Across the Cultures
T he end of the last Ice Age created unusually moist conditions in which wild grains flourished. They were gathered by nomadic peoples, who gradually began to experiment by scattering the grain so that it would grow again. In this way they eventually transplanted the wild grains from their natural habitat-the mountains that fringe the region-to the fertile valleys of the Euphrates and the Tigris rivers. When people started to plant crops deliberately in one place, they had to stay in the same place (or return to it) to harvest the crop. So over time wandering hunter-gatherers became settled people.