19 February 2006
Researcher seeks secrets of Kennewick Man
Ground to the bone, the teeth of the famous fossil skeleton, Kennewick Man, look as if they've spent a lifetime gnashing rocks. But it's from these worn choppers that Thomas Stafford Jr., a research fellow in the department of geology at the University of Wisconsin-Madison, plans to learn about the origins, movement and lifestyle of this highly controversial, 9,000-year-old North American.
In 1996, Kennewick Man was discovered on the banks of the Columbia River near Kennewick, Wash. Kennewick Man's discovery and description excited and rattled not only scientists but also American Indians and government officials.
And for the past nine years, his bones have been locked away as court battles have ensued over his future. In February 2004, the U.S. Court of Appeals ruled in favor of the scientists. And last summer, for the first time, scientists began investigating this enigmatic American.
Stafford has begun examining Kennewick Man's teeth. He's working with John Valley, a University of Wisconsin geologist, to decipher the secrets hidden in the worn enamel of this enigmatic fossil. From the fossil's tooth enamel, they'll learn where Kennewick Man lived as a child, the kinds of food he ate, from where and whence he traveled, and when he died. Although enamel is an extremely hard substance, it's actually more like a sponge in terms of its record-keeping - soaking up and recording the events of an individual's early life.
For starters, Stafford is going to try and figure out when Kennewick Man died. While most experts agree his death was likely 8,000 or 9,000 years ago, the five different dates collected so far have varied by as much as 3,000 years.
To settle the issue, Stafford will use radiocarbon gleaned from Kennewick Man's teeth to give a definitive answer. But Stafford's hoping that Kennewick Man's teeth can tell him more than when he died. He's working with Valley try to figure out what kind of climate Kennewick Man was born in.
They will analyze the ratio of a heavy form of oxygen (Oxygen 18) to a lighter form (Oxygen 16) stored within them. Stafford and Valley are interested in oxygen because water - local springs, lakes and rivers - contains isotope signatures that are particular to geographic regions. These signatures become embedded in the enamel of a person's teeth. And because enamel is laid down early in life - depending on the tooth, it can accumulate anywhere between birth and adolescence - researchers can gain information about the birthplace of an individual, and possibly whether he or she migrated or moved as a child. Therefore, Kennewick Man's teeth "should tell us about the temperature," of his environment "and the source of water this individual was ingesting," said Valley, as well as whether he grew up in a lower or higher latitude, close to the sea or far inland, high on a mountain or deep in a valley. In other words, they should be able to say whether Kennewick Man was a Kennewick native, or not.
That's a key question. Did Kennewick Man grow up elsewhere and trek across the Bering Land Bridge to present-day Washington state? Or was he born there - representing an, until now, unrecognized population? "We don't really know what happened," in terms of the populating of North America, said Stafford. "It's possible there were several waves of migrants moving into the continent." Some, like those in Kennewick Man's population, may have died out. They may have been killed. Or they may have interbred with other groups who were already here or yet to come.
Stafford, who was not part of the original team of scientists who fought to study Kennewick Man, said that all of his work has been done in conjunction with the core group of researchers, including Doug Owsley at the Smithsonian Institute; James Chatters, the archaeologist who first excavated Kennewick Man; Vance Holliday, an archaeologist at the University of Arizona; and others.
The team will be presenting some of its preliminary discoveries later this month at the annual meeting of the American Academy of Forensic Scientists in Seattle.
Source: The State.com (6 February 2006)