For most of human history, people lived by hunting, fishing and gathering wild plants. Then, in several parts of the world, people began to plant seeds and tend animals. Farming is a great example of the diffusion you have studied: it began in a few hearths and spread.
Key idea
Farming began about 10,000 to 12,000 years ago, starting in the Fertile Crescent of Southwest Asia, and arose independently in several hearths: China, Mesoamerica, the Andes, New Guinea, Africa's Sahel and eastern North America. Each hearth domesticated its own plants and animals.
| Hearth | About when | Early crops and animals |
|---|---|---|
| Fertile Crescent (Southwest Asia) | about 10,000 BC | Wheat, barley, lentils; sheep, goats, cattle |
| China (Yellow and Yangtze rivers) | about 8000-7000 BC | Millet in the north, rice in the south; pigs |
| Mesoamerica (Mexico) | about 7000 BC (maize) | Maize (corn), beans, squash |
| Andes (Peru, Bolivia) | about 5000 BC | Potatoes, quinoa; llamas, alpacas |
| New Guinea highlands | about 7000-5000 BC | Taro, bananas |
| Sahel and West Africa | about 3000-2000 BC | Sorghum, pearl millet, African rice |
| Eastern North America | about 3000 BC | Sunflower, squash and other seed plants |
Why it works
How do we know the hearths were independent? The crops differ. Wheat came from wild grasses of Southwest Asia, maize from a wild Mexican grass called teosinte, and the potato from wild Andean plants. None of these wild plants grew in the other hearths, so each farming system had to begin where its wild ancestors lived. Afterward, crops spread far: wheat to Europe, maize to the whole world after 1492.
Worked example: Match a crop to its hearth
Archaeologists find early domesticated potatoes. In which hearth were they most likely grown?
- Potatoes came from wild relatives in the highlands of South America.
- That is the Andes hearth (today's Peru and Bolivia).
Answer: The Andes.
Worked example: One hearth or many?
Maize was being farmed in Mexico thousands of years before anyone in the Americas could have learned of wheat farming in Southwest Asia. What does that tell us?
- There was no contact across the oceans then.
- Farming in Mesoamerica used a local plant, teosinte, turned into maize.
- So it began there on its own.
Answer: Farming arose independently in more than one hearth.
Common mistake
Thinking farming was invented once and spread from one place. It began separately in several regions, each with its own crops and animals. Diffusion came later, as crops and ideas spread out from each hearth.