Intraspecific phylogeographic mitochondrial DNA (D-loop) variation of Gelada baboon, Theropithecus gelada, in Ethiopia

The genetic variations among four populations of gelada baboon, Theropithecus gelada, from the southern and northern highlands of the Rift Valley in Ethiopia were analysed, using restriction fragment length polymorphism (RFLP) of mitochondrial DNA (D-loop). Two haplotypes localized geographically with sequence divergence of 9.8% (±2.3% S.E.) distinguished the southern and northern allopatric populations, showing a historical break in the geographic distribution of the species and an impediment to gene flow. No variations were detected within or between the local populations. This marked divergence is concordant with recent nuclear DNA study. The most conspicuous barrier to gene flow is the Rift Valley, formed more than 2.5 million years ago. Considering the significant nuclear, mitochondrial, morphological, and behavioral differences, we believe that the newly found gelada population is a distinct subspecies.