A social cause is a problem that influences a considerable number of individuals within a society. It is the consequence of factors extending beyond an individual's control, is the source of a conflicting opinion on the grounds of what is perceived as a morally just personal life or societal order. Social issues are distinguished from economic issues. There are issues that don't fall into either category, such as warfare. There can be disagreements about what social issues are worth solving, or which should take precedence. Different individuals and different societies have different perceptions. In Rights of Man and Common Sense, Thomas Paine addresses individual's duty to "allow the same rights to others as we allow ourselves"; the failure to do so caused the birth of a social issue. There are a variety of methods; some people vote for leaders in a democracy to advance their ideals. Outside the political process, people donate or share their time, energy, or other resources; this takes the form of volunteering.
Nonprofit organizations are formed for the sole purpose of solving a social issue. Community organizing involves gathering people together for a common purpose. A distinct but related meaning of the term "social issue" refers to topics of national political interest, over which the public is divided and which are the subject of intense partisan advocacy and voting. Examples include same-sex abortion. In this case "social issue" does not refer to an ill to be solved, but rather to a topic to be discussed. Personal issues are those that individuals deal with themselves and within a small range of their peers and relationships. On the other hand, social issues involve values cherished by widespread society. For example, a high unemployment rate that affects millions of people is a social issue; the line between a personal issue and a public issue may be subjective and depends on how groups are defined. However, when a large enough sector of society is affected by an issue, it becomes a social issue.
Returning to the unemployment issue, while one person losing their job is a personal and not a social issue, firing 13 million people is to generate a variety of social issues. A valence issue is a social problem; these types of issues generate a widespread consensus and provoke little resistance from the public. An example of a valence issue would be child abuse, condemned across several societies to a large enough degree that some social scientists might speak of them as though they are universal, for the sake of illustration. By contrast, a position issue is a social problem in which the popular opinion among society is divided. Different people may hold different and strongly-held views, which are not changed. An example of a position issue is abortion, which has not generated a widespread consensus from the public, in some countries. Here are some generic types of social issues, along with examples of each. Unemployment rates vary by region, educational attainment, ethnic group. In most countries, many people depend on welfare.
In 2007 in Germany, one in six children depended on welfare. That is up from only one in seventy-five in 1965. So-called "problem neighbourhoods" exist in many countries; these neighbourhoods tend to have a high drop-out rate from secondary school, children growing up in these neighbourhoods have a low probability of going to college compared to children who grow up in other neighbourhoods. Abuse of alcohol and drugs is common in these neighbourhoods; these neighbourhoods were founded out of best intentions. Widespread health conditions are of concern to society as a whole, they can harm quality of life and the ability of people to contribute to society and to work, most problematically result in death. Infectious diseases are public health concerns because they can spread and affecting large numbers of members; the World Health Organization has an acute interest in combatting infectious disease outbreaks by minimizing their geographic and numerical spread and treating the affected. Other conditions for which there is not yet a cure or effective treatment, such as dementia, can be viewed as public health concerns in the long run.
Throughout the life course, there are social problems associated with different ages. One such social problem is age discrimination. An example of age discrimination is when a particular person is not allowed to do something or is treated differently based on age. Social inequality is "the state or quality of being unequal". Inequality is the root of a number of social problems that occur when things such as gender, disability and age may affect the way a person is treated. A past example of inequality as a social problem is slavery in the United States. Africans brought to America were enslaved and mistreated, did not share the same rights as the white population of America. A number of civil rights movements have attempted to, succeeded at, advancing equality and extending rights to marginalized groups; these include the women's rights movement, the civil rights movement in the United States for African-American equality and the LGBT rights movement. Education is arguably the most important factor in a person's success in society.
As a result, social problems can be raised by the unequal distribution of funding
Forestry is the science and craft of creating, using and repairing forests and associated resources for human and environmental benefits. Forestry is practiced in natural stands; the science of forestry has elements that belong to the biological, social and managerial sciences. Modern forestry embraces a broad range of concerns, in what is known as multiple-use management, including the provision of timber, fuel wood, wildlife habitat, natural water quality management, recreation and community protection, aesthetically appealing landscapes, biodiversity management, watershed management, erosion control, preserving forests as "sinks" for atmospheric carbon dioxide. A practitioner of forestry is known as a forester. Other common terms are: a silviculturalist. Silviculture is narrower than forestry, being concerned only with forest plants, but is used synonymously with forestry. Forest ecosystems have come to be seen as the most important component of the biosphere, forestry has emerged as a vital applied science and technology.
