History of agriculture
began independently in different parts of the globe, and included a diverse range of taxa. At least eleven separate regions of the Old and New World were involved as independent centers of origin.
The development of agriculture about 12,000 years ago changed the way humans lived. They switched from nomadic hunter-gatherer lifestyles to permanent settlements and farming.
Wild grains were collected and eaten from at least 104,000 years ago. However, domestication did not occur until much later. The earliest evidence of small-scale cultivation of edible grasses is from around 21,000 BC with the Ohalo II people on the shores of the Sea of Galilee. By around 9500 BC, the eight Neolithic founder crops – emmer wheat, einkorn wheat, hulled barley, peas, lentils, bitter vetch, chickpeas, and flax – were cultivated in the Levant. Rye may have been cultivated earlier, but this claim remains controversial. Regardless, rye's spread from Southwest Asia to the Atlantic was independent of the Neolithic founder crop package. Rice was domesticated in China by 6200 BC with earliest known cultivation from 5700 BC, followed by mung, soy and azuki beans. Rice was also independently domesticated in West Africa and cultivated by 1000 BC. Pigs were domesticated in Mesopotamia around 11,000 years ago, followed by sheep. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and India around 8500 BC. Camels were domesticated late, perhaps around 3000 BC.
In subsaharan Africa, sorghum was domesticated in the Sahel region of Africa by 3000 BC, along with pearl millet by 2000 BC. Yams were domesticated in several distinct locations, including West Africa, and cowpeas by 2500 BC. Rice was also independently domesticated in West Africa and cultivated by 1000 BC. Teff and likely finger millet were domesticated in Ethiopia by 3000 BC, along with noog, ensete, and coffee. Other plant foods domesticated in Africa include watermelon, okra, tamarind and black eyed peas, along with tree crops such as the kola nut and oil palm. Plantains were cultivated in Africa by 3000 BC and bananas by 1500 BC. The helmeted guineafowl was domesticated in West Africa. Sanga cattle was likely also domesticated in North-East Africa, around 7000 BC, and later crossbred with other species.
In South America, agriculture began as early as 9000 BC, starting with the cultivation of several species of plants that later became only minor crops. In the Andes of South America, the potato was domesticated between 8000 BC and 5000 BC, along with beans, squash, tomatoes, peanuts, coca, llamas, alpacas, and guinea pigs. Cassava was domesticated in the Amazon Basin no later than 7000 BC. Maize found its way to South America from Mesoamerica, where wild teosinte was domesticated about 7000 BC and selectively bred to become domestic maize. Cotton was domesticated in Peru by 4200 BC; another species of cotton was domesticated in Mesoamerica and became by far the most important species of cotton in the textile industry in modern times. Evidence of agriculture in the Eastern United States dates to about 3000 BCE. Several plants were cultivated, later to be replaced by the Three Sisters cultivation of maize, squash, and beans.
Sugarcane and some root vegetables were domesticated in New Guinea around 7000 BC. Bananas were cultivated and hybridized in the same period in Papua New Guinea. In Australia, agriculture was invented at a currently unspecified period, with the oldest eel traps of Budj Bim dating to 6,600 BC and the deployment of several crops ranging from murnong to bananas.
The Bronze Age, from, witnessed the intensification of agriculture in civilizations such as Mesopotamian Sumer, ancient Egypt, ancient Sudan, the Indus Valley civilisation of the Indian subcontinent, ancient China, and ancient Greece. From 100 BC to 1600 AD, world population continued to grow along with land use, as evidenced by the rapid increase in methane emissions from cattle and the cultivation of rice. During the Iron Age and era of classical antiquity, the expansion of ancient Rome, both the Republic and then the Empire, throughout the ancient Mediterranean and Western Europe built upon existing systems of agriculture while also establishing the manorial system that became a bedrock of medieval agriculture. In the Middle Ages, both in Europe and in the Islamic world, agriculture was transformed with improved techniques and the diffusion of crop plants, including the introduction of sugar, rice, cotton and fruit trees such as the orange to Europe by way of Al-Andalus. After the voyages of Christopher Columbus in 1492, the Columbian exchange brought New World crops such as maize, potatoes, tomatoes, sweet potatoes, and manioc to Europe, and Old World crops such as wheat, barley, rice, and turnips, and livestock including horses, cattle, sheep, and goats to the Americas.
