In 1989 an analysis of samples of mtDNA from 147 women from diverse parts of the world was interpreted by Dr. Rebecca Cann and colleagues as indicating that all the present-day women tested descended from the same ancestress, for they all shared certain mtDNA features that they could have received only from a common female ancestor. Using estimates of the rate of mutations in mtDNA as a basis, the investigators reasoned that this hypothetical common ancestor of the women from four continents had lived about 200,000 years ago in sub-Saharan Africa.18 This postulation, fertilized by journalistic simplification and hype, was parlayed into unhesitating statements in the press to the effect that "all human beings alive today shared one female ancestor--a kind of 'Eve'--in Africa 200,000 years ago."