WASHINGTON - Under hot floodlights, a man in a white lab coat gently lifts a loose end of the mummy's fragile linen bandage and begins to unwrap the preserved corpse. Brown dust, undisturbed for more than 2,000 years and pungent with ancient Egyptian balms, swirls into the nostrils of a dozen scientists bent over the small human form lying on a wooden table.
Slowly, the researchers peel back about 20 layers of ribbonlike bandage. After nearly six hours, they expose the dried body of a woman, perhaps 25 years old, who died 2,000 and 2,300 years ago. Though severely shrunken, many details of the body's surface - fingerprints, hair - are evident.
Thus, in a laboratory at Wayne State University in Detroit in the 1970s, did the members of what was then a fledgling organization - the Paleopathology Association - open a new chapter in the scientific effort to learn about human diseases in ancient times.
Curiosity about humanity's past had long driven historians and archaeologists, but this group had a more specific interest - the physical health of people who lived in long vanished times.
Did people have cancer and heart disease thousands of years ago? Were they well nourished? What kinds of infections did they have? Have diseases changed along with human culture? Is it true that the health of people today generally is better than that of the ancients?
Such are the questions that paleopathologists try to answer, primarily by studying the bodily remains of people who died long ago. The better preserved the corpses, the better the chance of finding signs of ancient pathology.
Ancient human remains have revealed signs of many diseases. In fact, according to Donald Ortner, a Smithsonian Institution paleopathologist, virtually all modern diseases that leave clues on the bones have been found in ancient skeletons. His examination of bones buried in a 5,000-year-old Jordanian town revealed, for example, that a child, 7, and a man, 18, had tuberculosis, which leaves telltale pits on the spine.
Along with tooth decay, probably the most common disease found on old skeletons is arthritis, which has been diagnosed in the bones of Neanderthal people who lived more than 35,000 years ago. Arthritis has been found in virtually every skeletal population examined.
Tooth decay is at least as old. In fact, periodontal disease, often described by dentists as the most common oral ailment of today's adults, has been diagnosed in a prehuman hominid - a 3 million-year-old Australopithecus child. Bone cancer has been found in a variety of places and past times. Trachoma, an eye disease, has been seen in a prehistoric Australian aborigine.
One of the most startling discoveries of ancient disease has yielded broader insight into human nature. In a Florida bog near Cape Canaveral, anthropologists have found the skeleton of a child who had spine bifida, a serious birth defect in which the spine fails to close over part of the spinal cord.
The victim was a boy of 16. Worse, the boy was doubly handicapped. His right shin bone ended in a gnarled knot, presumably all that was left after his foot withered away. Because such a bone deformity would have developed over years, anthropologists speculate that the boy was severely crippled for a long time before death, He lived 8,000 years ago, and his remains were formally buried in the bog.
"This clearly was a culture that could care for a person with a pretty serious handicap," says Glen Doran, a Florida State University anthropologist involved with the dig. "It's not the way you usually think of prehistoric hunter-gatherers."
An even older discovery offers a similar example. The earliest known example of dwarfism was found in an 11,500-year-old skeleton of a boy, 17, unearthed in Italy. The boy, who stood only 1 meter tall, had been ritually buried, indicating that despite his handicap - or perhaps because of it - he was regarded as a full-fledged member of his society. He lived at a time when humans were beginning to make the transition from hunting and gathering to primitive farming.
'Progress' vs. disease
While isolated findings such as these often make news and can shed light on the antiquity of various diseases, paleopathology also has yielded broader conclusions about the origin and evolution of disease. For one thing, it now appears that some of the most epochal examples of "progress" in human culture have been bad for human health.
The culprits were the replacement of the hunting-and-gathering lifestyle with that of agriculture and the ensuing rise of what anthropologists call sedentism - living in permanent settlements instead of wandering. Especially bad have been settlements that grew into cities.
These developments have led to such important advances in human society as the rise of education, the arts, the sciences, modern technology and many other things that fall under the term "civilization." But those gains came at a cost to the level of health enjoyed by people who practiced the original way of human life - nomadic hunting and gathering.
The price has been an increase in the prevalence of certain diseases, an increase not overcome until well within this century and then only in more affluent countries. The high prevalence of infectious diseases and malnutrition in urban areas of today's Third World, medical archaeologists have found, reflects not the natural condition of the original human way of life but the persistence of miseries exacerbated by agriculture and civilization.
Only within the lifetime of many people now living have these ills been banished in the industrialized world through provision of safe drinking water, sewage treatment, reliable food refrigeration, safely canned foods, antibiotics and vaccines.
Scourge of sedentism
Until about 12,000 years ago, all people lived in societies that depended on hunting or fishing for meat and gathering wild plants for fruits and vegetables. They lived in small bands that moved from place to place, sampling the resources of many regions as the seasons changed.
If today's hunter-gatherers are any clue, the diet was highly varied, typically drawing on scores of plant and animal species. The menu was low in fat, high in fiber, rich in vitamins. Good food was easy to find and cheap. Because human population density was low, people met outsiders only rarely and thus were seldom exposed to contagious diseases. Also, by traveling long distances on foot, people got plenty of exercise and fresh air.
That sounds like a healthful way to live, and in recent years, paleopathologists have found evidence that it indeed was.
Some of the best evidence of life before agriculture comes from work by Douglas Ubelaker of the Smithsonian Institution's National Museum of Natural History on a remarkable burying ground in Ecuador that contains about 200 skeletons of people who lived about 8,000 years ago.
Samples of burial remains from throughout the group's existence and from still-later eras indicate that the spread of disease became worse.
"If you compare over the whole time span," Ubelaker says, "there's no question that, at least from what we can see in the bones and the other remains, the health of these people has gotten progressively worse. No matter how you look at it - infant mortality, tooth decay, anemia, infectious disease - it all went downhill with agriculture and sedentism."
For example, incidence of tooth decay went from 3 percent of teeth in hunter-gatherer times to 8.7 percent after the arrival of agriculture 4,000 years ago and to 17 percent once Ecuadorians were living m farm-fed cities.
With the rise of European-style cities, the variety of food dwindled to corn, potatoes and manioc - all high in decay-promoting carbohydrates.