Evolutionary and Anthropological Implications of Mitochondrial DNA Variation in African Brazilian Populations

The genetic diversity in three African Brazilian populations was analyzed using the 360-nucleotide sequences of the first hypervariable segment (HVS-I) of the mitochondrial DNA control region. Results from 42 individuals revealed 39 distinct lineages defined by 54 variable positions. Some of the sequence types were clearly African derived, but apparent Amerindian lineages also occurred. The lineage clusters did not show any association with place of residence of the individuals or with their morphological classification. Nucleotide diversity, however, seemed to be associated with degree of admixture. The mismatch distribution suggests a major human population expansion 60,000 years ago.