The relationships between populations of a species, and between closely related species, have often been estimated through the analysis of mitochondrial DNA (mtDNA). This study will test a key assumption on which conclusions from past mitochondrial DNA based phylogenies have rested. The assumption is that the amount of mtDNA variation across an entire species is negligible. This assumption is critical to the reconstruction of phylogenies and the interpretation of evolutionary histories, especially those of primates. Contrary to this assumption, within the female philopatric macaques, significant mtDNA variation exists within the same species. Unlike macaques, leaf monkeys exhibit female dispersal. Additionally, there are species within each genus that have similar geographic distributions. Through mtDNA analysis of two such species in each genus, we propose to: (1) examine the effects of female dispersal on distributions of mtDNA diversity (geography held constant); (2) assess the effects of geographic distribution on mitochondrial genetic structure within each genus (female dispersal held constant); and (3) determine whether the 'macaque' model of mtDNA population structure can be broadly applied to other higher primates. Hence, a mtDNA analysis of selected macaque and leaf monkey species pairs provides a naturally controlled situation in which to examine the effects of female dispersal on population structure based on maternally inherited mtDNA. This study uniquely examines the relationship between social organization and the dynamics of mtDNA evolution in higher primates. The information obtained will be crucial to recognizing limitations of mtDNA analysis for inferring primate phylogenies and evolutionary histories.
