Agriculture has changed dramatically since ... The decline of ancient civilizations in Mesopotamia, the Mediterranean region, Pre-Columbian southwest U.S. and Central America is believed to ...

Mesopotamia, between the Tigris and Euphrates ... is that the Sumerian civilization declined because productivity in agriculture gradually decreased. Since the Euphrates and Tigris rivers brought ...

The oldest reference in the first known writing — cuneiform — was not about gods or kings, but about beer. Lots of it. It was ...