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| Vol. 17, No. 39 | Aug. 20, 1998 |
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| Vol. 17, No. 39 | Aug. 20, 1998 |
When the skeletal remains of an unknown person are discovered sometimes years after the time of death, the police and Medical Examiner's Office call upon UD physical anthropologist Karen Rosenberg for assistance.
As a physical anthropologist, with expertise in anatomy and skeletal structure, Rosenberg can determine several characteristics about a person from examining their bones, and using her skills as a forensic scientist comes with her profession.
"When bones or a full skeleton are discovered in remote woods or in a river with no way of identifying the person, that's when they call on me," she said. "If there is soft tissue, clothing or other identification, it is much easier to characterize a person and eventually possibly identify him or her. But if they find just bones, they call a physical anthropologist because we are trained to interpret skeletal remains."
If it is not a full skeleton, the first thing she determines is whether the bones are animal or human, she said.
"By gross examination, I can determine the height, age and sex of the person. The police authorities always ask for the race of an unidentified person. But racial categories are, in part, culturally defined and in any case are not closed biological 'types.' Recently I identified a skeleton as possibly being Caucasian, then on subsequent examinations thought he might be African American. In actuality, when the identification was made, he turned out to be Hispanic," she said
In a case reported in the News Journal, bones were discovered by a hunter in Kent County woods. When it was determined that the bones were human, the police excavated the site and found the skeleton of a person whose skull had been bashed by a blunt object. Rosenberg helped the police determine that the bones were those of a medium-sized woman, probably white, more than 40 years old with signs of arthritis. The body had probably been there for a few years.
"I usually do not hear back whether they have identified the person although I did receive a letter from the Medical Examiner's Office saying I was right on target with an analysis. The people whose remains are found long after death are frequently on the fringes of society-their parents are not necessarily out there looking for them-and are not reported missing. Many have had little or no dental work which makes identification more difficult," she said.
Rosenberg's relationship with the Medical Examiner's Office began when she was conducting research in the late 1980s at the Island Field Site, a burial site of Native Americans in Kent County. The skeletal remains of 140 Native Americans, approximately 1,000 years old had been discovered there.
Research at the Island Field Site was an opportunity for a team of scientists to learn about the Native Americans themselves and their lives--analyzing their height, their diet, dental decay and wear, nutrition and disease, among other factors, she said.
"After analysis, the remains were reburied at the site, and the medical examiner was involved in the committee overseeing the project. I was asked if I would assist them in cases involving skeletal remains, as my predecessor at UD had done, and I have been called upon two or three times a year since then," Rosenberg said.
Rosenberg's main area of research is in paleoanthropology in how and why evolutionary change occurred in humans. She has traveled around the world studying fossil remains of ancient peoples, focusing mostly on Neanderthals, who lived in Europe and the Near East 100,000 years ago, and their contemporaries from other regions.
Most of her work has been done on fossil remains in museums, and her research has taken her to many European countries, Japan and Israel. Most recently, she has visited China twice, working with a Chinese anthropologist at Beijing University who discovered the fossil remains of a woman who had lived approximately 280,000 years ago.
Rosenberg's field is human evolution and the origin of modern humans. "Paleoanthropologists are interested in how people lived in the evolutionary past and how environmental and cultural conditions affected the evolutionary process. We want to understand which fossil humans were our ancestors and how and why evolutionary changes occur," she said.
Most recently, Rosenberg's research has focused on the evolution of the human female pelvis and human childbirth. It is generally understood that major factors in the evolution of the human female pelvis are that humans walk upright and that human babies are born with big brains, which have to pass through the birth canal during childbirth. For centuries, childbirth was a leading cause of death among women and a certain natural selection probably took place, she said. Today childbirth is difficult, but mortality is reduced because of medical intervention.
In a recent paper in Evolutionary Anthropology, which she wrote with Wenda Trevathan of New Mexico State University, Rosenberg compares the birth canal and the birth process of humans and other primates. Unlike humans, other primates seek seclusion when giving birth, away from predators, and it is a solitary event. Because the infant non-human primate emerges from the birth canal facing the front of the mother, she can assist at the birth.
The human infant, on the other hand, emerges facing away from the mother, which hinders her from assisting at the birth. As Rosenberg and Trevathan point out in the article, "The presence of another individual who can assist in the final stage of delivery reduces the risk of mortality for the infant and probably the mother as well...the desire for supportive, familiar people at birth is deeply rooted in human evolutionary history."
Rosenberg is currently involved in planning an interdisciplinary conference on childbirth and in writing more on this topic.
A graduate of the University of Chicago with a degree in cultural anthropology, Rosenberg received her doctorate in biological anthropology from the University of Michigan and came to UD in 1987.
--Sue Swyers Moncure
