National Geographic : 2010 Jul
• literally walk from one to another in the course of a couple of days. He invited me to join the team in the eld so they could prove it. Our plan was to begin in the present at Yardi Lake and walk backward through time, peeling away what makes us human, trait by trait, species by species. Herto: e Ancient Familiar I dozen sci- entists and students and six armed guards. Our caravan of 11 vehicles carried enough food and equipment for six weeks. As we threaded through the highlands, sharply terraced elds of sorghum and corn gave way to misted forests. e road was littered with the flotsam of mere history---around a bend the burned hulk of an army armored personnel car- rier from the civil war in the 1990s and, farther on, the eroded name " " carved in the lintel above a tunnel, a legacy of the Italian oc- cupation of the country in the 1930s. From the top of the escarpment we switch- backed down a gargantuan staircase formed as the Arabian continental plate pulled away from Africa beginning some 30 to 25 million years ago, dropping the Afar Basin ever deeper into the rain shadow of the highlands. As we descended, the vegetation grew thinner, the sun more intense. A few hundred yards above the basin oor, we pulled over. Below us the western hills in the foreground fell toward a ragged, fault-scarred plain. On the horizon to the southeast, beyond the green ribbon of the Awash River, the highlands seemed to merge with the cone of the young volcano Ayelu. Below Ayelu was a sliver of silver: Yardi Lake. Two days later we were walking along its shore---White, Asfaw, and WoldeGabriel, along with two longtime members of the project, geol- ogist Bill Hart of Miami University in Ohio and Ahamed Elema, the leader of the Bouri-Modaitu Afar clan. For a while we followed the lake mar- gin, bright dragon ies itting about our ankles. It was the perfect setting for making fossils, now as in the past. Animals come to eat, to drink, to kill and be killed. Bones get buried, rescued from decomposition. Over eons, water trickles miner- als in, organics out. White---58 years old, hard and thin as a jackal---poked with his long-han- dled ice ax at things newly dead. A cat sh skel- eton le by a sh eagle beneath an acacia tree. e head of a cow, still wearing a leathery mask of dried esh. "If you want to become a fossil," he said, "you can't do much better than this." Our rst day's walk would take us east across an upli ed nger of land called the Bouri Pen- insula, toward the Afar village of Herto. We emerged from the shade of the lake fringe and crossed some low, gray sand dunes. Soon an Afar boy and girl came with their herd of goats to in- vestigate. e Afar are pastoralists, and except for the addition of rearms, their lives today are not substantially di erent from the way they were 500 years ago. As we walked in the heat among Jamie Shreeve is National Geographic's science editor and author of e Genome War.