When two young men wading in the Columbia River on a lazy summer day stumbled on a skull and bones a decade ago, the remains looked so fresh that police taped off the area as a possible crime scene. The human skeleton—a scattering of 380 pieces sparked a highly publicized court case that made national headlines for years. A projectile point injury hinted at foul play, but the crime wasn’t murder—this dead man passed away more than nine millennia ago.The rancorous legal fight instead was over whether scientists could study his bones or whether they should be reburied as sacred ancestral remains of today’s native peoples.
Dubbed Kennewick Man, the skeleton quickly became the central figure in the ongoing debate over how to handle ancient human skeletons.After recently winning a nineyear- long legal struggle, scientists are busy analyzing data gleaned from two intensive rounds of laboratory tests. The researchers now believe that Kennewick Man was carefully and respectfully buried on his back after surviving a broken rib, mild arthritis, and a projectile point lodged in his hip before he died of unknown causes roughly around the age of 40.“He led a hard life, but he was very robust,” says Douglas Owsley, a forensic anthropologist with the Smithsonian Institution, who oversaw the tests. A strong right arm suggests that the 5’9” tall Kennewick Man was an able paddler and atlatl thrower.
Kennewick Man, who is housed in the Burke Museum at the University of Washington in Seattle, is the most famous of seven or eight sets of largely intact remains and another 12 or so partial sets that are roughly 9,000 to 11,000 years old and are located across the country. These remains provide Owsley and other scientists the opportunity to apply their increasingly sophisticated techniques to understand how these people lived and where they came from.
The controversy over scientific access to ancient remains started in the 1980s, when Native Americans began to speak out about the callous treatment of the remains of their ancestors in museums and universities, some of which store large quantities of human skeletons. The 1990 Native American Graves Protection and Repatriation Act (NAGPRA) required that skeletons and artifacts be returned to culturally affiliated descendants. But in the case of skeletons as ancient as Kennewick Man, it is far from clear who the descendants are. The courts eventually determined that no link could be made between Kennewick Man and the Umatilla,Yakama, Nez Perce, and Colville tribes who claimed him under NAGPRA.That legal decision gave Owsley and other scientists the opportunity to examine the skeleton in detail in July 2005 and February 2006.
One of the scientists’ first goals was to find out whether in fact Kennewick Man was buried intentionally or whether he drowned or died in the wilderness and was later covered by sediments.He was found on Army Corps of Engineers (COE) land, and therefore they have custody of his remains. The site of his interment can no longer be studied because the COE covered it with rocks to prevent bank erosion. But by examining evidence such as fractures and weathering, as well as indications of the remains being scavenged, forensic scientists can determine if a body was buried by humans or exposed to the elements.
By taking into account these and other factors, the team determined that Kennewick Man was laid to rest some distance from the riverbank, on his back, with his hands at his side, palms down, and feet relaxed. His head was raised slightly, looking toward his feet.“It is a burial,” says Owsley.
His bones had abrasions caused by flowing water.The abrasions were recent, indicating that the water exposed the skeleton not long before it was found. Researchers still don’t know how he died.They do know that it wasn’t due to the projectile point wound, which healed prior to death.
It’s likely that Kennewick Man will undergo further testing, according to Nola Leyde, a spokesperson at the COE’s Seattle office, but no new research proposals have been submitted. She thinks the scientific community is waiting for the reports on the earlier research to be published. In order to be accepted, research proposals have to meet the COE’s requirements.“Our biggest concern is protecting the remains from destruction,” Leyde says. Some tests are more destructive than others. Examining bone or probing teeth for DNA, for example,would require using—and in part destroying— the samples being tested; therefore the COE might refuse such proposals.“At the same time we have a responsibility to assist the scientists,” says Leyde.
Coaxing data from old bones is a complex and challenging task. Bone is a living tissue made up partly of protein collagen within a strong calcium phosphate framework. But variations in temperature and moisture leach out collagen, making a perfectly nice-looking ancient bone worthless to a researcher who wants to extract organic material for radiocarbon dating or DNA testing.The best-preserved burials typically are in tundra environments, dense clay, dry caves, or bogs—places with little variation in temperature or moisture—which can slow collagen leaching.
