Bioarcheology: Peopling the Past

What drew you to paleopathology?

I wish there were an easy answer to that question!

My dad was a doctor, so I always had an interest in health and disease. My mother spurred my interest in history and past cultures; she often spoke about how she felt that the Native Americans had been given a rough deal. I thought I could marry the two interests by studying archeology – but, when I was in training, I found that people talked a lot more about material culture than they did about people. As a result, I’ve always been intrigued by “peopling the past,” which is what I call “bioarcheology.” I have the dubious distinction of having coined that term (as it is currently used) in the 1970s.

A key aspect of investigating the people of the past is studying health and disease. In paleopathology, we look at the issue in two ways: some people focus more on community health, whereas others focus on the history of specific diseases and their co-evolution with humans and the environment. We’ve had a real revolution on both sides with the advent of molecular approaches that enable us to investigate previously intractable questions about certain diseases. An example close to my own heart is tuberculosis. In graduate school, I began looking at this peculiar American tuberculosis that we find prior to first contact by Christopher Columbus in the era of exploration. How did such a disease get to the Americas in the absence of transatlantic human interaction? Nobody knew – but I wanted to find out.

My colleagues and I played a key role in identifying the molecular signatures of that disease, which helped us to differentiate it from other strains. Then, we discovered that it wasn’t brought over the Bering Strait by humans, as we originally believed – instead, it was brought to South America by pinnipeds, such as seals and sea lions! And that’s what I love about my work; there are always surprises. As a result of this particular surprise, we’re now trying to chart the spread of tuberculosis through the Americas from its point of origin.

What role does paleopathology play in the clinic?

I have colleagues who work in evolutionary medicine, and they have been shocked to find that, when they explain their work to other medical professionals, they sometimes have trouble getting the “evolutionary” part across. I’m delighted to hear of the broadening of perspective in pathology training. Paleopathologists are usually the “history of medicine” people – relegated to the far corner – but our input in medical training is becoming increasingly valuable as science becomes more and more interdisciplinary; anthropologists, social scientists, and others have an important role to play. If we’re really going to have a discipline called paleopathology, what kind of training (or, at least, core knowledge) should its practitioners have from each relevant field? The interdisciplinary angle is one we can’t ignore, because the diagnosis of a disease in the past, however exquisite, can be wrong if it’s not interpreted in the archeological or historical context.

Naturally, one identifies disease based on one’s experience, but I think something that paleopathologists bring to the diagnostic table is a knowledge of the history of disease and the possibilities each symptom cluster contains. When I first started work at Northwestern University, I spoke to one of my clinical colleagues about our differential diagnoses for tuberculosis, and specifically the fact that the disease could mimic blastomycosis. He told me flat-out that blastomycosis had never been diagnosed in the Midwest – but I knew that some of the earliest cases were from the Chicago area, because I had read the literature and knew the history. That was a practicing pathologist – so if a patient with blastomycosis had come into his clinic, he might have missed the diagnosis simply because he didn’t know the history of the disease. That’s just one example of how a broader perspective can help in the clinic.

How are new advances shaping paleopathology?

Molecular approaches are giving us a new perspective on a wide range of diseases. To stay abreast of the newest tests and technologies, we have a strong interface with research and clinical biology. The clinic affects our work in other ways, too; for example, we have to be wary of the clinical picture since the antibiotic era, because administering treatments has changed the incidence, prevalence, course, and effects of infectious diseases – and changed the pathogens themselves, of course. If we’re going to model peak time for an infection, though, we certainly benefit from the clinical perspective!

In my opinion, the next breakthroughs are going to be i) looking at the immune system, ii) working more effectively in oncology, and iii) greater appreciation for the role of non-human hosts in the origins and evolution of infectious diseases. We’re starting to deal more with genetics and the development of various cancers in the past, so I’m excited to see where that takes us in the future. I think paleopathology gives all pathologists a deeper appreciation for the changing patterns of disease and how they reflect our natural and human environments. In terms of health delivery, I think we draw in elements that illustrate the need for every step of the disease control process. The ability to cure a disease is, of course, essential, as is the ability to identify it. But unless you have healthcare delivery, you still have an issue. It’s no use knowing what the disease is and how to treat it unless you can actually act on that knowledge! And that depends on how the diagnosis and treatment are delivered – which, in turn, depends on (among other things) cultural context.

What I find particularly striking right now is the degree to which health and healthcare involve the interactions between humans and their environment. I’m currently looking into the species-jumping ability of some pathogens – something that affects not only animal health and conservation, but also human health. For example, in India, where troops of monkeys inhabit temples that are visited by tourists, researchers have documented the spread of pathogens from tourists to monkeys and back again. Such interactions have clear implications for healthcare and epidemiology now and in the future; paleopathology can make its biggest contributions to the clinic by improving understanding in this area.

What’s next for the field?

I’m in charge of a large project in Greece, where I’m pushing for large-scale screening of skeletons from the Archaic Period site of Phaleron for both primary tumors and secondary metastases. People generally don’t do such systematic screening because it’s expensive and time-consuming, but it’s the only way we’re really going to get a picture of cancer prevalence in the past. From there, we can start looking at the genetics of the oncologic changes we see. Sometimes, you need to look back to see the way forward!

As Editor-in-chief, my developmental goal for the International Journal of Paleopathology is to bring together three historically distinct branches: human paleopathology, animal paleopathology (which tends to develop through archeofaunal analysis and has a separate intellectual history to the other branches), and then the “mummy folks,” who tend to be clinicians focusing on specific diseases in the developing field of mummy science. Trying to draw those three together and give them a venue to publish and to interact is certainly a work in progress, but I think there’s some really interesting potential, if we all work together. When it comes to important questions, collaboration is the name of the game.

Have you encountered any misconceptions about paleopathology?

The two most common misconceptions are that we deal with dry bones and isolated cases. As to the first, we study not only skeletons, but also mummified remains – and all within archaeological and historical contexts. And as to the second, although we do investigate isolated cases of disease – which can be important when they’re linked to a specific evolutionary or cultural question – we spend more of our time painting a broad picture of disease in humankind in the past.

But, to me, the worst misconception is the idea that we have nothing to say to modern practitioners of medicine. Paleopathology is, of course, the study of ancient disease – but we study it so that we can contribute to a better understanding of what’s going on today. Again, it’s about collaboration – we can be useful to clinicians dealing with modern-day health and disease, and they can be useful to us. All we need is communication.

Jane Buikstra is Regents’ Professor of Bioarcheology and Director of the Center for Bioarcheological Research at Arizona State University, USA, and Editor-in-Chief of the International Journal of Paleopathology.