for up to 60 million years. Agriculture is defined with varying scopes, in its broadest sense using natural resources to "produce commodities which maintain life, including food, fiber, forest products, horticultural crops, and their related services". Thus defined, it includes arable farming, horticulture, animal husbandry and forestry, but horticulture and forestry are in practice often excluded. It may also be broadly decomposed into plant agriculture, which concerns the cultivation of useful plants, and animal agriculture, the production of agricultural animals. History Origins The development of agriculture enabled the human population to grow many times larger than could be sustained by hunting and gathering. Agriculture began independently in different parts of the globe, and included a diverse range of taxa, in at least 11 separate centers of origin. Wild grains were collected and eaten from at least 105,000 years ago. In the Paleolithic Levant, 23,000 years ago, cereals cultivation of emmer, barley, and oats has been observed near the sea of Galilee. Rice was domesticated in China between 11,500 and 6,200 BC with the earliest known cultivation from 5,700 BC, followed by mung, soy and azuki beans. Sheep were domesticated in Mesopotamia between 13,000 and 11,000 years ago. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and Pakistan some 10,500 years ago. Pig production emerged in Eurasia, including Europe, East Asia and Southwest Asia, where wild boar were first domesticated about 10,500 years ago. In the Andes of South America, the potato was domesticated between 10,000 and 7,000 years ago, along with beans, coca, llamas, alpacas, and guinea pigs. Sugarcane and some root vegetables were domesticated in New Guinea around 9,000 years ago. Sorghum was domesticated in the Sahel region of Africa by 7,000 years ago. Cotton was domesticated in Peru by 5,600 years ago, and was independently domesticated in Eurasia. In Mesoamerica, wild teosinte was bred into maize by 6,000 years ago. The horse was domesticated in the Eurasian Steppes around 3500 BC. Scholars have offered multiple hypotheses to explain the historical origins of agriculture. Studies of the transition from hunter-gatherer to agricultural societies indicate an initial period of intensification and increasing sedentism; examples are the Natufian culture in the Levant, and the Early Chinese Neolithic in China. Then, wild stands that had previously been harvested started to be planted, and gradually came to be domesticated. Civilizations In Eurasia, the Sumerians started to live in