Irrigation, crop rotation, and fertilizers were introduced soon after the Neolithic Revolution and developed much further in the past 200 years, starting with the British Agricultural Revolution. Since 1900, agriculture in the developed nations, and to a lesser extent in the developing world, has seen large rises in productivity as human labour has been replaced by mechanization, and assisted by synthetic fertilizers, pesticides, and selective breeding. The Haber-Bosch process allowed the synthesis of ammonium nitrate fertilizer on an industrial scale, greatly increasing crop yields. Modern agriculture has raised social, political, and environmental issues including overpopulation, water pollution, biofuels, genetically modified organisms, tariffs and farm subsidies. In response, organic farming developed in the twentieth century as an alternative to the use of synthetic pesticides.
Origins
Origin hypotheses
Scholars have developed a number of hypotheses to explain the historical origins of agriculture. Studies of the transition from hunter-gatherer to agricultural societies indicate an antecedent period of intensification and increasing sedentism; examples are the Natufian culture in the Levant and the Early Chinese Neolithic in China. Current models indicate that wild stands that had been harvested previously started to be planted, but were not immediately domesticated.Localised climate change is the favoured explanation for the origins of agriculture in the Levant. When major climate change took place after the last ice age, much of the earth became subject to long dry seasons. These conditions favoured annual plants which die off in the long dry season, leaving a dormant seed or tuber. An abundance of readily storable wild grains and pulses enabled hunter-gatherers in some areas to form the first settled villages at this time. Across Western Eurasia it was not until approximately 4,000 BC that farming societies completely replaced hunter-gatherers. These technologically advanced societies expanded faster in areas with less forest, pushing hunter-gatherers into denser woodlands. Only the middle-late Bronze Age and Iron Age societies were able to fully replace hunter-gatherers in their final stronghold located in the most densely forested areas. Unlike their Bronze and Iron Age counterparts, Neolithic societies couldn't establish themselves in dense forests, and Copper Age societies had only limited success.
Early development
Early people began altering communities of flora and fauna for their own benefit through means such as fire-stick farming and forest gardening very early.Wild grains have been collected and eaten from at least 105,000 years ago, and possibly much longer. Exact dates are hard to determine, as people collected and ate seeds before domesticating them, and plant characteristics may have changed during this period without human selection. An example is the semi-tough rachis and larger seeds of cereals from just after the Younger Dryas in the early Holocene in the Levant region of the Fertile Crescent. Monophyletic characteristics were attained without any human intervention, implying that apparent domestication of the cereal rachis could have occurred quite naturally.
Agriculture began independently in different parts of the globe and included a diverse range of taxa. At least 11 separate regions of the Old and New World were involved as independent centers of origin. Some of the earliest known domestications were of animals. Domestic pigs had multiple centres of origin in Eurasia, including Europe, East Asia and Southwest Asia, where wild boar were first domesticated about 10,500 years ago. Sheep were domesticated in Mesopotamia between 11,000 BC and 9000 BC. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and India around 8500 BC. Camels were domesticated relatively late, perhaps around 3000 BC.
File:Vavilov-centers updated.jpg |thumb |300px |Centres of origin identified by Nikolai Vavilov in the 1930s. Area 3 is no longer recognised as a centre of origin, and Papua New Guinea was identified more recently.
It was not until after 9500 BC that the eight so-called founder crops of agriculture appear: first emmer and einkorn wheat, then hulled barley, peas, lentils, bitter vetch, chick peas and flax. These eight crops occur more or less simultaneously on Pre-Pottery Neolithic B sites in the Levant, although wheat may have been the first to be grown and harvested on a significant scale. At around the same time, parthenocarpic fig trees were domesticated.
