Sunday, November 04, 2007

Long ago and far away

According to a story in Science, the National Museums of Kenya will lend the fossil bones known as the Nariokotome Boy to the Field Museum in Chicago for a paleological exhibit. The 1.5 million-year-old fossils are the most complete skeleton of Homo erectus ever found, after Lucy perhaps the most famous fossils ever. The name comes from the place in Kenya where the bones were found. Many paleoanthropologists are aghast that these fragile and precious specimens will be put at risk by travel and display, including Richard Leakey, whose team discovered the partial skeleton in 1984.

About a decade after the discovery, I was sent a life-sized poster of the fossil skeleton by Harvard University Press, to promote a book, The Nariokotome Homo erectus Skeleton, edited by Alan Walker and Richard Leakey. For a long time, the poster boy hung on the wall by my desk. I grew quite fond of him. I called him Nari.

According to the experts, he was in life 11 or 12 years old, a strapping youth of about 5-foot-3. He would have stood over 6 feet tall had he lived to maturity. To my untutored eye, the skeleton looked remarkably modern. The proportions of the body are graceful, almost delicate. I needed only to close my eyes and the fleshed-out boy stepped forward from the wall, grinning good-naturedly, hand extended in greeting.

Nari lived in rich grasslands bordering a river that flowed near what is the present basin of Lake Turkana. The river's seasonal flood left several large swamps that would take most of the year to dry out. The grasslands and swamps were home to many species of plant-eating animals, together with their attendant predators and scavengers. Volcanoes occasionally showered the river valley with blankets of ash. All of this can be discerned from the fossil and geological evidence.

How did Nari die? His skeleton shows no signs of violence. The only abnormal feature is a pocket of inflammatory gum disease related to the loss of a tooth not long before his death. Before the advent of antibiotics half a century ago, death from septicemia from tooth and gum abscesses was common. Nari may have died from gum infection after the shedding of a milk tooth.

At death, his body either fell into a swamp or was washed into it by a minor flood. For a while it floated face down while decomposing. The body drifted a few meters, was trod upon by hippos, sucked by catfish and chewed by turtles. In time, nearly all of the bones came to rest in a shallow part of the swamp, became embedded in mud, and remained there for a million-and-a-half years until they began to be eroded out of sediments at the side of a small tributary of the Nariokotome River.

In life, Nari was powerfully muscled, yet slender -- a runner's build. He was at the age when he was learning the arts of hunting and gathering from his elders. Like them, he almost certainly prepared his prey for eating with carefully-crafted stone choppers and scrapers. He may have used fire.

All of this marks Nari as a true human ancestor. But there is so much more we want to know, about which the bones are silent. Did he speak? Did he fall in love? Did he grieve for a dead friend? Did he dream?

The authors of The Nariokotome Homo erectus Skeleton struggled with these questions, most explicitly the first. They measured the bones in every possible way, comparing them with modern skeletons. They examined the shape and size of the brain case, looking for clues to those parts of the brain known to be crucial for speech. They examined the air passageways of the nose and throat. They probed the spinal cord for clues to the central nervous system. Four-hundred pages of graphs, charts, schematics, measurements, and comparisons. In the end, the bones retain their most precious secret: Nari's inner life.

What was he thinking as he lay at the edge of the swamp, racked by the pain of infection, burning with fever? Did he know that he was going to die? Did he grieve for the life he would not live? Did he cry out at the unfairness of a universe that would take a boy in the prime of his life?

If a skull can be said to have an expression, there seems to be a fierceness to Nari's face, perhaps even anger. Did he rage, rage against the dying of the light with a fully human consciousness? Or was he silent, thoughtless, not yet capable of having or of giving expression to thoughts of the terrible and the sublime?

I can't tell you why, but looking at Nari's skeleton, I knew that he was me -- my bone, my blood, my incipient dreams, rooted deep, deep in the evolving mystery of consciousness, long ago and far away.

Further Reading

If you have $260, here is the book: The Nariokotome Homo erectus Skeleton

Discuss this essay and more over on the Science Musings Blog.