Beza Mahafaly Sifaka Population Genetics

I am currently assisting in microsatellite genotyping of the many of Propithecus verreauxi samples collected from the wild population at Bezá Mahafaly Special Reserve over the last three decades. This work will contribute to the growing knowledge of this population's demography and evolutionary history, social and reproductive organization, and fitness trends. This research is in collarboration with Dr. Brenda Bradley (CASHP, The George Washington University), Dr. Richard Lawler (James Madison University), Dr. Alison Richard (Yale), and David Frankel (CASHP, The George Washington University).

Papionin Evolutionary History


The evolutionary history of the Cercopithecine subtribe Papionina has puzzled anthropologists for some time due to the apparent discordance between the morphological and molecular affinities of these taxa along with likely rapid successive speciation events and potential hybridization. These phenomena make the group a great candidate for study using emerging "species tree" phylogenetic techniques. We recently compared the performance of more traditional phylogenetic approaches with several of these, including the multispecies coalescent and Bayesian concodance, in this group. This research is in collaboration with Dr. Michael Steiper (Hunter College, CUNY).

Sifaka Population Genetics


My current research is focused on the epigenetics and comparative genomics of primate aging and life history in captive chimpanzees (Pan troglodytes) and the wild sifaka lemur population at Bezá Mahafaly Special Reserve in southwest Madagascar. 



Cercopithecid Phylogenetics

Sifaka photo credit: Sibien Mahereza

Development of DNA Extraction & Amplification Methods in the Field

Transporting biological specimens internationally for genetic analyses has drawbacks, including limiting the ability of local researchers and students to work with the samples and often invovling a slew of beaurocratic red tape. To get around these issues, I worked to develop protocols taking advantage of new equipment and reagent technologies to extract and amplify DNA without access to shelter or electricity. I worked on this project with Dr. Brenda Bradley (CASHP, The George Washington University) and with help from Dr. Jeannin Ranaivonasy (University of Antananarivo), Dr. Joelisoa Ratsirarson (University of Antananarivo), Dr. Richard Lawler (James Madison University), Dr. Alison Richard (Yale), Lydia Greene (Duke University) and Dr. Rachel Jacobs (CASHP, The George Washington University).

Read coverage of this protocol on Mongabay or the miniPCR blog.


Get protocol.


Oral Microbiome


Sifaka Microbiomes

I am characterizing the oral microbiomes of wild folivorous sifaka lemurs. The gut microbiome is being heavily studied, but primate oral microbiomes haven't yet been studied much in a comparative context. This kind of research can clarify the role of the oral microbiota in health and disease, including contextualizing modern human oral microbiomes. I'm working on this project in collarboration with Dr. Brenda Bradley (CASHP, The George Washington University), Dr. Jeannin Ranaivonasy (University of Antananarivo), Dr. Joelisoa Ratsirarson (University of Antananarivo), Dr. Richard Lawler (James Madison University), and Dr. Alison Richard (Yale).

Sensory Genetics


Gorilla Taste Genetics

Taste receptors are G-protein coupled receptors encoded by genes demonstrating variation that can produce differences in taste perception. I am examining variation among primates at sites within these genes that are experimentally known to alter taste perception. Such variation, for example in gorillas, may reflect co-adaptation with sympatric plants. I'm collaborating on this project with Dr. Brenda Bradley (CASHP, The George Washington University), Dr. Carrie Veilleux (University of Texas, Austin), Dr. Gisella Caccone (Yale Institute for Biospheric Studies), and Dr. Kristin Saltonstall (Smithsonian Tropical Research Institute).

Sifaka photo credit: Sibien Mahereza

Genetics Field Methods

Genetics Field Methods

Read about this project on the Leakey Foundation blog.

Dissertation Research: Comparative Epigenetics of Human and Chimpanzee Aging

Humans are long-lived compared with other primates, including our closest extant relatives, chimpanzees (Pan troglodytes). However, little is known about the underlying physiological basis of human exceptional longevity. Recent research notably demonstrates that humans show a pattern of epigenetic change with age so predictable that is can be used to accurately estimated chronological age. I seek to characterize the patterns of epigenetic change with age in chimpanzees to explore the potential epigenetic component of differences in rate-of-aging in these two species.

Chimpanzee Epigenetic Age

Resequencing the Verreaux's sifaka genome

The Human Genome Sequencing Center at the Baylor College of Medecine, in collaboration with the Duke Lemur Center, recently undertook the de novo sequencing of the Coquerel's sifaka. A male Verreaux's sifaka from Bezà Mahafaly Special Reserve was sequenced as part of this larger endeavor. Since then, we have resequenced this genome using the Coquerel's sifaka assembly (species split: ~4-7Ma) as a reference and are currently performing genome scans for positive selection.

Sifaka Genome