Domesticated rye occurs in small quantities at some Neolithic sites in Turkey, such as the Pre-Pottery Neolithic B Can Hasan III near Çatalhöyük, but is otherwise absent until the Bronze Age of central Europe, c. 1800–1500 BC. Claims of much earlier cultivation of rye, at the Epipalaeolithic site of Tell Abu Hureyra in the Euphrates valley of northern Syria, remain controversial. Critics point to inconsistencies in the radiocarbon dates, and identifications based solely on grain, rather than on chaff.
By 8000 BC, farming was entrenched on the banks of the Nile. About this time, agriculture was developed independently in the Far East, probably in China, with rice rather than wheat as the primary crop. Maize was domesticated from the wild grass teosinte in southern Mexico by 6700 BC.
The potato, tomato, pepper, squash, and some varieties of bean were domesticated in the New World.
Agriculture was independently developed on the island of New Guinea. Banana cultivation of Musa acuminata, including hybridization, dates back to 5000 BC, and possibly to 8000 BC, in Papua New Guinea.
Bees were kept for honey in the Middle East around 7000 BC. Archaeological evidence from various sites on the Iberian peninsula suggest the domestication of plants and animals between 6000 and 4500 BC. The Céide Fields, located in Ireland consist of extensive tracts of land enclosed by stone walls, these walls date to 3500 BC and is the oldest known field systems in europe. The horse was domesticated in the Pontic steppe around 4000 BC In Siberia. Cannabis was in use in China in Neolithic times and may have been domesticated there; it was in use both as a fibre for ropemaking and as a medicine in Ancient Egypt by about 2350 BC.
In northern China, millet was domesticated by early Sino-Tibetan speakers at around 8000 to 6000 BC, becoming the main crop of the Yellow River basin by 5500 BC.
File:Chronological dispersal of Austronesian people across the Pacific.svg |thumb |left |upright=1.5 |Chronological dispersal of Austronesian peoples across the Indo-Pacific
In southern China, rice was domesticated in the Yangtze River basin at around 11,500 to 6200 BC, along with the development of wetland agriculture, by early Austronesian and Hmong-Mien-speakers. Other food plants were also harvested, including acorns, water chestnuts, and foxnuts. Rice cultivation was later spread to Maritime Southeast Asia by the Austronesian expansion, starting at around 3,500 to 2,000 BC. This migration event also saw the introduction of cultivated and domesticated food plants from Taiwan, Maritime Southeast Asia, and New Guinea into the Pacific Islands as canoe plants. Contact with Sri Lanka and Southern India by Austronesian sailors also led to an exchange of food plants which later became the origin of the valuable spice trade. In the 1st millennium AD, Austronesian sailors also settled Madagascar and the Comoros, bringing Southeast Asian and South Asian food plants with them to the East African coast, including bananas and rice. Rice was also spread southwards into Mainland Southeast Asia by around 2000 to 1500 BC by the migrations of the early Austroasiatic and Kra-Dai-speakers.
In the Sahel region of Africa, sorghum was domesticated by 3000 BC in Sudan and pearl millet by 2500 BC in Mali. Kola nut and coffee were also domesticated in Africa. In New Guinea, ancient Papuan peoples began practicing agriculture around 7000 BC, domesticating sugarcane and taro. In the Indus Valley from the eighth millennium BC onwards at Mehrgarh, 2-row and 6-row barley were cultivated, along with einkorn, emmer, and durum wheats, and dates. In the earliest levels of Merhgarh, wild game such as gazelle, swamp deer, blackbuck, chital, wild ass, wild goat, wild sheep, boar, and nilgai were all hunted for food. These are successively replaced by domesticated sheep, goats, and humped zebu cattle by the fifth millennium BC, indicating the gradual transition from hunting and gathering to agriculture.
Maize and squash were domesticated in Mesoamerica; potatoes in South America, and sunflowers in the Eastern Woodlands of North America.