The Ethics of Studying Bones: Learning about Bioarchaeology with Stacy Drake

Stacy Drake is a bioarchaeologist who works as a collections specialist in the area of repatriation for the Field Museum. Her research in the past has focused on the ancient Maya of Belize and their burial practices. Today, much of her job involves NAGPRA. The Native American Graves Protection and Repatriation Act, enacted in 1990, was created to protect indigenous remains and artifacts and initiates the return of some remains that had been sent to museums, universities, and archaeological collections. We talked about what it’s like to work with human remains, how Stacy learns things about an individual’s life based solely on their bones, and how the field has changed. The views described here reflect her own personal opinions and experiences; she doesn’t speak as a representative of the Field Museum. 

What first interested you in studying human remains?
I was always that child who loved skeletons and bones. My parents, whether or not they found that frightening, were very supportive. I initially wanted to be a paleontologist and went to undergrad to pursue a geoscience degree and quickly discovered that hard math and science was not my forte. I thought, archaeology is cool, maybe I’ll switch over to be an anthropology major. I started taking classes in the Ancient Maya and I got particularly interested in cultures of Central America.

Through the guidance of my graduate advisor, I was taken under the wing of the project osteologist for an archaeological field school in Belize and developed from there. That’s how I got interested in Maya burials and Maya human remains. Then I got a job working at an archeological repository to document their osteological collections and that’s where I started getting exposed to NAGPRA and the ethics of human remains. I really enjoy talking to people about archaeology and especially enjoy getting into sticky conversations about the ethics of archaeology and human remains. I found this niche of getting to work with collections that have human remains, but also getting to be involved with descendant communities. 

Can you describe your job?
It’s just like the TV show Bones but without the sexiness or the FBI or the fancy tools. Really, it’s just me working with human remains, most often from prehistoric or very old contexts, and using their skeletal remains to understand a little bit more about who they were in life. In archaeology it’s very rare to get individual information. A lot of times you talk about a culture using a whole bunch of artifacts, or grand architecture at a site, to understand the culture as a whole. But with bioarchaeology, using human remains gives you a really unique perspective of one person’s experience.

My day-to-day is looking at the skeletons and reading the bones to determine how old someone was when they died, were they male or female—biological sex, not gender—and then trying to see any indications of disease or trauma. It’s trying to piece together their lived experience. [More broadly], bioarchaeology as a study looks at human history not just from the bones, but also from their contexts—where they were found, what was buried with them.


It sounds more intimate than digging in the ground for artifacts or old stone tools.
I think it can be. It’s really easy to piece together your own narrative for a site or an artifact that you’re working with, or a collection of artifacts. But in bioarchaeology you’re looking at the remains of an actual person.


How do you protect the remains from further damage when you’re working with them?
The places where I have done field work, there’s already a lot of damage, unfortunately, just from the surrounding environment. You try and move quickly. We use a lot of tarps to keep rain and critters out, and then do lots of documentation. Typically with archaeological excavation as soon as you remove something, you’ve removed it forever. You’ve altered that context. So we do lots of documentation, photos, and maps to preserve the original burial context as best as possible.


Something I’m interested in is taphonomy, or what happens to the remains after death and why some bones fossilize while others don’t. Can you talk about how that influences your work?
Most of the material that I work with is too young to be fossilized. But a lot of the remains you’re talking about in your blog, that’s gonna be dependent on the preservation. So if they were buried quickly or in really mineralized contexts [they’ll fossilize].

The remains that I work with typically haven’t had enough time to become fossilized. In the environments where I have worked with human remains—we’re talking about jungle environments—the humidity, the bacteria in the soil, they really eat away at the bone. A lot of times when I’m looking for disease on bone I’m looking for lots of porosity, or weirdly altered texture of the bone, which can happen in certain environments. You can get insect trails in the bone that make it hard to determine whether you’re looking at something that happened before the individual’s death or something that happened afterwards. Taphonomy is a real pain in the butt.

It gives you a lot of pause. Looking at a fractured cranium—especially when you’re working in a museum context when you haven’t been excavating the individuals yourself—you’re trying to figure out, Is this something that happened to the individual when someone was excavating them? Did a tree root grow through the bone and fracture it? Or was this something that happened before or around the time of death? It takes some time to piece those out and document them.