Forestry is an important economic segment in various industrial countries. For example, in Germany, forests cover nearly a third of the land area, wood is the most important renewable resource, forestry supports more than a million jobs and about €181 billion of value to the German economy each year; the preindustrial age has been dubbed by Werner Sombart and others as the'wooden age', as timber and firewood were the basic resources for energy and housing. The development of modern forestry is connected with the rise of capitalism, economy as a science and varying notions of land use and property. Roman Latifundiae, large agricultural estates, were quite successful in maintaining the large supply of wood, necessary for the Roman Empire. Large deforestations came with after the decline of the Romans; however in the 5th century, monks in the Byzantine Romagna on the Adriatic coast, were able to establish stone pine plantations to provide fuelwood and food. This was the beginning of the massive forest mentioned by Dante Alighieri in his 1308 poem Divine Comedy.
Similar sustainable formal forestry practices were developed by the Visigoths in the 7th century when, faced with the ever-increasing shortage of wood, they instituted a code concerned with the preservation of oak and pine forests. The use and management of many forest resources has a long history in China as well, dating back to the Han dynasty and taking place under the landowning gentry. A similar approach was used in Japan, it was later written about by the Ming dynasty Chinese scholar Xu Guangqi. In Europe, land usage rights in medieval and early modern times allowed different users to access forests and pastures. Plant litter and resin extraction were important, as pitch was essential for the caulking of ships and hunting rights and building, timber gathering in wood pastures, for grazing animals in forests; the notion of "commons" refers to the underlying traditional legal term of common land. The idea of enclosed private property came about during modern times. However, most hunting rights were retained by members of the nobility which preserved the right of the nobility to access and use common land for recreation, like fox hunting.
Systematic management of forests for a sustainable yield of timber began in Portugal in the 13th century when Afonso III of Portugal planted the Pinhal do Rei near Leiria to prevent coastal erosion and soil degradation, as a sustainable source for timber used in naval construction. His successor Dom Dinis continued the forest exists still today. Forest management flourished in the German states in the 14th century, e.g. in Nuremberg, in 16th-century Japan. A forest was divided into specific sections and mapped; as timber rafting allowed for connecting large continental forests, as in south western Germany, via Main, Neckar and Rhine with the coastal cities and states, early modern forestry and remote trading were connected. Large firs in the black forest were called "Holländer ``. Large timber rafts on the Rhine were 200 to 400m in length, 40m in width and consisted of several thousand logs; the crew consisted of 400 to 500 men, including shelter, bakeries and livestock stables. Timber rafting infrastructure allowed for large interconnected networks all over continental Europe and is still of importance in Finland.
Starting with the sixteenth century, enhanced world maritime trade, a boom in housing construction in Europe and the success and further Berggeschrey of the mining industry increased timber consumption sharply. The notion of'Nachhaltigkeit', sustainability in forestry, is connected to the work of Hans Carl von Carlowitz, a mining administrator in Saxony, his book Sylvicultura oeconomica, oder haußwirthliche Nachricht und Naturmäßige Anweisung zur wilden Baum-Zucht was the first comprehensive treatise about sustainable yield forestry. In the UK, and, to an extent, in continental Europe, the enclosure movement and the clearances favored enclosed private property; the Agrarian reformers, early economic writers and scientists tried to get rid of the traditional commons. At the time, an alleged tragedy of the commons together with fears of a Holznot, an imminent wood shortage played a watershed role in the controversies about cooperative land use patterns; the practice of establishing tree plantations in the British Isles was promoted by John Evelyn, though it had acquired some populari
Nature Conservancy Council
The Nature Conservancy Council was a United Kingdom government agency responsible for designating and managing National Nature Reserves and other nature conservation areas in Great Britain between 1973 and 1991. The NCC was established by the Nature Conservancy Council Act 1973 and replaced the Nature Conservancy, established by Royal Charter in 1949. NCC's duties included: Managing national nature reserves; the organisation was divided into the three countries, each of, divided in turn into regions covering several counties. Specialist groups dealt with nationwide issues, such as geology, grasslands, birds, other taxonomic groups etc. There was a national headquarters, at first in Belgrave Square in London, but in Peterborough. Peter Bridgewater In 1991, following the passage of the Environmental Protection Act 1990 and the Natural Heritage Act 1991, the Nature Conservancy Council was divided into three: The Scottish part was amalgamated with the Countryside Commission for Scotland to become Scottish Natural Heritage.
