Mitochondrial DNA variation in Eritrean hamadryas baboons (Papio hamadryashamadryas): life history influences population genetic structure

The hamadryas baboon, Papio hamadryas hamadryas, represents a rare exceptio n from the pattern of female philopatry and male-biased dispersal predomina nt in mammals including primates. To elucidate the possible consequences of the dispersal pattern on the population genetic structure of hamadryas bab oons, we sequenced the maternally transmitted mitochondrial hypervariable r egion I of 74 individuals from ten sampling locations in different ecogeogr aphic zones of Eritrea. To this end, individual fecal samples were collecte d at sleeping cliffs. Upon comparing the individual sequences by means of p hylogenetic tree reconstructions and AMOVA, we could not detect a populatio n genetic structure corresponding to a geographic pattern. Tree reconstruct ions revealed the existence of two profoundly different lineages both prese nt at most of the sampling locations. These findings and Mantel correlation s of genetic distances and the frequency of shared haplotypes to geographic distances point to the presence of female dispersal. Female-mediated gene flow is detectable over geographic distances exceeding those between neighb oring subpopulations. Our study therefore corroborates local behavioral obs ervations on a broad geographic scale. After inclusion of geographically cl osely situated olive baboons, P. h. anubis, in the analyses, all anubis seq uences fell within one hamadryas clade. Possible scenarios leading to this situation including long-term hybridization processes are discussed.