Cradle of humanity found?
Researchers claim to have traced the “homeland” of modern humanity to Botswana. “We have known for a long time that modern humans originated in Africa,” senior author Vanessa Hayes, from the Garvan Institute of Medical Research in Sydney, tells The Guardian. “What we hadn’t known until this study was where exactly.” Hayes’ team based their conclusion on an analysis of 1,217 samples of mitochondrial DNA from people living in southern Africa today, along with geological, archaeological, and fossil evidence. They posit that about 200,000 years ago, our ancestors settled near a huge lake system—now sprawling salt flats—in northern Botswana that was starting to break apart. That would have created a vast wetland brimming with life. After 70,000 years, changes in rainfall opened up corridors of vegetation in the surrounding desert, enabling humans to migrate, first to the northeast and later to the southwest. The analysis has been criticized by some geneticists. They say mitochondrial DNA cannot be used to pinpoint geographical origins in this way, and that lineages in other regions should have been included in the study. ■