SCIENCE

Reading the Bones

August 2000

On a table in a nondescript room in the National Museum of Natural History lies a set of disarticulated bones arranged in a familiar pattern. But the resemblance to a human skeleton is not quite complete. The bones have been broken and reassembled, and weathered by time and exposure to soil. Douglas Owsley, a forensic anthropologist at the museum, points to a sign of imperfection in one knee joint and says the man was shot.

The skeleton is from an early-17th-century grave in Jamestown, Virginia, and the shooting took place centuries ago. But as Owsley speaks of the injury to the bones, the centuries fall away, and the listener's imagination goes to work. The skeleton is no longer an anonymous disposition of collagen, calcium and phosphorus, but a person, of a certain age and physical stature and medical history.

When Owsley and his colleagues look at bones, they see changes in texture and form that are evidence of disease. They see variations in size and shape that tell of age, sex, musculature, handedness and repetitive lifetime activities. Molecular and biochemical analyses of bone samples can yield DNA and dietary information, and sometimes isolate antibodies that enrich our understanding of the incidence and transmission of disease in the past.

The bones can record aspects of an individual life or of a community; they can reveal customs and conflicts. Sometimes they can preserve information about evolutionary history. For example, the study of skeletal remains, in conjunction with new archaeological discoveries, may challenge the history of the original colonization of the Americas. The long-held theory that all New World native peoples are the direct descendants of a small band of big-game hunters who came to the Americas some 11,500 years ago may no longer suffice. Skeletal evidence from North and South America dating back at least 10,000 years indicates that the New World may have been colonized on numerous different occasions, beginning thousands of years earlier than previously thought, and that the colonizing groups may have come from different regions in the Old World.

Because of their skill at piecing together lives from skeletal clues, forensic anthropologists have been enlisted as allies by law enforcement and public health agencies to help identify victims of accidental or intentional death. In fact, the tradition of forensic anthropology at our Natural History Museum goes back half a century. The scientific skills honed on evidence centuries and even millennia old, from which time and distance have drained emotion, can be invaluable in grim contemporary circumstances that are often charged with live and painful emotions.

Smithsonian scientists have been involved in identifying victims of serial killer Jeffrey Dahmer, of the fire in the Branch Davidian compound and of war in Croatia. In the Dahmer case, our scientists were able to make a positive identification of his first victim, though the fragmented and incomplete remains had been exposed to the elements for many years. The anthropologists succeeded because they were able to match osteological features evident in antemortem and postmortem x-rays of a cervical vertebra of the victim. Such work has built a portfolio of case studies that advances the field of forensic anthropology and helps develop the skills of a new generation of investigators.

Not every case is so notorious, of course, but in every one the final disposition of one or more human lives is at stake. That's one reason Doug Owsley thinks of the forensic work as a public service. It may lead to the punishment of individuals who have engaged in violently destructive acts. But it is also work of humane consequence for the living. Most victims have families, relatives and friends whose lives have been shattered by loss and uncertainty. The skill of the forensic anthropologist cannot lessen the anguish of loss, but it can lessen the anguish of doubt. In so doing, it serves science, justice and humanity.