The Welsh part was amalgamated with the Welsh part of the Countryside Commission for England and Wales to become the Countryside Council for Wales. The remaining English part became English Nature, remaining separate from the Countryside Commission, which became an England-only body. A non-statutory Joint Nature Conservation Committee was set up, to coordinate nature conservation between the three country agencies, to deal with the UK's contributions to international nature conservation; the History of Conservation Legislation in the UK, on naturenet
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, space navigation, it is the term of art used for the specialized knowledge used by navigators to perform navigation tasks. All navigational techniques involve locating the navigator's position compared to known locations or patterns. Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and direction. In this sense, navigation includes pedestrian navigation. In the European medieval period, navigation was considered part of the set of seven mechanical arts, none of which were used for long voyages across open ocean. Polynesian navigation is the earliest form of open-ocean navigation, it was based on memory and observation recorded on scientific instruments like the Marshall Islands Stick Charts of Ocean Swells.
Early Pacific Polynesians used the motion of stars, the position of certain wildlife species, or the size of waves to find the path from one island to another. Maritime navigation using scientific instruments such as the mariner's astrolabe first occurred in the Mediterranean during the Middle Ages. Although land astrolabes were invented in the Hellenistic period and existed in classical antiquity and the Islamic Golden Age, the oldest record of a sea astrolabe is that of Majorcan astronomer Ramon Llull dating from 1295; the perfecting of this navigation instrument is attributed to Portuguese navigators during early Portuguese discoveries in the Age of Discovery. The earliest known description of how to make and use a sea astrolabe comes from Spanish cosmographer Martín Cortés de Albacar's Arte de Navegar published in 1551, based on the principle of the archipendulum used in constructing the Egyptian pyramids. Open-seas navigation using the astrolabe and the compass started during the Age of Discovery in the 15th century.
The Portuguese began systematically exploring the Atlantic coast of Africa from 1418, under the sponsorship of Prince Henry. In 1488 Bartolomeu Dias reached the Indian Ocean by this route. In 1492 the Spanish monarchs funded Christopher Columbus's expedition to sail west to reach the Indies by crossing the Atlantic, which resulted in the Discovery of the Americas. In 1498, a Portuguese expedition commanded by Vasco da Gama reached India by sailing around Africa, opening up direct trade with Asia. Soon, the Portuguese sailed further eastward, to the Spice Islands in 1512, landing in China one year later; the first circumnavigation of the earth was completed in 1522 with the Magellan-Elcano expedition, a Spanish voyage of discovery led by Portuguese explorer Ferdinand Magellan and completed by Spanish navigator Juan Sebastián Elcano after the former's death in the Philippines in 1521. The fleet of seven ships sailed from Sanlúcar de Barrameda in Southern Spain in 1519, crossed the Atlantic Ocean and after several stopovers rounded the southern tip of South America.
Some ships were lost, but the remaining fleet continued across the Pacific making a number of discoveries including Guam and the Philippines. By only two galleons were left from the original seven; the Victoria led by Elcano sailed across the Indian Ocean and north along the coast of Africa, to arrive in Spain in 1522, three years after its departure. The Trinidad sailed east from the Philippines, trying to find a maritime path back to the Americas, but was unsuccessful; the eastward route across the Pacific known as the tornaviaje was only discovered forty years when Spanish cosmographer Andrés de Urdaneta sailed from the Philippines, north to parallel 39°, hit the eastward Kuroshio Current which took its galleon across the Pacific. He arrived in Acapulco on October 8, 1565; the term stems from the 1530s, from Latin navigationem, from navigatus, pp. of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" and the root of agere "to drive". The latitude of a place on Earth is its angular distance north or south of the equator.
