The Stone laboratory is working on applications of population genetics to questions concerning the origins, population history and evolution of humans and the great apes. At present, our research focuses on the biological history of Native South Americans and on the evolution and genetic diversity of the genus Pan, which includes chimpanzees and bonobos. We are also working on projects that examine genetic susceptibility to tuberculosis in Native Americans, that investigate the evolutionary history of tuberculosis using ancient DNA, and that examine the exchange of tuberculosis and leprosy between humans and non-human primates..

Graduate Student Projects:

On the origins of leprosy: the primate connection. (Luz-Andrea Pfister)

The importance of non-human primates (NHPs) as sources of pathogens now adapted to humans has been highlighted by the HIV/AIDS epidemic. It is likely that NHPs, as our closest relatives, have shared pathogens with humans because the species “jump” for these pathogens is expected to require few changes. Several lines of evidence suggest that human leprosy may have a NHP origin, including the pervasive human and NHP sympatric coexistence in endemic regions of the Old World, where human leprosy seems to have originated as supported by archaeological, historical, and more recently genetic evidence. Further, this project follows preliminary work documenting the presence of the etiologic agent, Mycobacterium leprae, in 25% of tested NHP buccal swabs collected in South and South East Asia.

 The aim of this study is to test the hypotheses that human leprosy originated in NHPs using a single nucleotide polymorphism strain typing method in strains derived from both humans and NHPs. Specifically, we are collecting human and NHPs buccal swabs from Africa and Asia. Of these, we will sample 100 individuals (30 humans and 70 NHPs) who have tested positive for M. leprae for our study. Phylogenetic and population genetic analyses of the data obtained will enable the determination if human and NHP strains are being currently transmitted between species, the transmission direction, and ancestor/descent relationship.

This project is funded by the Wenner Gren Foundation for Anthropological Research.