Demography and H-Lea salivary secretion of the Macá Indians of Paraguay

New genetic data on Amerindians from the Paraguayan Chaco

New data on 17 blood group and protein genetic systems obtained among the Ayoreo and Lengua Indians of Paraguay are presented. They include the first report on the red cell band-3 protein investigated among South American Indians. This information was integrated with previous results available for these two and four other groups. Five of the six populations reside in the Chaco area, while the sixth was included as an outgroup living elsewhere in Paraguay. Four of the five Chaco tribes exhibit good genetic homogeneity, but the Ayoreo are somewhat different. The results confirm the Chaco as a distinct biological (as well as cultural and economic) region, which should be considered in evaluations of genetic variability among South American Indians.

Protein polymorphism in three South Amerindian populations

Electrophoretic polymorphism at loci coding for blood red cells and plasma proteins was analysed in three native populations of South America: Mataco and Macá (from the Gran Chaco), and Guayaki (from the Paraguayan forest). Mean heterozygosity per locus varied from 0.024 and 0.073, the Macá being the most polymorphic population, probably reflecting admixture with the caucasoid population of Asuncion city. Although the external phenotype, blood group frequencies and ethno-linguistic affiliation of the Guayaki clearly differ from those of the Chaco tribes, Nei's genetic distances were very low and almost equidistant among the three populations. Heterogeneity of F(ST) values among polymorphic loci would suggest the action of natural selection.

The Caingang revisited: blood genetics and anthropometry

A total of 248 individuals belonging to four populations of Caingang Indians from southern Brazil were studied in relation to 23 genetic systems that are expressed in blood and one manifested on saliva. These results were compared with those obtained in 400 members of these same communities that were subjected to 11 body measurements. Nine polymorphic loci (MNSs, P, Rh, Duffy, Diego, Hp, PGM1, ESD, and Gc) were chosen for the calculation of the genetic distances between the four populations, which were compared with Mahalanobis's D2 differences. The two sets of values proved to be intercorrelated but neither showed a relationship with the geographic distances separating the four communities. The Caingang were previously classified linguistically as Gê, and they show several affinities with the Gê tribes, both when hematological, and morphological, characteristics are considered. A variant PGD phenotype is also described, showing a curious storage effect.