Latitude is expressed in degrees ranging from 0° at the Equator to 90° at the North and South poles. The latitude of the North Pole is 90° N, the latitude of the South Pole is 90° S. Mariners calculated latitude in the Northern Hemisphere by sighting the North Star Polaris with a sextant and using sight reduction tables to correct for height of eye and atmospheric refraction; the height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so. Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the prime meridian or Greenwich meridian. Longitude is expressed in degrees ranging from 0° at the Greenwich meridian to 180° east and west. Sydney, for example, has a longitude of about 151° east. New York City has a longitude of 74° west. For most of history, mariners struggled to determine longitude. Longitude can be calculated. Lacking that, one can use a sextant to take a lunar distance that, with a nautical almanac, can be used to calculate the time at zero longitude.
Reliable marine chronometers were unavailable until the late 18th century and not affordable until the 19th century. For about a hundred years, from about 1767 until about 1850, mariners lacking a chronometer used the method of lunar distances to determine Greenwich time to find their longitude. A mariner with a chronometer could check its reading using a lunar determination of Greenwich tim
A national park is a park in use for conservation purposes. It is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently, there is a common idea: the conservation of'wild nature' for posterity and as a symbol of national pride. An international organization, the International Union for Conservation of Nature, its World Commission on Protected Areas, has defined "National Park" as its Category II type of protected areas. While this type of national park had been proposed the United States established the first "public park or pleasuring-ground for the benefit and enjoyment of the people", Yellowstone National Park, in 1872. Although Yellowstone was not termed a "national park" in its establishing law, it was always termed such in practice and is held to be the first and oldest national park in the world. However, the Tobago Main Ridge Forest Reserve, the area surrounding Bogd Khan Uul Mountain are seen as the oldest protected areas, predating Yellowstone by nearly a century.
The first area to use "national park" in its creation legislation was the U. S.'s Mackinac, in 1875. Australia's Royal National Park, established in 1879, was the world's third official national park. In 1895 ownership of Mackinac National Park was transferred to the State of Michigan as a state park and national park status was lost; as a result, Australia's Royal National Park is by some considerations the second oldest national park now in existence. Canada established Parks Canada in 1911, becoming the world's first national service dedicated to protecting and presenting natural and historical treasures; the largest national park in the world meeting the IUCN definition is the Northeast Greenland National Park, established in 1974. According to the IUCN, 6,555 national parks worldwide met its criteria in 2006. IUCN is still discussing the parameters of defining a national park. National parks are always open to visitors. Most national parks provide outdoor recreation and camping opportunities as well as classes designed to educate the public on the importance of conservation and the natural wonders of the land in which the national park is located.
In 1969, the IUCN declared a national park to be a large area with the following defining characteristics: One or several ecosystems not materially altered by human exploitation and occupation, where plant and animal species, geomorphological sites and habitats are of special scientific and recreational interest or which contain a natural landscape of great beauty. In 1971, these criteria were further expanded upon leading to more clear and defined benchmarks to evaluate a national park; these include: Minimum size of 1,000 hectares within zones in which protection of nature takes precedence Statutory legal protection Budget and staff sufficient to provide sufficient effective protection Prohibition of exploitation of natural resources qualified by such activities as sport, fishing, the need for management, etc. While the term national park is now defined by the IUCN, many protected areas in many countries are called national park when they correspond to other categories of the IUCN Protected Area Management Definition, for example: Swiss National Park, Switzerland: IUCN Ia - Strict Nature Reserve Everglades National Park, United States: IUCN Ib - Wilderness Area Victoria Falls National Park, Zimbabwe: IUCN III - National Monument Vitosha National Park, Bulgaria: IUCN IV - Habitat Management Area New Forest National Park, United Kingdom: IUCN V - Protected Landscape Etniko Ygrotopiko Parko Delta Evrou, Greece: IUCN VI - Managed Resource Protected AreaWhile national parks are understood to be administered by national governments, in Australia national parks are run by state governments and predate the Federation of Australia.
