Has Humanity’s Homeland Been Found?

Earlier this year, while flying over northern Botswana, Vanessa Hayes looked out over the Makgadikgadi Pans—giant salt flats that stretch for more than 6,000 square miles. They are the remnants of what was once Africa’s largest lake. Hayes could see traces of the lake’s shoreline from the air. She glimpsed massive fault lines running across its former bed—signs of the tectonic activity that eventually broke it apart into a patchwork of lush wetlands. For Hayes, who is a geneticist at the Garvan Institute of Medical Research, the view carried a special significance. She thinks that this region was once humanity’s homeland—the place where the ancestors of modern humans got their start.

Hayes and her team analyzed the DNA of 1,217 people from southern Africa who represent a particularly important and poorly studied slice of human genetic diversity. By using that DNA to create a family tree, that anatomically modern humans originated in the Makgadikgadi wetlands about 200,000 years