UNM anthropologist uses chimpanzees as model to understand aging

UNM anthropologist Dr. Melissa Emery Thompson is leading a project funded by the National Institute on Aging examining the human aging process by studying one of our closest relatives — chimpanzees. 


The project focuses on how chimpanzees age and what sort of factors affect their health as they get older. Ultimately, the goal is to figure out what constrains the lifespans of chimpanzees and how this can be applied to humans.


Emery Thompson’s research looks at the factors that affect fertility, mortality, aging, sickness, growth and development. 


CHmPP Lab co-director Melissa Emery Thompson observes chimpanzees at the Kibale National Park. Currently, she visits the Ugandan field site twice a year for a few weeks to collect data.

“My big question has been how did the human life cycle evolve, and we’re using apes as a model for understanding the baseline of what our ancestral life cycle was like,” Emery Thompson said. 


In places like the United States, some of the most common age-related issues encountered include heart disease, cancers, and obesity related diseases. 


Outside of the industrialized world, these basically don’t exist. The suggestion is that if you live an active lifestyle and you have a natural diet, like chimpanzees, that some of these things we think are inevitable diseases of aging are probably not a part of our evolutionary past, Emery Thompson said. 


“So right now we’re trying to figure out what does aging look like in a wild chimpanzee, and if it’s not this pattern of heart disease, inflammation, and obesity then what factors do affect health and wellbeing under these conditions,” Emery Thompson said. 


Along with this, Emery Thompson is collaborating on another related project which deals with leadership. With help from researchers at the University of Michigan and Tufts University, Emery Thompson is studying chimpanzees who exhibit strong leadership qualities. 


“You can be dominant because you’re aggressive and have the physical strength to intimidate others, we know primates do that, but there’s not been any literature on whether there are other ways primates can be leaders or whether that’s a unique human characteristic,” Emery Thompson said.


Humans can also assert dominance through intimidation, but leadership can also be attained through having particular set of skills, knowledge, or something else of value.


 “We don’t know the extent to which that’s true in other primates, or what characteristics might predict these other kinds of leadership,” Emery Thompson said. 


A community of chimpanzees moves through the forest floor. There is currently 57 chimpanzees in the community Emery Thompson is monitoring. Photo courtesy of Ronan Donovan.

Seeking to try and answer some of these big questions has led Emery Thompson to observe wild chimpanzees in their natural habitat for years.


“My role in this big project, the Kibale Chimpanzee Project, has been to develop what we call a physiological monitoring program or health monitoring program. We have a field site in Uganda that’s been running for just over 30 years, it was established by Richard Wrangham, my phD advisor at Harvard, and now I help manage it with (UNM Associate Professor of Anthropology) Martin Muller and Tufts professor Zarin Machanda. There are 57 chimps in the community we study right now, so we’ve got, for some of the chimps, 30 years of data on everything they do, what they eat, interactions with others, etc,” Emery Thompson said. 


Emery Thompson currently visits Kibale National Park about twice a year for a few weeks to check in and collect data. While away, field staff collect data on the chimps everyday from the minute they wake, to when they go to sleep. As well as observation, the data includes biological samples such as urine and feces, all collected non-invasively. 


An adult chimpanzee nibbles fruit of a branch. The chimpanzees in the community spend about 60% of their day eating. Photo courtesy of Ronan Donovan.

“They’re comfortable with us being there but we maintain a distance of about 15 feet at all times so that they basically ignore us and do what they’d be doing. They spend about 60 percent of their day eating, the rest of it is moving to get food, then they tend to spend the rest of that interacting with each other,” Emery Thompson said.


Another side project stemming from this observational research follows outbreaks of respiratory illnesses in chimpanzee colonies caused by human contact.


“About one-quarter of the chimps in our study group  have died from respiratory illnesses. This is part of the reason we keep a 15-foot distance. When a human disease gets in there, nearly all the chimps get sick and some of these epidemics, in a month, can kill 10 percent of the population,” Emery Thompson said.


Emery Thompson and her colleagues identified the pathogens responsible and were able to sequence them and compare them to other circulating viruses in the area. This is important because so far three human viruses have been identified as the cause of three independent outbreaks, killing 25 chimps in a month in a neighboring chimpanzee community, Emery Thompson said. 


When Emery Thompson is not on the field you can find her in the Comparative Human and Primate Physiology Center (CHmPP) Lab.


CHmPP co-director Emery Thompson analyzes samples in the lab. CHmPP Lab is one of the few service centers of its kind whose speciality relies on non-invasive approaches. Photo courtesy of UNM Anthropology Dept.

CHmPP Lab is one of the few service centers of its kind whose speciality relies on developing non-invasive approaches for scientists to study the link between physiology and behavior in their research, Emery Thompson said.


CHmPP lab was the creation of Emery Thompson and Dr. Martin Muller when they arrived at UNM in 2008.  Fifty to 60 percent of work done in the lab is directly related to the wild chimpanzee project; the rest of the work comes from other collaborations, Emery Thompson said. For example, they work with Drs. Steven Gangestad and Marco Del Giudice in UNM’s Department of Psychology, as well as several investigators from North Campus.


“These studies are  usually trying to understand how biology affects behavior, or how things that happen in the social or physical environment affect our bodies,” Emery Thompson said. 


In regards to collaboration, Emery Thompson said she is glad to have made the move to PAÍS  in hopes that it will increase collaborations across campus. 


One existing collaboration is with Dr. Sherry Nelson and the Center for Stable Isotopes, where chimpanzee urine is being analyzed for isotopic signatures of diet and nursing behavior. With the help of the Center for the Advancement of Spatial Informatics Research and Education (ASPIRE), Emery Thompson says they’re going to be able to make high quality maps of the chimp ranges and be able to better understand individual variation and decisions they make in their habitat. 


“It’s really hard when you’re all in different places, so there’s going to be a really good interface between these different labs that make up PAIS. UNM has a lot of amazing stuff. Sometimes when you’re in your own little world you don’t know that there’s somebody that can really help you out in another place, so I think that’s the real potential here,” Emery Thompson said.