Domestication

Domestication is a multi-generational mutualistic relationship in which an animal species, such as humans or leafcutter ants, takes over control and care of another species, such as sheep or fungi, so as to obtain from them a steady supply of resources, such as meat, milk, or labor. The process is gradual and geographically diffuse, based on trial and error.

The first animal to be domesticated by humans was the dog, as a commensal, at least 15,000 years ago. Other animals including goats, sheep, and cows were domesticated starting around 11,000 years ago. Among birds, the chicken was first domesticated in East Asia, seemingly for cockfighting, some 7,000 years ago. The horse came under domestication around 5,500 years ago in central Asia as a working animal. Among invertebrates, the silkworm and the western honey bee were domesticated over 5,000 years ago for silk and honey, respectively.

The domestication of plants began around 13,000–11,000 years ago with cereals such as wheat and barley in the Middle East, alongside crops such as lentil, pea, chickpea, and flax. Rice was first cultivated in China some 13,500 to 8,200 years ago. Beginning around 10,000 years ago, Indigenous peoples in the Americas began to cultivate peanuts, squash, maize, potatoes, cotton, and cassava. In Africa, crops such as sorghum were domesticated. Agriculture developed in some 13 centres around the world, domesticating different crops and animals.

Domestication affected genes for behavior in animals, making them less aggressive. In plants, domestication affected genes for morphology, such as increasing seed size and stopping the shattering of seed-heads such as in wheat. Such changes both make domesticated organisms easier to handle, and reduce their ability to survive in the wild.