ANCIENT SKELETONS COULD GIVE US CLUES TO MODERN DISEASES
Scientists
say studying the bones of the Mississippians may be as important
to understanding our time as it is to understanding theirs.
By William Allen
and John G. Carlton
Of the Post-Dispatch
Dec, 26, 1999
Edited by Virginia Baldwin Gilbert
The life stories of the Cahokians are written in their bones.
These stories aren't recorded in hieroglyphics or some other ancient language, but rather in the marks of disease and malnutrition left in skeletons.
Scientists who can read this alphabet of injury have added insight into the health and diet of the people who lived in the St. Louis region a millennium ago.
What they've found may be as important to understanding diseases today as it is to understanding life when Cahokia was the center of a great prehistoric civilization. This knowledge of disease behavior could benefit the health of current and future generations, researchers say.
"If we can reconstruct the past, we can get a better feel for how diseases alter bones and how illnesses influenced the lives of ancient people," said George Milner, an archaeologist and osteologist, or bone specialist, at Pennsylvania State University in State College, Pa.
"We know that diseases and their human hosts are not static -- the relationship between them continues to evolve," Milner said last week. "What we want to do is get more information about how diseases evolve over a very long period of time."
The constantly changing relationships between humans and disease organisms is perhaps best exemplified today by AIDS.
"It's one of a long string of new introductions of disease to human populations, often with catastrophic consequences," Milner said.
Another prominent example is the Black Death, the bubonic plague that devastated Europe and Asia in the 1300s and 1400s.
Milner has led investigations of Native American bones in the St. Louis region and elsewhere.
Put simply, Cahokia residents were much like other late prehistoric Indian populations in the eastern woodlands, Milner concluded.
They suffered nutritional problems, such as iron-deficiency anemia. This resulted from a lack of iron in the diet, an infectious disease or both. Some also may have had scurvy, a lack of vitamin C. Both deficiencies cause weakness and other conditions, including vulnerability to infectious diseases.
Among several infectious diseases they confronted were two that are similar to modern tuberculosis and yaws, both of which can damage bones.
Scientists reach such conclusions after careful examination of hundreds of skeletons unearthed in archaeological digs. Examples of clues written in the body include:
* Pits or horizontal grooves in the teeth. These indicate that the person, when young, experienced a period of severe malnutrition or a bout with an infectious disease. Such features are common today in poor countries.
* Thicker-than-usual bone in parts of the skull. For example, iron-deficiency anemia can produce thicker, rougher bone in the brain case and the plate of the bone above the eyeballs.
* A hunched back from destruction of the lower backbone. This is a common feature in untreated tuberculosis.
* Injury to parts of the skull and tibia, a lower leg bone. A sign of infection by bacteria that cause yaws and related diseases.
On average, Cahokia residents had fewer injuries from disease and malnutrition on their skeletons than Indians elsewhere in eastern North America.
Why?
"It could be that compared with others, these people were pretty well off living in the Mississippi Valley, a very rich environment with a more plentiful and regular source of food," he said. "But that is sheer speculation."
Despite these advantages, the health and nutrition of Cahokians was far from that of residents today.
"Even though they lived much better than many others then, they still had a limited capacity to produce, store and transport food," Milner said. "And it wasn't like today, where you can go to a local grocery store and buy fruit from California."
Environmental disasters could occur at any time. Floods and drought could bring lean years, limiting crops and causing famine.
Living in large communities may have led to soil, water and food contamination. That might have allowed diseases to spread more easily.