14 DAY TRIAL // Roughly 100,000 – 130,000 years ago, the African monsoon brought heavy rains some 1,000 kilometers (621 miles) farther north than it presently does.
Researchers say that, in those days, the land that is now the Sahara Desert found itself crisscrossed by three major river systems.
Each of these rivers used to carry about 25% of the water the Nile now carries, computer simulations indicate. Lakes and deltas were part of the package deal.
Nature reports that, according to a recent study, these three river systems were what made it possible for early humans to move out of Africa and head towards Europe and Asia.
Thus, early modern human migrations would have probably never taken place in the absence of vegetation and water in these regions.
As paleoclimatologist Mike Rogerson put it, “The rivers would have created 'green corridors' of vegetation and water in the desert, enabling early modern humans to migrate north and eventually to other continents.”