The Nile River seen at sunrise. (Credit: Kirsty Bisset/Shutterstock)

Thousands of years ago, ancient Egyptians built their agricultural systems around the dependable movement of the Nile. Those rhythms date back much further than any human relative has been alive, scientists now find.

New research shows that the Nile has kept about the same course for its entire 30 million year existence. This is likely thanks to a reliable flow of rocky material just below the Earth’s surface, which cont