Christopher Schmitt, professor of anthropology and biology, studies the evolutionary genomics of adaptations to ecological extremes in wild non-human primates. His work focuses on characterizing evolutionary patterns in the developmental genetics and physiology of various savanna monkey populations.
How and when were you introduced to evolutionary biology?
I grew up in Wisconsin and attended Milwaukee Public Schools as a kid, which was a great education. My interest in biology started pretty early – I was always interested in animals, could not get enough of National Geographic documentaries and magazines, and even designed a circuit board in 4th grade that would light up when you matched mammalian gestation lengths with the proper animal, underscoring body size as a hint (so my interest in life history theory goes way back)! I first formally learned about evolutionary biology in my high school biology class, the same year some members of the MPS school board made a failed attempt to replace our college-level biology textbook with a pseudo-scientific Creationist version. That scandal – which our high school biology teacher detailed for us; he was an excellent instructor – underscored for me how revolutionary and liberatory the study of evolutionary biology has been, and really honed my focus and interest on evolution as a framework for understanding biology and behavior. Of course, what really sealed the deal was winning a scholarship from the Earthwatch Institute my junior year of high school to help out on a wild primate field study run by Dr. Gonvindasamy Agoramoothy. That funding allowed me to spend a month in northern Argentina with an international team of volunteers collecting feces and urine from wild black and gold howler monkeys (Alouatta caraya) in Argentina to better understand how hormones might correspond to major behavioral events like intergroup fights, matings, and infanticides. It was an amazing month: two howler monkeys mated right over my head, I was urinated on repeatedly, and I walked into house-sized communal spider webs several early mornings trying to get to the monkeys. Realizing that evolutionary biology could also give me some amazing adventures, I was hooked.
What has kept you in the field of biological anthropology?
I was actually an English Literature and Zoology double major in college at University of Wisconsin; I honestly had never heard of biological anthropology until I was a junior. I really do wish I’d come to it earlier! Our field is rooted in Franz Boas’ desire to make Anthropology in the US a comprehensive understanding of what it means to be human – culturally and biologically, both today and in the deep past. Although my focus is on evolutionary biology, understanding that in a human context means we must also think through cultural phenomena as integral parts of the environments in which we evolve. This mission has lost its way, at times… many physical anthropologists in the early 20th Century contributed to scientific racism, and so to many of the biological misunderstandings and falsehoods that White supremacists nurture to make themselves feel superior. In today’s academic landscape, biological anthropologists have a moral duty to counter these misguided notions (as outlined and exemplified in the American Association of Biological Anthropologists’ Statement on Race and Racism). Although my research is on wild non-human primates, my teaching focuses on this history so that students at BU can identify, deconstruct, and counter these ideas. All in all, biological anthropology’s combination of social science and biology is really powerful, not only for understanding how we evolved a capacity for culture but also for understanding how social and cultural forces can interact with understandings (and misunderstandings) about biology and evolution in ways that can affect our social and physical well-being. I briefly left biological anthropology after my Ph.D. to join the Center for Neurobehavioral Genetics at UCLA to learn functional genomics, but quickly decided to come back. Evolutionary biology without the humanity just doesn’t make sense to me.
What about non-human primates interests you and how do they inform your research?
Working with wild monkeys is inherently rewarding…with long-term fieldwork, in particular, it’s like watching a soap opera from day to day as the monkeys fight and hook up and generally cause drama – all while running through beautiful montane cloud forests. It’s pretty amazing. Of course, I study the monkeys because their behavior and biology can be good models through which to better understand human evolution (in ways that are difficult or impossible to do in humans). This is why, for example, I study savanna monkeys (Chlorocebus spp.) as a model for the evolution of human metabolic disorders. For a long time, we’ve guessed that humans might have a predisposition to metabolic disorders as an evolutionary response to famines. If food is frequently scarce, it would be beneficial to build up body fat quickly whenever food is available, allowing us to survive off fat stores. If there were genetic variants that conferred such a trait, then over time such these thrifty genotypes would become common anywhere where famine was common – today, however, when food can be very rich and almost always available, these thrifty genotypes might lead to obesity. Studying whether this hypothesis is true has been difficult in humans – people aren’t often honest about their diets, and it would be unethical to create an experimental famine. Savanna monkeys, on the other hand, live in a variety of environments, we can watch what and how much they eat, and in captivity we can experiment with their diets. In my captive research, I’ve found that the genetic systems in savanna monkeys that result in obesity are similar to those in humans, so I’m now looking to wild populations in South Africa to see how those genotypes implicated in captive obesity actually change expression patterns in response to drought to see if the hypothesis works.
What sort of behavioral adaptations has your research focused on?
A lot of my fieldwork has focused on the behavior of infant and juvenile primates. Aside from being adorably awkward and cute, this phase of life is a fascinating time during which later adult behaviors and physiologies can be programmed or canalized by experience and the environment. Now, of course, I focus more on genetic questions, but behavior is still an important part of the picture! A great example comes from the work of my recently-graduated Ph.D. student, Christian Gagnon. He studied the evolution of the UCP1 gene in savanna monkeys across Africa. UCP1 is only active in brown fat – located mostly in our neck, upper back, and around our internal organs, brown fat cells literally burn off the fatty acids inside them to create heat when we get cold; the UCP1 protein, thermogenin, is the engine that drives this process, called non-shivering thermogenesis. Christian’s work found clear signs of selection on UCP1, but not in the coldest areas as we expected… it was only on the southeast coast of South Africa. In addition to having cold winters, that area is at a much lower elevation and so the sun is weaker… but why should that matter? Then we remembered: savanna monkeys sunbathe on cold mornings, sometimes for hours, to help themselves warm up. We guessed that the weaker sun on the coast makes sunbathing less effective as a way of staying warm, so monkeys there have a greater need for UCP1 to heat up in the winter. Behavior intervening in evolutionary patterns in this way is called a Bogert Effect, like here where thermoregulatory behaviors interrupting selection on thermoregulatory physiology. It’s a really cool outcome that reminds us that even when studying genetics, knowledge of the whole organism, including behavior, is crucially important for understanding evolutionary patterns.
Interview by Kelly Broder (COM’27)