Techniques for extracting and processing collagen for radiocarbon dating and stable isotope analysis are notoriously varied and susceptible to error. Scientists must consider factors such as possible contamination by modern humans who have handled the material as well as the various collagen purification methods that can produce widely differing results.“Different labs have different procedures to purify collagen,” explains Thomas Stafford, director of Stafford Research Laboratories in Lafayette, Colorado.“ It’s amazing—if you submit a bone to 10 different labs, they will use 10 different chemical procedures.” For Stafford, this chaotic situation is “egregious” because the data can’t be systematically compared for accuracy.
So dating bones remains as much art as science. If an ancient human such as Kennewick Man ate a lot of salmon, for example, then researchers must take into account what’s known as the “marine reservoir effect. ”Coastal fish eat detritus that could be significantly older than the fish themselves. The older carbon is carried from the detritus to the fish to the human eating the fish. Consequently, this marine carbon problem could skew radiocarbon dating of the human remains,making them seem older than they are.This is not an issue for most skeletons found in the North American interior. In the case of Kennewick, researchers estimate the age—adjusted for the marine effect—at approximately 9,400 years.
By combining physical anthropological data with radiocarbon and DNA results, scientists hope to trace the origins and movements of early peoples with a high degree of accuracy. In the 1990s technologies emerged that allow researchers to track mitochondrial DNA, which is passed from mothers to their young, and the Y chromosome that fathers pass to their sons.These genetic changes occur slowly, by mutation, so scientists can tell how much time has elapsed and how closely different populations share particular genetic markers.
But extracting DNA from living people is one thing; finding intact DNA in old bones is quite another. Corpses less than a century old may lack intact DNA. So far researchers have had little success extracting DNA from ancient human remains. In 2000 scientists at three different laboratories tried and failed to extract DNA from Kennewick Man.This effort was part of a battery of tests conducted between 1998 and 2000 by a team of scientists hired by the government to examine Kennewick Man.
David Glenn Smith, a DNA expert at the University of California at Davis, headed one of the teams that tested bone fragments. He wanted to test the teeth, which he thought would yield better results, but that would likely have required slicing open the tooth. Consequently, based on the recommendations of other experts, the COE denied Smith’s request. Researchers were loath to chance destroying evidence. “The problem wasn’t the Corps, it was my own profession,” Smith says.“The best method may be to let this skeleton sit for 10 years and let the DNA technology catch up with us,” Stafford says.
Smith knows of only three successful DNA extractions from remains roughly as old as Kennewick Man: Hourglass Cave, in Colorado;Wizards Beach, in Nevada; and On-Your-Knees-Cave in Alaska. Smith succeeded at isolating DNA from remains found at Horn Shelter, in Texas, that are approximately as old as Kennewick Man, but he couldn’t replicate the results and therefore considered them invalid.“We’ve learned some new tricks to access the DNA when it gets wrapped up in proteins,” he says. That is an improvement over old methods such as diluting a sample to get rid of other material—an approach that itself could destroy the delicate strands of DNA.
The 10,000-year-old remains of a man were found in On-Your-Knees Cave, in Alaska.The DNA, taken from the Ychromosome, was identified as Q-M3, which is found in people living on Siberia’s Chukotka peninsula.This type of DNA is just one mutation away from groups in Central Asia. That particular group has echoes in Europe as well as the Americas.“That may account for the misimpression of European features” among some of the early American bones, says Smith.
Kennewick Man initially made headlines when a cursory examination speculated that his facial features were more akin to Europeans’ than Native Americans.’The explosive implication—that Europeans, rather than the ancestors of today’s Native Americans, settled the New World— set the stage for the bitter clash between the tribes and scientists, most of whom are of European origin.
Owsley’s team used advanced industrial CT scanning to create three-dimensional computerized models from which plastic reproductions of the 11 pieces that make up Kennewick Man’s cranium were created. This was done, at a cost of about $25,000, to create a precise replica of the skull, the formation of which can reveal clues about Kennewick Man’s genetic makeup.
Though researchers examining early American remains insist they do not dispute the old idea that humans moved from Asia to the Americas, they say that the morphological data point to a more varied origin for the likes of Kennewick Man, perhaps from along the east Asian coastline stretching from Japan to Indonesia. Stafford and Owsley back one increasingly popular hypothesis in which small groups trickle along the Pacific Rim coastline, using boats and subsisting in a largely marine environment, over several thousand years.
