The Awá-Guajá Indians of the Brazilian Amazon. Demographic data, serum protein markers and blood groups.

The South-American Indian group Awá-Guajá, currently living in the State of Maranhão (Northeastern Brazil), is one of the most recently contacted Indian groups of the Brazilian Amazon. This group is made up by three partially isolated villages named Awá, Guajá and Juriti, and is characterized by having a young population, in which 47.6% of the individuals range from 0 to 14 years old. The sex ratios (male/female) for people of reproductive age are 1.13 for Awá village, 2.00 for Guajá, 3.33 for Juriti and 1.61 for the tribe as a whole. Fst and heterogeneity analysis show that, despite the small differences observed among villages for the eight genetic systems analyzed, the Awá-Guajá tribe is constituted of only one population. Furthermore, comparisons between Awá-Guajá and Urubú-Kaapor tribes indicate that they are still isolated genetically, in spite of the fact that they share territories.