The village of Herto, in the Middle Awash region of Ethiopia, is surrounded by sparse patches of dry, scrubby vegetation, barely enough to sustain the sheep, cattle and goat herds of the seminomadic Afar people who live there. But 160,000 years ago, conditions were far different: a shallow lake sat here, teeming with hippos, crocodiles and catfish. The lush grasslands that surrounded its pebble-strewn shores were filled with lions, zebras and antelopes as well as another creature, which traveled on two legs rather than four. Our distant ancestors had walked the earth for millions of years by this time, and although they stood upright, many looked more like apes than like us.
These hominids were different. Properly dressed, they could walk down New York City's Fifth Avenue without attracting a second glance. Many of the hallmarks of modern humanity, including art, culture, spoken language and civilization, were probably still tens of thousands of years in the future. But for the first time in history, evolution had produced creatures that looked like us and--at least in some ways--acted like us as well.
Until now, paleontologists could only speculate about the existence of such people. But an international research team co-directed by Tim White of the University of California, Berkeley, reported in Nature last week that it has finally unearthed the long-sought fossil remains of what could be the very first true Homo sapiens, dated to between 160,000 and 154,000 years ago. And because of the quality of the specimens and where they were discovered, they cast new light on several of paleontology's thorniest questions.
The discovery was largely an accident, one that never would have happened if not for El Nino. Back in 1997, the Pacific Ocean disturbance that affects much of the world's weather triggered punishing rains in Ethiopia. The deluges not only exposed buried fossils but also drove away the people of Herto and their livestock, which would have trampled the fragile bones. When White and the others happened to drive by the village, they noticed a fossil hippo skull poking out of the ancient sand. On closer examination, the skull bore marks indicating that the animal had been gashed with a stone tool. Clearly, human ancestors had once lived there.
When the scientists returned 11 days later, it took them only minutes to find the skulls of two adults, probably male. Six days after that, Berhane Asfaw of Ethiopia's Rift Valley Research Service found a third, the skull of a 6-or 7-year-old child, shattered into about 200 pieces. After years of painstaking cleaning, reassembly and study, the team was confident enough to tell the world that it had found the earliest true Homo sapiens--older by at least 1,000 generations than anything previously discovered. "It's not a modern human," says White, "but it's so close that there's no doubt it will become one. The child, in particular, is so like us that you couldn't distinguish it in a population of modern human children."