B
Khan Academy
The world before agriculture
Based on current archeological evidence, anatomically modern humans have existed roughly 200,000-300,000 years. However, before roughly 15,000-20,000 years ago, we have no evidence that our ancestors had agriculture. Instead, we believe they strictly hunted or foraged for food. If they didn’t find food, they or their families would starve.
There also couldn’t be too many humans living in one area since there was only so much food to be found or killed. Because of this, a tribe of 100 hunter-foragers would have needed to be the only humans on 50 to 500 square kilometers to survive—places lush with life, like tropical rain forests, could support a higher density. With only hunting and foraging to support human populations, it is estimated that the Earth could only support about 10 million people. Historians estimate the world population was around six to ten million 10,000 years ago.
