In 1987, a group of molecular geneticists at the University of California at Berkeley offered support for the idea that anatomically modern humans arose fairly recently in Africa, then spread out and colonized the world. The geneticists analyzed genetic samples of 147 women whose ancestors came from Africa, Europe, the Middle East, Asia, New Guinea, and Australia. By estimating the number of mutations that had taken place in the mitochondrial DNA (mtDNA) of each of these samples, the researchers concluded that