In Canada, there are both national parks operated by the federal government and provincial or territorial parks operated by the provincial and territorial governments, although nearly all are still national parks by the IUCN definition. In many countries, including Indonesia, the Netherlands, the United Kingdom, national parks do not adhere to the IUCN definition, while some areas which adhere to the IUCN definition are not designated as national parks. In 1810, the English poet William Wordsworth described the Lake District as a sort of national property, in which every man has a right and interest who has an eye to perceive and a heart to enjoy; the painter George Catlin, in his travels through the American West, wrote during the 1830s that the Native Americans in the United States might be preserved...in a magnificent park... A nation's Park, containing man and beast, in all the wild and freshness of their nature's beauty! The first effort by the U. S. Federal government to set aside such protected lands was on 20 April 1832, when President Andrew Jackson signed legislation that the 22nd United States Congress had enacted to set aside four sections of land around what is now Hot Springs, Arkansas, to protect the natural, thermal springs and adjoining mountainsides for the futur
The Broads is a network of navigable rivers and lakes in the English counties of Norfolk and Suffolk. The lakes, known as broads, were formed by the flooding of peat workings; the Broads, some surrounding land, were constituted as a special area with a level of protection similar to a national park by the Norfolk and Suffolk Broads Act 1988. The Broads Authority, a special statutory authority responsible for managing the area, became operational in 1989; the area is 303 square kilometres, most of, in Norfolk, with over 200 kilometres of navigable waterways. There are seven rivers and 63 broads less than 4 metres deep. Thirteen broads are open to navigation, with a further three having navigable channels; some broads have navigation restrictions imposed on them in autumn and winter, although the legality of the restrictions is questionable. Although the terms Norfolk Broads and Suffolk Broads are used to identify specific areas within the two counties the whole area is referred to as the "Norfolk Broads".
The Broads has similar status to the national parks in Wales. Because of its navigation role the Broads Authority was established under its own legislation on 1 April 1989; the Broads Authority Act 2009, promoted through Parliament by the authority, is intended to improve public safety on the water. In January 2015 the Broads Authority approved a change in name of the area to the Broads National Park, to recognise that the status of the area is equivalent to the English National Parks, that the Broads Authority shares the same two first purposes as the English National Park Authorities, receives a National park grant; this followed a three-month consultation which resulted in support from 79% of consultees, including unanimous support from the 14 UK national parks and the Campaign for National Parks. Defra, the Government department responsible for the parks expressed it was content that the Authority would make its own decision on the matter; this is the subject of ongoing controversy among some Broads users who note that the Broads is not named in law as a National Park and claim the branding detracts from the Broads Authority's third purpose, to protect the interests of navigation.
In response to this the Broads Authority has stated that its three purposes will remain in equal balance and that the branding is for marketing the National Park qualities of the Broads. The Broads are administered by the Broads Authority. Special legislation gives the navigation of the waterways equal status with the conservation and public enjoyment of the area. Specific parts of the Broads have been awarded a variety of conservation designations, for instance: Special Protection Area status for an area named'Broadland' composed of 28 Sites of Special Scientific Interest Environmentally Sensitive Area status for parts of the Halvergate Marshes National nature reserve status for: Bure Marshes NNR Ant Broads & Marshes NNR Hickling Broad NNR Ludham - Potter Heigham NNR Redgrave and Lopham Fen Martham Broad NNR Calthorpe Broad NNR Mid-Yare NNRA specific project being considered under the UK Biodiversity Action Plan is re-introduction of the large copper butterfly, whose habitat has been reduced by reduction of fens.
The Broads, although administered by the Broads Authority, give their name to the Broadland local government district, while parts of the Broads lie within other council areas: North Norfolk, South Norfolk and Great Yarmouth and Waveney district in Suffolk. For many years the lakes known as broads were regarded as natural features of the landscape, it was only in the 1960s that Dr Joyce Lambert proved that they were artificial features—flooded medieval peat excavations. In the Middle Ages the local monasteries began to excavate the peatlands as a turbary business, selling fuel to Norwich and Great Yarmouth. Norwich Cathedral took 320,000 tonnes of peat a year; the sea levels began to rise, the pits began to flood. Despite the construction of windpumps and dykes, the flooding continued and resulted in the typical Broads landscape of today, with its reedbeds, grazing marshes and wet woodland. Various attempts were made to extend the navigable rivers; the longest-lasting was on the River Waveney, where an Act of Parliament passed on 17 March 1670 authorised improvements which included three locks, at Geldeston and Wainford.
