Hybridization and population genetics of two macaque species in Sulawesi, Indonesia

This study investigates hybridization and population genetics of two specie s of macaque monkey in Sulawesi, Indonesia, using molecular markers from mi tochondrial, autosomal, and Y-chromosome DNA. Hybridization is the interbre eding of individuals from different parental taxa that are distinguishable by one or more heritable characteristics. Because hybridization can affect population structure of the parental taxa, it is an important consideration for conservation management. On the Indonesian island of Sulawesi an explo sive diversification of macaques has occurred: seven of 19 species in the g enus Macaca live on this island. The contact zone of the subjects of this s tudy, M. maura and M. tonkeana, is located at the base of the southwestern peninsula of Sulawesi. Land conversion in Sulawesi is occurring at an alarm ing pace; currently two species of Sulawesi macaque, one of which is M. mau ra, are classified as endangered species. Results of this study indicate th at hybridization among M. maura and M. tonkeana has led to different distri butions of molecular variation in mitochondrial DNA and nuclear DNA in the contact zone; mitochondrial DNA shows a sharp transition from M. maura to M . tonkeana haplotypes, but nuclear DNA from the parental taxa is homogenize d in a narrow hybrid zone. Similarly, within M. maura divergent mitochondri al DNA haplotypes are geographically structured but population subdivision in the nuclear genome is low or absent. In M. tonkeana, mitochondrial DNA h aplotypes are geographically structured and a high level of nuclear DNA pop ulation subdivision is present in this species. These results are largely c onsistent with a macaque behavioral paradigm of female philopatry and oblig ate mate dispersal, suggest that introgression between M. maura and M. tonk eana is restricted to the hybrid zone. and delineate one conservation manag ement unit in M. maura and at least two in M. tonkeana.