For many years Mary Leakey lived in the shadow of her husband, Louis Leakey, whose reputation, coupled with the prejudices of the time, led him to be credited with some of his wife's discoveries in the field of early human archaeology. Yet she established a substantial reputation in her own right and came to be recognized as one of the most important paleoanthropologists of the twentieth century. It was Mary Leakey who was responsible for some of the most important discoveries made by Louis Leakey's team. Although her close association with Louis Leakey's work on Paleolithic sites at Olduvai Gorge--a 350-mile ravine in Tanzania--led to her being considered a specialist in that particular area and period, she in fact worked on excavations dating from as early as the Miocene, (an era dating to approximately 18 million years ago) to those as recent as the Iron Age of a few...