Are there things you look for to determine whether injuries happened before or after death?
A lot of the things that I look for are coloration and shape. With fresh bone that’s still wet, something that would’ve happened to an individual at or around the time of death, the bone isn’t going to be as friable when it breaks. If I see a fracture and the edges are really jagged and the bone along the edge of the break is lighter in color than the bone around it, that’s an indication to me that it happened after the individual died. If it’s [an injury] that happened weeks or more before the individual died, then you’re going to see the bone remodeling, and that’s something else you’re going to look for.


Can you tell the difference between diseases, or do you just indicate that there was some kind of disease involved?
More of the latter. I’m not formally trained in pathology, in understanding disease processes and how they affect bone. Mainly what I see is certain ways that bone is reacting that might be an indication of a certain disease or infection. But most of the time with the remains that I work with, you’ve got reactive growth or bone loss where something is happening to the bones, but it’s really hard to pinpoint what that process might be without the assistance of DNA or other characteristic features.


How do you go about the process of aging people from their remains?
It’s easier with children to get that narrow age range. With children, I look at the way the teeth and bones are developing – certain teeth tend to develop and erupt along a relatively reliable timeframe, and long bones and other skeletal elements will fuse around certain known ages as well. With adults, it’s best if you can have an understanding of the population in general. I work with a lot of populations that are indigenous to the Americas and we use the teeth a lot. Teeth are going to wear a lot differently in populations that are grinding their food with stone, or living in really sandy, gritty environments that’s going to wear their teeth down faster than, say, European populations or many populations today.

A lot of times I don’t have the bones from the pelvis to utilize. That’s a more reliable area of the body that has characteristic features you can use to help determine age. You can also look at cranial suture fusion, but that is not as reliable either. So if I’m lucky I’m getting about a ten-year age range on an adult, if not more.


That seems pretty close.
But sometimes a decade could mean a lot. We have these generic terms of young adult and middle adult and old adult. And most of the time even if I’m getting a narrow age of ten years, that’s straddling two broader categories. It’s not super precise in the ways that I use it, but it narrows it down.


Why does the precision matter?
For me it’s just wanting to get as much right as I can. I’m trying to provide information on individuals who can no longer speak for themselves. When you’re working with descendant communities there might be different cultural practices or ways in which they want their ancestors to be treated based on their age. So it’s a combination of wanting to be as accurate as possible, and trying to do right by the individual and not be incorrect about them.


How has DNA testing changed the field of bioarchaeology?
It’s such a big topic right now, it’s hard to talk about. In my dissertation research I used some DNA samples and I know that there’s work where I think DNA can be really useful and interesting. But at the same time it’s also a slippery slope. How much can you really say using DNA samples? How much can you say when you’re only looking at a sample size of a few individuals? And there are problems where the public sees DNA as an end-all be-all. A community or archaeologist can argue one thing, but if a geneticist says something else, well they’re using DNA so they have to be right. I use it kind of hesitantly. In my current work with more focus on repatriation, it’s even more complex because a lot of indigenous groups are wary of the practice or they want to be the leaders in that type of research.


How do you deal with repatriation and helping communities retrieve the remains of ancestors?
A lot of it comes down to actually communicating with the descendant communities. Human remains hold a lot of scientific value, they can share information to the general public about human history, but many communities might believe that the ancestors are still aware of what’s going on around them. Anyone might see them as just a collection of bones, but to other people they are very much still alive. So having open communication with descendant communities and letting them make decisions and lead the conversation is one of the best ways to move this type of work forward.

For better or worse these individuals are at museums, universities, archaeological repositories, and the best way to work through that is to accept that it’s the reality and be willing to work with each other to figure out how to remedy it.


Do you think we’re moving past the idea of bones being the property of science and recognizing them as former humans?
I do think that most people who work with human remains understand and grasp the humanness of the remains. But we can always do better, and I think it is extremely important that the general public has a growing sense of this as well. Collections of prehistoric/historic remains from Europe or other regions are often not considered problematic due to different views of modern-day people from those areas, but many other communities hold a lot of religious or spiritual significance with human remains. And there are plenty of problematic origins for human remains collections. Many early anatomical collections were created using the remains of institutionalized individuals (prisoners and/or patients deemed mentally ill), individuals who were too poor or without family to pay for burial, and other disenfranchised individuals like African Americans. So I think it’s really important that people who interact with human remains on a daily basis understand these circumstances, but also do what we can to ensure that the general public consider these circumstances as well. I do see a lot more interest in ethical approaches and open conversation and really trying to overcome the challenge, and seeing human remains as people who need to be treated with decency and respect. 


