National Geographic : 1998 Aug
The first australopithecine fossil made inter national headlines in 1925, after anatomist Raymond Dart identified an africanus skull unearthed in South Africa. Excavations there tapered off in the 1950s as the spotlight swung to East Africa with the pioneering work of Louis and Mary Leakey and the later discov eries of Richard and Meave Leakey, Tim White, Donald Johanson, and others. Now my studies and those of other colleagues are drawing the spotlight back to the unsung hominids of southern Africa. In the past, based on work in East Africa, many scientists placed Australopithecus afaren sis at the base of the family tree and drew a line leading ultimately to our own genus, Homo. Lucy, the best known afarensis, roamed the savannas and woodlands of the Great Rift Valley between 3.9 and 3 million years ago. When I first came to South Africa, I accepted the hypothesis that Lucy and her kind were the ancestors of all later hominids-until I studied the Sterkfontein fossils. To prove my theory, Henry McHenry and I compared more than a hundred fossil bones from Sterkfontein and Hadar, the Ethiopian site where Lucy was found. We also included two partial skeletons: Lucy herself and STW 431, a male africanusfrom Sterkfontein. On Henry's first visit to my lab we emptied the safe of all the limb bones-about 20 percent of Africa's hominid specimens. We laid them REDRAWING OUR FAMILY TREE?