Researchers in fields from epidemiology to genetics are studying mummies, using the latest imaging technology. Now we know more than ever before about what lies beneath the mummies' wrappings — and these long-dead people are telling us a lot about ancient lives and cultures.
Just like modern hospital patients, mummies are subjected to high-tech tests and scans. X-ray, magnetic resonance imaging (MRI), and computed tomography (CT) scans let researchers study the anatomy of mummies in 3D detail without having to damage the remains with a physical autopsy. This keeps the bodies intact, which is good for science — and can be more respectful of ancient cultural traditions, too. Terahertz imaging, the same technique used at airport security checkpoints, is useful for looking at hidden objects like amulets tucked into a mummy's burial garments. Researchers can even take biopsies, or small samples of tissues, to get a closer look inside a mummy's organs.
CT scan of the mummy in the top image. Credit: U.S. Naval Hospital, San Diego.
What Pollen Can Reveal
Studying mummies can yield surprisingly personal glimpses into how people lived and died in the past. For instance, archaeologists used CT scanning and microscopic analysis of pollen to examine the mummified remains of an elderly Korean general who died in the 16th or 17th century.
In the CT images, they found coprolites — preserved faeces — in the general's large intestine. (There is little dignity in death, especially if your corpse is historically significant.) Researchers were interested in the coprolites because they wanted to know what the general had eaten in his final days. In particular, they were interested in what kinds of pollen the coprolites contained.
The colon of the mummified general. Picture: Annals of Anatomy
Depending on how food is prepared, traces of pollen may get ingested along with fruits, vegetables, spices, or teas. Pollen can linger in the digestive tract for up to three weeks — and if you die and then get mummified, that three weeks can stretch into thousands of years. In forensic terms, pollen is the epitome of trace evidence. Pollen grains are tiny and easy to overlook, but they can reveal a lot of information about what the deceased ate and drank, what medicines (or recreational drugs) he took, and even when he died.
So researchers used chemical techniques to extract pollen from the general's last bowel movement and then examined the grains under a microscope. His coprolites contained lots of pollen from aquatic plants, but not as much as they would expect to find if he had just been eating the plants; instead, the pollen seemed to have been in the water. That says something about the general's water sources, but it also means that he probably drank a lot of tea and broth in the days before his death. Analysis also uncovered pollen from a species of sage often used as a medicine for abdominal pain, so it's easy to imagine that the general wasn't feeling well — although his death appears to have been due to injury, not illness.
However, it seems that the general wasn't entirely on a liquid diet in his last days. Remains of buckwheat pollen, along with pollen from the mustard family — which includes bok choy, broccoli, cabbage, cauliflower, cress, and mustard — give us a picture of what he typically ate. And based on the seasonal availability of those plants (because there wasn't much of an off-season market in the 1600s) it seems that the general died during the winter, between November and February.
Tracing Modern Maladies
Mummification doesn't just preserve tissue. It can also preserve ancient DNA, and scientists have the tools to extract it, sequence it, and study it. In fact, some remains are so well preserved that scientists can extract the DNA of ancient bacteria, viruses, and parasites to learn about diseases in the past.
It's a challenging process, and researchers have to be careful not to contaminate the remains with modern germs during excavation and lab work. Over the last two decades, however, they have been pretty successful. Diseases that have been buried with mummies around the world include Spanish flu, leprosy, Hepatatis B, and the protozoa that causes malaria.
Some of the first researchers to sequence DNA from an ancient pathogen were the scientists who extracted Mycobacteria tuberculosis bacteria DNA from a 1000-year-old Peruvian mummy. They shared their results in a 1994 paper. Other researchers studied the DNA of tuberculosis in scores of Egyptian mummies, and they have tracked changes in the disease's genome over the 3000 years of ancient Egypt's history. Their work gave us a better idea of where tuberculosis came from — and how it changes over time.
Knowing the evolutionary history of a disease helps modern epidemiologists predict how the disease might evolve during modern outbreaks. It can also reveal how the disease is related to other pathogens, pointing doctors toward potential treatments or vaccines.
Mycobacteria tuberculusis. Picture: National Institutes of Health
It also helps to know how common a disease was in an ancient population, how quickly it spread, and which groups of people were most vulnerable. Today, modern antimicrobial medicines can cover up other factors — like environment or diet — that could make people more or less susceptible to a pathogen. Learning how that pathogen behaved in a world before antimicrobials can help doctors better understand how it spreads and how to control it.
We've used today's most sophisticated imaging and DNA sequencing technologies to to learn about the more humble parts of our ancestors' lives. Archaeology revealed their monumental architecture and offerings to the gods. But only modern technology allowed us to learn what they ate and what ailed them.