If you could travel in time for research purposes, which period would you like to visit?
I think about this a lot. For my own personal research interests it would be extremely useful to go back to certain time periods of the ancient Maya. With the ancient Maya that I have studied, we don’t find cemeteries, we’re finding burials of one or maybe a couple individuals at a time. So why would you bury someone in a certain way? That’s especially [a question] with the ancient Maya because there’s not just one general trend in which people were buried. It always makes me wonder, how much does that tell you about the interred versus what people’s burial practices were? What was important to them versus the person being buried?

I also have a weird interest in 1700s-1800s Europe and understanding what life might have been like then. But at the same time I also know that I probably would not survive very long in those time periods. I’ve seen some of what can happen to the bodies of people living in pre-antibiotic ages and I don’t know if I actually want to put myself in those types of situations.

Feet On the Ground: Exploring the Pleistocene Environment with Geologist Gail Ashley

Credit: M.Lopez-Herrera via The Olduvai Paleoanthropology and Paleoecology Project and Enrique Baquedano

Credit: M.Lopez-Herrera via The Olduvai Paleoanthropology and Paleoecology Project and Enrique Baquedano

Gail Ashley is a geologist and the director of the Quaternary Studies Program at Rutgers. She’s been working in paleoanthropology since 1994 and has conducted extensive field research in the East African Rift Valley, especially on the hydrology and ancient environment of the region. We discussed her work, including the role of water in human evolution and how geologists try to understand landscapes of the past.


Why did you decide to focus on water to study human evolution in the East African Rift Valley?

My whole approach right from the beginning was looking at resources, especially water. If you spend any time in Africa, one day is a problem without water. So I was thinking of smaller spatial scales, shorter time scales, and looking at things from a much higher resolution, from the point of view of what I call “bare feet on the ground,” people having to survive on a daily basis.

The record that’s preserved after 2 million years—there is not always a lot. Sometimes you have to use a bit of creativity to connect the dots, and then figure out how to prove that scientifically. It has been getting more arid through time, but that’s operating on such a long time scale that it couldn’t possibly be a major factor to me. To me, it’s a day-to-day basis that affects whether people live or die, and it’s that long-term accumulation of day-to-day activities that leads to natural selection and evolution.

I find myself sometimes a voice in the wilderness in trying to talk about things at a scale like that. I think water is key. Water for drinking, obviously, but also water was important in terms of resources, the plants and even protein sources that would be associated with springs and wetlands.


Does the geology of freshwater resources play any role in the size of the populations for early hominins?

There is a logical connection to that. Everybody envisions the populations to be relatively small. They’re being modeled after things like chimpanzee troops and other types of primates that tend to occur in relatively small groups. People could also look at the size of groups of the few hunter-gatherer humans that we have now, like the Hadza. But I I’m not an anthropologist, I’m not a biologist, and so I have to go by what I’m being told.

An area can only support so many people, particularly if the springs are small. That’s what I’m trying to figure out, why the springs tend to be relatively small. It’s all connected with the geology: how fast the water can flow, what the recharge is from rainfall, the rate of flow out of the spring and how fast it evaporates. A spring that’s small and slow-leaking can actually provide quite a bit of water, whereas one that’s flowing faster might evaporate more quickly.


How did volcanoes and earthquakes impact the populations?

The tectonics associated with the Rift Valley are an ongoing thing that certainly affect the topography and where groundwater exits, so it’s really important in connection to the plumbing, so to speak. In terms of faulting or earthquakes, those do not operate on the timescale that’s going to affect a person that lives 20 years. They might feel an earthquake or see the effect of a fault somewhere, but the only thing that might impact them would be volcanism. Volcanism has occurred and when it does it can be very dramatic and have a high death toll, but that’s local. The land and people tend to recover from it. Overall, tectonics is something that happens as an ongoing part of the system, but I don’t think it really has a major impact on the individual hominin or hominin family, on a day-to-day basis.


