It is one of the least hospitable places on earth. A steady wind moans over the crocodiles basking on the banks of blue-green Lake Turkana and flattens the knee-high beach grass where the long-horned oryx graze. Beyond stretches the desert of northeast Kenya, baked by the African sun. In a wadi, or dried-up stream bed, not far away, a sandy-haired man moves slowly, his loose shorts and shirt flapping in the breeze, his head bare to the sun, his eyes searching the arid soil at his feet. Some 50 ft. away, sandals scuffing dust into the air behind her. his wife keeps pace, her eyes sweeping the ground. An African, remainder of the party.
Suddenly the leader stops, stoops and snatches a small brownish fossilized bone fragment out of the sand. "Nimeipata, " he says in Swahili to the man beside him. "I've got it." Then, "Meave!" he calls to the wom an, who runs to join him. Together they examine the bone for a moment, replace it on the exact spot where it was found, mark it with a stake, and resume their search.
The intent man in the desert is Richard Erskine Leakey, heir to one of the greatest surnames in anthropology and, at 32, a formidable scientist in his own right. He and his dusty band are looking, almost lit erally, for footprints in the sands of time, for clues to the mystery of man's origins. Their ambitious goal: to establish the nature of the creatures that veered off from the ancestral line of apes onto the evolutionary path that eventually led to man. In this pursuit, Leakey's team has turned up at the Turkana site alone more than 300 fossilized bone specimens, from an estimated 1 80 of man's ancestors. All told, during a decade-long Leakey has found more and better pre-man and early man fossils than any other anthropologist. His work has helped upset many held ideas on evolution and has forced science to write a new sce nario for man's slow progress from ape to Shakespeare's "paragon of animals," Homo sapiens.
Elsewhere around the world, other scientists are examining fossils, stone tools, soil and rock samples, and even pollen grains in an effort to find more of the missing pieces in the puzzle of man's ascent. They are motivated not only by curiosity and dedication to their science but also by the knowledge that what they discover may help man to understand himself. Says Leak ey in his just-published Origins (Dutton; $17.95): "By searching our long-buried past for an understanding of what we are, we may discover some insight into our future."
Long before the search for relatively contemporary roots be came a popular pastime, man sought to account for his ultimate origins. In the Middle Ages he looked to the Bible for the answer Turning to the book of Genesis, which says that God created man on the sixth day. James Ussher, the Archbishop of Armaugh, decided in 1650 to determine when that day had occurred By calculating backward through all the biblical "begats" he figured that man was created in 4004 B.C. John Lightfoot, master of St. Catherine's College at the University of Cambridge, shortly thereafter pinpointed the time of the momentous event even more precisely. He announced that it had occurred on Oct. 23 at 9 a.m.
The finding of crude tools, weapons and other