But DNA results linking the early Americans to living populations will not necessarily help in the quest to pinpoint origins. Populations in Asia continued to move after some split off to head—by boat or by foot—to the Americas.“ Peoples who live in eastern Siberia now may have lived in western Siberia 10,000 years ago,” says Smith. Owsley acknowledges that scientists need to gather multiple lines of evidence of all different kinds in order to paint a more accurate picture of New World settlement.
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KENNEWICK MAN CONCLUSIONS Prior to the recent examinations of Kennewick Man, the National Park Service recruited a different team of scientists to study the remains. This table briefly describes some of the different conclusions the two teams reached. |
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While radiocarbon and DNA testing are central to unraveling the secrets of the early Americans, an understanding of their diets also provides useful information. By analyzing the wear and tear on teeth, for example, the University of New Mexico’s Joseph Powell determined that Wilson-Leonard Woman—who predates Kennewick Man by 1,000 years—had a gritty diet of nuts, wild vegetables and very small animals such as lizards. Before she died around the age of 30, she suffered from an abscessed tooth. “That kind of infection can be deadly,” he adds.
That finding matches that of other bones from the era, including the Horn Shelter remains and a Brazilian skeleton from the same era dubbed Luzia. Powell believes that the early Americans were both hunters and foragers. “In some areas (the Southeast U.S.), they may have done more foraging and hunting of smaller game, while in the Great Plains we have good evidence for large kill/processing sites for megafauna,” Powell says.“The proportions of each must have differed by the environment in which these ancient people lived.”
New technologies may provide a much richer understanding of the lives of ancient humans, though they have yet to be systematically applied. By examining the ratios of two isotopes of strontium found in teeth, 87Sr/86Sr, for example, scientists can surmise the general area, or areas, where an individual resided.The technique is based on the difference of these Sr ratios in marine versus volcanic versus metamorphic rocks, and if an individual migrated from the sea inland towards mountains during the period when his or her permanent teeth became established, the unique strontium isotope signatures of the areas the individual traveled can be seen in his or her teeth.
Mass spectrometers and lasers are used today to examine the isotopes in bone to provide clues to a person’s health, eating habits, and age. But researchers now are using even smaller-scale techniques, known as ion microprobes, on human remains.These instruments can gather detailed data using only minute samples, says Stafford.An ion beam dislodges a molecular fragment from the sample and analyzes its elemental composition.
Owsley says that data gleaned so far from the small set of ancient bones shows that the early Americans had a complicated history of multiple origins.And they had to deal with violence, as indicated by Kennewick Man’s spear point wound, the stab wounds in a skeleton from Nevada’s Grimes Point Shelter, as well as depression fractures to the crania and various bone fractures seen in other remains. Dietary evidence points to a varied lifestyle of foraging. But without the systematic analysis of more ancient remains, the picture of early Americans’ origins and lifestyles remains frustratingly vague.
Owsley is concerned that good data are literally being buried. Native Americans have succeeded in interring some remains that are 9,000 to 11,000 years old.The remains did undergo some scientific tests prior to reburial. The partial skeleton of a woman discovered in 1989 who lived more than a thousand years before Kennewick Man in Buhl, Idaho, was reburied in 1991 following radiocarbon dating, teeth casts, and isotopic analyses.Two skeletons approximately 8,500 and 10,000 years old were reburied in Minnesota after a brief examination.
Others skeletons lie in legal limbo. Spirit Cave Man, a skeleton discovered in a Nevada cave in 1940, was wrapped in matting and a rabbit-fur robe and is remarkably intact. He still has all his teeth, though three abscesses and a severe cranial fracture hint at a physically punishing life. Morphological data indicate that Spirit Cave Man bears no close resemblance to modern populations; however, he does bear some resemblance to the Ainu, the aboriginal people of Japan.The bones are now the subject of a legal battle, with Nevada tribes lobbying for their return and reburial, and DNA testing is now prohibited.
But there is a chance that in coming years new methods such as ion microprobes may provide a compromise between scientists and Native Americans.“We can get a lot out of these skeletons and not destroy them,” says Stafford. “We can show that it is possible to be respectful while conducting detailed analyses.”Adds Powell:“We’ve gone from using huge amounts of bone to tiny samples—in another 40 to 50 years,we may not have to destroy anything at all.” That may get the early Americans out of court and into the lab—but with all the respect due to our elders.