Meet the Scientist Studying How Humans Started Eating Meat

A decadent beef brisket or juicy ham might grace your table this holiday season — a far cry from our ancient ancestors’ first forays into carnivory. About two and a half million years ago, early humans started using sharp-edged tools to cut through animal carcasses they came across, gobbling up any nutritious meat and marrow they could scavenge.

For “Meet a SI-entist” we chatted with Briana Pobiner, a research scientist and educator in the Human Origins Program at the Smithsonian National Museum of Natural History who studies this early culinary evolution. Pobiner shares what it’s like researching the ancient past and what she enjoys most about working with other paleoanthropologists in the field.

How did you get interested in learning about humans of the very distant past?

My first semester in college I had a meeting with my academic advisor to find a fourth class to take. I had come into college thinking I probably wanted to be an English major — I wasn't really into science. She was a former anthropology professor, and she suggested I take anthropology. I said, “I don't even know what that is,” and she explained that anthropology is the study of people. I thought, “that sounds pretty cool.” So, I took an introduction to anthropology class, and then the next semester I signed up for a class on primate evolution and behavior. I had an amazing professor and loved the course. I then went to a paleoanthropology field school in South Africa, and I was hooked!

You study the evolution of the human diet. What kind of evidence or data do you use in your research?

The cool thing about ancient diets is there's a lot of different lines of evidence to study them. What I do is look at fossils of animal bones from archaeological sites, particularly animal bones that have evidence of human butchery. That's a kind of ‘smoking gun’ of evidence that humans were there: they butchered these animals and ate them.

How does your research intersect with the museum's collections?

Most of the research that I do is actually not on collections within the museum. The collections I'm studying are mostly in museums in Africa — also sometimes in Europe and Asia. But I also have on loan a collection of modern animals from Kenya that I collected and that were eaten by big predators. Early humans competed with big predators to eat animals, so I want to also learn what it looks like when big predators eat animals – and I can do that by studying modern animal bones. Then I can look for those predator’s chewing damage patterns on fossil bones, too.

When and why did humans start eating meat?

By about two and a half million years ago, early humans started to occasionally eat meat. By about 2 million years ago, this happened more regularly. By probably about a million and a half years ago, humans started to get the better parts of animals. They shifted from just scavenging the leftovers to maybe getting earlier access to carcasses.

The “why” questions are the impossible ones to answer about the past. Whether resources were changing on the landscape or if there were just more animals around for early humans to encounter — I don't know. The “how” is probably an answerable question, though. Early humans didn't have sharp fangs like predators do, so they couldn't physically bite into carcasses. It really was the invention of technology and stone tools [that made meat-eating possible] — like using rounded rocks to bash open bones to get at the marrow inside and sharp-edged rocks to slice meat off bones.

So, it’s hard to know the “why.” What other challenges do you face doing research on things that happened such a long time ago?

I always feel like I'm trying to put together a puzzle without all the pieces. Until we have time machines, we can’t go back and make observations in the past — and I'm guessing that's not going to happen in my lifetime, or maybe ever.

I’m also always trying to take small pieces of evidence and put together a bigger picture. But there may be evidence that we're missing, and the fossil record is always incomplete. That incompleteness is probably the biggest frustration for anybody who does research on evidence from a long time ago. But it also means that every fossil has the potential to provide us with new information.

In your work, you interact with a lot of ancient bones, both from early humans themselves and from the animals they ate. What's it like holding these things in your hands and spending time with objects from so long ago?

It's amazing. When I was a PhD student, I directed excavations in northern Kenya as part of a summer study abroad program. I spent every summer helping teach undergraduate students how to excavate. We excavated butchered fossil bones from 1.5-million-year-old sites, and every time I got to pull a bone out of the ground it literally felt like reaching through time. I was touching a bone that hadn’t been touched for a million and a half years — it was magical. And even when I'm going through museum collections, every single time I look at a bone there could be a discovery in there, which I find really exciting.

Do you have any other favorite field experiences?

In addition to studying fossils, I also study modern bones that have damage by predators on them. I drive around and watch predators eat things, and then wait for them to be done and go collect the leftovers. I get a feeling like, “I can't believe this is my job.” It's fabulous. I mean, sure, sometimes I accidentally drive into a hyena den, or get chased by elephants. But you can always find something new when you're doing research.

What’s your favorite thing about the work you do?

One of the things that I enjoy most about my work is that I almost never do it alone. I collaborate with a variety of different types of scientists on different teams. I even do projects with other people who have similar expertise to me, because a lot of times butchery marks can be more ambiguous to identify. A few of us who are butchery mark specialists get together and look at the same marks to come to some consensus. And sometimes it’s even a team of 40 people with a whole bunch of different kinds of expertise when we’re excavating. I really like the collaboration aspect of the kind of science that I do.

This interview has been edited for length and clarity.

Meet a SI-entist: The Smithsonian is so much more than its world-renowned exhibits and artifacts. It is a hub of scientific exploration for hundreds of researchers from around the world. Once a month, we’ll introduce you to a Smithsonian Institution scientist (or SI-entist) and the fascinating work they do behind the scenes at the National Museum of Natural History.

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Tess Joosse | | READ MORE

Tess Joosse is an intern in the Smithsonian National Museum of Natural History’s Office of Communications and Public Affairs. Her writing has appeared in Science, Scientific American, Inside Science, Eos, Mongabay and the Mercury News, among other outlets. Tess recently graduated from the University of California, Santa Cruz with an MS in science communication. She also holds a BA in biology from Oberlin College. You can find her at https://www.tessjoosse.com/.