admixture varied with sex and in the Guarani was only observed through the paternal line. Using these data and those of other Tupian and Jêan tribes, it was possible to make inferences about past migratory movements and the genetic differentiation of these populations. Copyright 2006 Wiley-Liss, Inc.