Searching for Human Ancestors in East Africa

ASHLEY HAMMOND: Fieldwork sometimes is not as glamourous as it might seem from movies. Fieldwork is often in a very remote place–in East Africa, for instance, it is very hot and dry. But it’s a really magical environment. There’s an element of discovery everywhere you go. You know that every time you cross that next little ridge or go down into the next gully, you might find a fossil. My name is Dr. Ashely Hammond and I am the Assistant Curator of Biological Anthropology at the American Museum of Natural History. I am a paleoanthropologist, which means that I am a paleontologist who works on the fossil record for humans and our relatives. Everyone wants to find a hominin, a human ancestor. So this involves fieldwork, trying to get out to field sites that are at the very early time periods during which hominins would have evolved. My fieldwork over the last five years or so has really been focused in Kenya. The East African Rift Valley passes right through Kenya, and this allows a lot of old ancient sediments to be uplifted and available for us to find new fossils. And the region that I work in in Turkana is especially great for this. It’s really, in my mind, the most important place in the world for studying ape and human evolution. We have sediments that span the entire range during which apes and humans have evolved. The best way to look for fossils at our sites is…essentially walking across the landscape and looking for locations where fossils are coming out of the ground. So when we find something and we recognize that it’s a hominin, typically the first thing I do is I tell everyone to stop and slowly back away. Maybe even, depending on the state of the fossil, take off their shoes, and then we can work the surface more delicately. And we walk around, or crawl around, and flag all of the different pieces of bone on the surface. And then we go through and very carefully document and collect the fossil finds. After we leave the field, we go back to the National Museum of Kenya in Nairobi where the fossils are deposited for future generations to come and study. But I want to continue to work on hominins year-round. So what we often do at the museum is laser scan different fossils and then turn them into 3D models that we can work on here in the United States. So right now I am demonstrating our 3D scanner. It’s scanning actually a monkey bone. And we can turn this monkey bone into a 3D rendering, and use that as comparative data with some of our fossils. When you’re working with fossils, often they are very fragmentary. So you have to tailor your analyses based on what you have to work with. You have to be more creative. So I developed some really advanced shape analysis techniques, things like fitting a sphere to a very fragmentary joint surface to estimate joint size. And this allows us to really compare shapes across different species or specimens in a much more advanced way than possible in the past. I’m really focused on trying to piece together the evolutionary history of the ape and hominin pelvis. The pelvis is really informative about the biology of an animal. It can tell you about what species you’re looking at. It can tell you about whether or not you’re looking at a male or a female. Sometimes you can even tell if an individual has given birth. And you can even get information about where an individual is from. I still think it’s a really big question about what the starting point for the human lineage looked like. What kind of behaviors we were using, how we became bipedal and so forth. So the only way to really get at that question is to get out and do more fieldwork. I’m very excited to get out with me and my crew and see what kind of fossils we can find.