In testing the genetic material of current populations in Africa and comparing against existing fossil evidence of early Homo sapiens populations there, researchers have uncovered a new model of human evolution — overturning previous beliefs that a single African population gave rise to all humans. In this study, published in the journal ‘Nature’, the researchers included newly sequenced genomes from 44 modern Nama individuals from southern Africa, an indigenous population known to carry exceptional levels of genetic diversity compared to other modern groups. They found that earliest population split among early humans occurred 120,000 to 135,000 years ago, after two or more weakly genetically differentiated Homo populations had been mixing for hundreds of thousands of years. After the population split, people still migrated between the stem populations, creating a weakly structured stem. This offers a better explanation of genetic variation among human groups than do previous models, the research suggests.