How do you use geology to answer questions about food sources and water?

I am a sedimentologist, so I spend most of my time looking at rocks that start off as loose sediment like sand, silt, or clay, and then get cemented with time and turn into rocks. The record of the homimin environment is encased, or archived, as I often say, in these sediments.

Some of the things that are archived are organic materials, and that organic material is a record of what was on the land’s surface: what microbes were there, what plants were there, and in some cases, what animals were there. It made a lot of sense to me, when I was trying to reconstruct what the land’s surface would’ve looked like, to find out if there were trees there. Were they in the middle of a forest or a small woodland? Was it a grassland with scattered acacia trees like everybody seems to talk about? When a hominin was looking around, what would he see? The way to determine that is by looking at the organic matter.


What’s the most useful tool for your research, the thing that people might not understand about using geology to study the landscape?

The most fundamental thing that is important to the research that I’m doing, is that you need be able to correlate beds over great distances. Which means the stratigraphy—your understanding of the layers and how they vary—has to be well documented. If you don’t know that you’re within a time horizon and you slip off into something that’s 10,000 years older or younger than you think, then you’re not reconstructing the landscape at all. You’ve got a hodgepodge.

For the work I’m doing, precise stratigraphy is really important. If you don’t have good geology, or good precise locations of where your samples are coming from, then your samples aren’t worth anything. And if you’re samples aren’t worth anything, the data that comes out of them aren’t either. So it all boils down to good field work.


What are the big unsolved questions for you? Is there anything that drives your research?

One of them is the quandary that many of these hominins, or at least Paranthropus, had teeth that appear to have a geochemical record of them living on a savannah or eating grass. Which doesn’t make a lot of sense. For one thing, there’s not a lot of nutrition in grass. This is because scientists have been very narrowly associating the isotope signature that appear in the teeth to be only grass. What we’re finding is that there are a lot of other plants that have a similar signature but can occur in different environments. There are plants that occur within springs that have a signature which is similar to the grass.  

Knowing if it’s grasses or wetland plants makes a big difference, because one of the pervading ideas about what drove evolution is the aridity forced hominins out of trees to go walk on the grassland and eventually hunt. And it might very well have been that they lived in an entirely different environment. I’m hypothesizing that they were tied to springs, and that they were eating vegetation that provided a signal that was similar or the same to what would’ve been derived from eating grass. This would change the whole idea of how people evolved, what was the driving mechanism for their evolution. But it’s not very well worked out yet.

What you would like to see if you traveled back in time?

If I could go back in time, I would like to see what kind of movements hominins did on a daily basis and on a seasonal basis. I’m pretty sure that hominins did move around on the landscape and that a lot of the water that we’re talking about, the water I’ve been studying, is in low areas. I think hominins might’ve moved down in low areas to acquire meat and then moved back up on the highlands. It could’ve been done a daily basis, but definitely on a seasonal basis. I suspect they might’ve moved up higher on the slopes where it might’ve been a little cooler, but then they would come down low, into the valleys, because there would be more grazing animals and that’s where the springs often disgorge, at the bottom of slopes. So there would be animals and opportunities for scavenging or hunting.

What would you be afraid of running into, if you traveled back in time?

For the most part carnivores are not so worrisome to people, they much prefer animals to eat. Of course, if you meet one at the wrong time it’s not good, but for the most part they prefer getting a good chunk of buffalo. But snakes—I could do without snakes, thanks.

August News Roundup

It's been a busy month in the world of archaeology and anthropology. The biggest news came from Siberia, where researchers managed to extract and analyze DNA from a 90,000-year-old bone. Turns out this is the first individual ever discovered to have parents of two different species—a Neanderthal mother and a Denisovan father

Some other interesting stories: What headlines got wrong about a new study on Homo erectus and its adaptive techniques. How experimental archaeology is teaching scientists more about the environments and tools of California's early inhabitants. Using tree rings to date a volcanic eruption in Greece. A fossil previously believed to belong to a bat actually comes from an ancestor of lemurs, and might rewrite prosimian history. And a massive burial site in Kenya from 5,000 years ago shows how the pastoralist society shared the work of building the monument.

Finally, for the podcast-listeners among us, there's a new series out called "Sapiens: A podcast for everything human." The first episode tackles DNA and genealogy and what makes us us.