The head of navigation became a new staithe at Bungay. The new section was a private navigation, not controlled by the Yarmouth Haven and Pier Commissioners, who had responsibility for the rest of the Broadland rivers, it remained in use until 1934 and, although the upper two locks have been replaced by sluices and Geldeston lock is derelict, the Environment Agency have negotiated with local landowners to allow use by canoes and unpowered vessels which can be portaged around the locks. The next attempt was to extend navigation on the River Bure from Coltishall to Aylsham, authorised by an Act of Parliament on 7 April 1773. Five locks were built, to bypass mills, at Coltishall, Oxnead Lamas, Oxnead and Aylsham. There were financial difficulties during construction, but the works were completed and opened in October 1779. At Aylsham, a 1-mile cut was made from the river to a terminal basin, where several warehouses were constructed. Despite the arrival of the railways in 1879, goods continued to be carried to Aylsham by wherries until 1912, when major flooding badly damaged the locks.
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Agriculture is the science and art of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities; the history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Pigs and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture into the twenty-first. Modern agronomy, plant breeding, agrochemicals such as pesticides and fertilizers, technological developments have increased yields, while causing widespread ecological and environmental damage. Selective breeding and modern practices in animal husbandry have increased the output of meat, but have raised concerns about animal welfare and environmental damage.
Environmental issues include contributions to global warming, depletion of aquifers, antibiotic resistance, growth hormones in industrial meat production. Genetically modified organisms are used, although some are banned in certain countries; the major agricultural products can be broadly grouped into foods, fibers and raw materials. Food classes include cereals, fruits, meat, milk and eggs. Over one-third of the world's workers are employed in agriculture, second only to the service sector, although the number of agricultural workers in developed countries has decreased over the centuries; the word agriculture is a late Middle English adaptation of Latin agricultūra, from ager, "field", which in its turn came from Greek αγρός, cultūra, "cultivation" or "growing". While agriculture refers to human activities, certain species of ant and ambrosia beetle cultivate crops. Agriculture is defined with varying scopes, in its broadest sense using natural resources to "produce commodities which maintain life, including food, forest products, horticultural crops, their related services".
Thus defined, it includes arable farming, animal husbandry and forestry, but horticulture and forestry are in practice excluded. 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, included a diverse range of taxa, in at least 11 separate centres of origin. Wild grains were eaten from at least 105,000 years ago. From around 11,500 years ago, the eight Neolithic founder crops and einkorn wheat, hulled barley, lentils, bitter vetch, chick peas and flax were cultivated in the Levant. Rice was domesticated in China between 11,500 and 6,200 BC with the earliest known cultivation from 5,700 BC, followed by mung and azuki beans. Sheep were domesticated in Mesopotamia between 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, llamas 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, was independently domesticated in Eurasia. In Mesoamerica, wild teosinte was bred into maize by 6,000 years ago. 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. Wild stands, harvested started to be planted, came to be domesticated. In Eurasia, the Sumerians started to live in villages from about 8,000 BC, relying on the Tigris and Euphrates rivers and a canal system for irrigation. Ploughs appear in pictographs around 3,000 BC. Farmers grew wheat, vegetables such as lentils and onions, fruits including dates and figs.
Ancient Egyptian agriculture relied on its seasonal flooding. Farming started in the predynastic period at the end of the Paleolithic, after 10,000 BC. Staple food crops were grains such as wheat and barley, alongside industrial crops such as flax and papyrus. In India, wheat and jujube were domesticated by 9,000 BC, soon followed by sheep and goats. Cattle and goats were domesticated in Mehrgarh culture by 8,000–6,000 BC. Cotton was cultivated by the 5th-4th millennium BC. Archeological evidence indicates an animal-drawn plough from 2,500 BC in the Indus Valley Civilisation. In China, from the 5th century BC there was a nationwide granary system and widespread silk farming. Water-powered grain mills were in use followed by irrigation. By the late 2nd century, heavy ploughs had been developed with iron mouldboards; these spread westwards across Eurasia. Asian rice was domesticated 8,200–13,500 years ago – depending on the molecular clock estimate, used – on the Pearl River in southern China with a single genetic origin from the wild rice Oryza rufipogon