Irene Smail, Ph.D.

Researcher’s study of monkeys and humans blends anthropology, anatomy

What can monkeys teach us about what it means to be human? That’s what Irene Smail, Ph.D., who joined the West Virginia School of Osteopathic Medicine (WVSOM) in 2022 as an anatomy professor, hopes to find out through her research.

Smail’s work is a continuation of research she began in graduate school. After completing an undergraduate degree at the University of Wisconsin-Madison, Smail earned M.A. and Ph.D. degrees in anthropology from Arizona State University. Before joining WVSOM, she was a postdoctoral scholar at the University of Southern California’s Keck School of Medicine, where she taught anatomy to both master’s degree and medical students. 

During her time at Arizona State, Smail joined a long-running project whose aim is to answer questions about the disappearance of the pre-human species Australopithecus afarensis and the emergence of early humans leading to Homo sapiens. As a member of the project’s paleoecology team, she began traveling to Ethiopia to search for fossil monkeys. That work has allowed her to conduct her own research into how communities of monkeys have changed over time in response to environmental change.

Smail measures fossil monkey teeth — from the project in Ethiopia and from U.S. museums — to examine how changes in diet may have affected changes in the shape of teeth. She explained that a full understanding of the changes will require measuring other bones as well.

“We can use our measurements to figure out what they were eating, and look at differences in teeth to determine if they were eating different things,” Smail said. “But because teeth are not the only thing you use to eat, I’ve started to add other measurements. This past summer I went to the Smithsonian and photographed monkey skulls and jaws. I use the photos to make 3-D models in my lab, and then I use the models to take geometric measurements such as how curved the jaw is to try to see if it’s related to diet.”

Because monkeys and humans have lived alongside one another in Africa for about five million years, Smail can compare fossil monkeys with fossil humans over various time periods to identify what makes humans different. She said she’s interested in understanding how humans came to have their physical form.

“As an anthropologist, I’m interested in understanding not only modern culture and society, but how we physically became modern humans, and that’s where anatomy comes in,” she said. “Knowing how we became this way gives us a better understanding of what humans look like on the inside.”

Additionally, Smail plans to study how human behavior is changing the behavior of modern-day monkeys.

“I’ve started looking at Asian monkeys, because we know a lot of deforestation is happening there and habitats are being changed. I want to figure out whether the monkeys are eating different things now because there are different foods available. Some animals are going extinct because humans are hunting them and cutting down trees. But macaques and baboons are increasing in population because they’ve figured out that humans have garbage dumps where they can find human food that’s easier to eat. So we’re seeing changes in them that, in a million years, might make them a different animal,” she said.

Since joining WVSOM, Smail has presented a conference abstract (“Patterns of Dental Macrowear in Living and Fossil Cercopithecid Primates”) at the American Association of Biological Anthropologists and visited the National Museum of Ethiopia — where fossils are taken after they are discovered — to prepare a manuscript on fossil monkeys. As a WVSOM faculty member, she hopes to involve students by inviting them to assist with data collection and analysis.

“Our students don’t have time to go to Washington, D.C., to visit the Smithsonian. But part of my goal in building the 3-D models is to give them a chance to use their anatomy training in form-function research,” she said. “I can tell them, ‘You know what this part looks like on a human. It looks the same on a monkey. These measurements will help us figure out how the anatomy influences what they’re doing.’”

Smail’s “Community Niches and Evolution of Generalist Primates: A Preliminary Assessment of Plio-Pleistocene Cercopithecidae in Africa” appears in Volume 2023, Issue 2 of the journal PaleoAnthropology. Ultimately, her research is about answering big questions regarding humanity, a pursuit that requires an intermingling of the disciplines of anthropology and anatomy.

“I want to figure out what makes humans unique. We don’t know when that happened. I’m trying to find a time when you see small changes happening in monkeys and a big change happening in humans so that I can point to that time and say, ‘Here’s the point when humans can do something monkeys can’t do,’” she said.