RESEARCH

Overview

 

My current research is focused on the epigenetic, genomic, and molecular physiological correlates of primate aging and life history, with a particular focus on lemurs and apes. I am also interested in sensory and dietary ecology, as well as conservation genetics of the wild sifaka lemur population at Bezá Mahafaly Special Reserve in southwest Madagascar. 

Genetics Field Methods

Lemur

Physiological

Aging

Physiological mechanisms of lemur life history trade-offs

Lemurs show striking variation in life history. Life history theory posits that senescence results from from imperfect somatic maintenance owing to trade-offs between the physiologically costly processes that organisms must sustain. In this project, we are looking at variation in aging biomarkers across lemur species to assess whether molecular aging profiles correspond to evolve life history patterns. This project is in collaboration with Dr. Christine Drea and Dr. Nicholas Grebe (Drea Lab, Duke University), Dr. Virginia Kraus and Janet Huebner (Duke Molecular Physiology Institute), and the Duke Pepper Older Americans Independence Center.

Genetics Field Methods

Comparative

Brain

Epigenetic Aging

Postdoctoral Research: Comparative epigenetics of primate brain aging

Humans are distinguished from other primates in both our prolonged neurodevelopment, as well as apparently more marked neurodegeneration. Identifying molecular mechanisms underlying variation among primate brains at different ages could help us understand the origins of these defining features of the human lineage. With this goal in mind, we are taking a comparative approach to identify differences in epigenetic trajectories in several distinct brain regions across adulthood among four primate species, including humans. This research is in collaboration with Dr. Chet Sherwood (Laboratory for Evolutionary Neuroscience, CASHP, The George Washington University).

Read about this project on the Leakey Foundation blog.

Genetics Field Methods

Chimpanzee Epigenetic Age

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.

Sifaka Genome

Comparative genomic analyses of sifakas (Propithecus spp.)

In collaboration with Dr. Jeff Rogers of the Human Genome Sequencing Center at the Baylor College of Medecine, Dr. Anne Yoder of Duke University, and the Duke Lemur Center, we are analyzing the new whole genomes of four species of sifaka lemurs, the Coquerel's sifaka, the golden-crowned sifaka, the diademed sifaka, and the Verreaux's sifaka, represented by a wild male, "Dimby" from Bezà Mahafaly Special Reserve!

Sensory Genetics

 

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, including gorillas and folivorous lemurs, at sites within these genes that are experimentally known to alter taste perception in relation to diet. Such variation may reflect co-evolution with plants in the diet and digestive function. I'm collaborating on these projects with Dr. Lydia Greene (The Duke Lemur Center), Dr. Anne Yoder of Duke University, and  Dr. Brenda Bradley (CASHP, The George Washington University).

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

 

Get protocol.

Genetics Field Methods

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).

Sifaka photo credit: Sibien Mahereza

Sifaka Population Genetics

 

Beza Mahafaly Sifaka Population Genetics

This research is looking at genetic diversity, demography, and relatedness in the Verreaux's sifaka population at Bezà Mahafaly Special Reserve. This research is in collaboration with Dr. Chloe Chen-Kraus, who is studying the impact of habitat disturbance on the sifakas, and former GWU undergraduate Cassandra White. It is also in partnership with Dr. Brenda Bradley (CASHP, The George Washington University), Dr. Richard Lawler (James Madison University), and Dr. Alison Richard (Yale).

Cercopithecid Phylogenetics
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).

Email

elaineeguevara(at)gmail.com

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