EAST AFRICA AND MAN
BUT WERE THE Australopithecinæ direct ancestors? Were they in the direct line that led to Homo sapiens, to ourselves? The whole moot question was hotly debated.
All the while, the answer was being sought in the ancient soil of East Africa as well as in the South. The high dry plateaus and the gorges looked like promising places to search. For many years Louis S. B. Leakey, curator of the Coryndon Museum, Nairobi, Kenya, had been finding very primitive chipped-stone tools in the lower strata of a deep Tanganyika gorge. Like the South African tools, only a few chips had been removed from them, but this flaking method had been used over and over again to turn a hand-sized piece of stone into an effective tool for skinning an animal, and perhaps for killing one. Again it was certain; no animal could have made such tools. Here was man. Leakey named the unknown's tools "Oldowan," for the gorge, Olduvai (also spelled Oldoway).
More than half a million years ago, the strata of the gorge revealed, a lake had filled the area. In wet periods the waters rose and spread across the countryside. In dry periods the lake receded into a narrower depression. In the end, as the climate grew increasingly dry and earth movements occurred, the lake disappeared altogether.
Many years after its water had gone and the old lake bed had been covered deep by the drifting African sands, the region was shaken by a violent earthquake. Its tremors opened a deep crack stretching from the former lake basin into the