Genetic diversity among African great apes based on mitochondrial DNA sequences

The mitochondrial DNA D-Loop region was sequenced, analyzed and used as a molecular marker for populations of chimpanzee (Pan troglodytes), bonobo (P. paniscus) and gorilla (Gorilla gorilla and G. beringei), and also compared with data previously reported for these taxa. In Gorilla, a main disjunction between western (G. gorilla) and eastern (G. beringei, including G. b. graueri) species was observed, as well as high mitochondrial diversity within the western species. The genetic distance values within G. gorilla (0.14) were higher than those between subspecies (eastern lowland and mountain 0.12). Likewise, values of genetic diversity within this species (0.05) were higher than those between species (western and eastern lowland gorilla 0.04). Similarly, in genus Pan a main differentiation between western (P. t. verus) and central forms (P. t. troglodytes and P. t. schweinfurthii) was observed. The obtained values of genetic distance and genetic diversity revealed that the central subspecies are closer to each other than either of them is to the western one, while bonobos composed a distinct clade that expresses a well-defined specific identity. The current distribution, phylogeny and levels of genetic diversity in African great ape populations are consistent with the hypothesis that Pleistocene climatic events led to cyclical periods of isolation in forest refugia followed by expansion and dispersal. The implications of this high level of genetic diversity for taxonomic classification, wildlife management and conservation are discussed.