Ten years ago, two young men encountered a human skull in the Columbia River at Kennewick, Washington - which was subsequently labeled "Kennewick Man."
Now it appears that analysis of Kennewick Man, places him "closer to southern Asians and nearly equidistant to modern Native Americans and Polynesians."
That's because the skull "appears to have strongest morphological affinities with populations in southern Asia, and not with American Indians or Europeans in the reference samples" according to one study.
The interpretations by anthropologists Joseph F. Powell and Jerome C. Rose are based on a scientific technique called craniofacial morphometric analysis. It involves detailed study of the shape of the skull and face, using a sophisticated method called multivariate analysis. In some cases, more than 60 different dimensions of a skull are measured and compared with comparable dimensions considered typical of specific racial groups.
Anthropologists have established a range of measurements considered characteristic of the majority of members in each major group, even though most anthropologists agree that races, as most people use the term, are socially defined groupings with no scientific definition. No physical traits are exclusively the property of one race or another. Still, anthropologists agree that certain combinations of measurements, chiefly of the face and skull, can be used to determine whether individuals belong to one population or another. This is true primarily for groups that have been separated geographically for thousands of years.
All of which raises unsettling questions about the origins of the first Americans. Were they all from Asia? And are they actually direct descendants from people of South Asian origin?
Early descriptions of the Kennewick skull led to reports that the man was Caucasoid and possibly European. After a more careful analysis, the skull appeared to be longer and narrower than those of Native Americans. Dr. Joseph Powell of the University of New Mexico reports that its physical affinities appeared to be closer to those of South Asians or Polynesians than either Europeans or American Indians.
The case has become so inflamed that scholars involved speak of shouting matches and threatened fisticuffs at academic conferences, as well as vindictive silent treatments meted out in divided university anthropology departments. Debate about race has deepened the resentments.
The conversion of a 9,000-year-old skeleton into a racialized proxy for conflicts about American culture and identity provoked angry interventions by yet more scholars. They saw no convincing evidence of European origin. All the talk about Kennewick Man's identity, they argued, dangerously misconstrued the meaning of race.
("Caucasoid" is a term used by physical anthropologists to describe skull and skeletal shapes common today in Europe, the Middle East and South Asia, and does not typically refer to skin color. However, the word "Caucasian," which is often used by Americans to refer to whites, is defined in Webster's as a synonym of "Caucasoid." Thus even when scientists believe they are using a technical, race-neutral term, they can be understood as referring directly to race.)
Until very recently, nearly all scientists taught a confident, consensus narrative about how the continent was first populated. As the Ice Age ended about 12,000 years ago, they said, Asian mammoth hunters migrated from Siberia across a land bridge that stretched to modern Alaska. The migrants then headed south through an ice-free corridor that led to today's Montana. From there the hunters spread out and propagated. This was always a questionable theory, more securely grounded in facts about prehistoric geology than in hard evidence about human movements. Yet the story was often taught in American schools as if it were certain.
No more. Kennewick Man surfaced just as new discoveries were encouraging radical revisions of old theory. Evidence of late Ice Age human settlements on California's channel islands, in Chile and elsewhere suggests that humans may have first moved around the Americas by boat, and may have arrived much earlier than previously believed. If a current consensus can be said to exist, it describes multiple migrations from multiple Asian origins by multiple means over thousands of years -- certainly not a single march across the land bridge.
Dr. Douglas Owsley of the Smithsonian Institution and Dr. Richard Jantz of the University of Tennessee at Knoxville reported that close examination of the craniums of several other skeletons and mummies found in the Americas produced similar results. The evidence, they said, suggested that either more than one group of people migrated into the New World or the settlers underwent significant physical changes in the time after their arrival. It is even possible that the first migrants became extinct, replaced by subsequent groups. And when Owsley and Jantz examined some of the oldest North American remains, the skulls didn't provide the kinship clues they expected. "They do not have the broad faces, they do not have the big, prominent cheekbones that you think of as the more traditional features of the Chinese and American Indians." Instead they looked more like the inhabitants of, say, Indonesia, or even Europe.
Owsley and Jantz weren't the first to notice this discrepancy. In the early 1990s anthropologists Gentry Steele of Texas A&M University and Joseph Powell of the University of New Mexico at Albuquerque had collected craniometric data from four North American skulls between 8,000 and 9,700 years old. They found the same puzzling differences between those subjects and modern Native Americans, and the same puzzling affinities with South Asians.
A survey of prehistoric South Americans by anthropologist Dr. Walter Neves of the University of Sao Paolo yielded similar findings. Neves has suggested that some of the first people in South America might have originated in Australia, or at least South Asia. They may have come across the Pacific, but more probably, he said, they were a branch of Southeast Asians, some of whom settled in Australia as the Aborigines while others navigated northward along the Asian coast and then across the Bering Strait.
Then Kennewick Man appeared in an eroded bank of the Columbia River. And last year Neves reported that the oldest American, an 11,500-year-old skeleton from central Brazil, also shares the appearance of South Asians.
What this means is that American prehistory has been plunged into a new period of tumult and uncertainty over its oldest mystery, one critical to understanding how modern humans spread out through the world. For their entry into America was the last time in history when people occupied an entirely new land, alone and with little more than their own ingenuity and an eye on far horizons.
''We're going to have to open our minds,'' Dr. Michael B. Collins of the University of Texas said at a conference. ''We're going to have to explore some ideas that may not get us very far. We're going to have to be tolerant of each other as we explore these ideas. My God, this is an exciting time to be involved in research in the peopling of America and the earliest cultures of the Americas.''