the study provides insight into the early demographic history of human populations before they moved out of Africa. “These early human populations were small and isolated from each other for many tens of thousands of years,” says Rosset. MtDNA, inherited down the maternal line, was used in 1987 to discover the age of the famous “Mitochondrial Eve,” the most recent common female ancestor of everyone alive today. This work has since been extended to show unequivocally that “Mitochondrial Eve” was an African woman who lived sometime during the past 200,000 years.