Richard Erskine Frere Leakey was born on December 19, 1944, in Nairobi, Kenya. Continuing the work of his parents, Leakey has pushed the date for the appearance of the first true humans back even further than they had, to nearly three million years ago. This represents nearly a doubling of the previous estimates. Leakey also has found more evidence to support his father's still controversial theory that there were at least two parallel branches of human evolution, of which only one was successful. The abundance of human fossils uncovered by Richard Leakey's team has provided an enormous number of clues as to how the various fossil remains fit into the puzzle of human evolution. The team's finds have also helped to answer, if only speculatively, some basic questions: When did modern human's...