Early civilizations independently develop irrigation, transforming how humans grow food
Irrigation emerged around 6,000 years ago in at least four corners of the world at once — Mesopotamia, Egypt, the Indus Valley, and China — with farmers in each place learning to channel rivers onto dry fields. Along the Tigris and Euphrates, the earliest known canals redirected water into otherwise barren land. It’s one of history’s clearest cases of parallel invention.





