Domestic sheep are quadrupedal, ruminant mammals kept as livestock. Like most ruminants, sheep are members of the even-toed ungulates. Although the name sheep applies to many species in the genus Ovis, in everyday usage it always refers to Ovis aries. Numbering a little over one billion, domestic sheep are the most numerous species of sheep. An adult female sheep is referred to as a ewe, an intact male as a ram or a tup, a castrated male as a wether, a younger sheep as a lamb. Sheep are most descended from the wild mouflon of Europe and Asia. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleeces and milk. A sheep's wool is the most used animal fiber, is harvested by shearing. Ovine meat is called lamb when from younger animals and mutton when from older ones in Commonwealth countries, lamb in the United States. Sheep continue to be important for wool and meat today, are occasionally raised for pelts, as dairy animals, or as model organisms for science.
Sheep husbandry is practised throughout the majority of the inhabited world, has been fundamental to many civilizations. In the modern era, New Zealand, the southern and central South American nations, the British Isles are most associated with sheep production. Sheepraising has a large lexicon of unique terms which vary by region and dialect. Use of the word sheep began in Middle English as a derivation of the Old English word scēap. A group of sheep is called a herd or mob. Many other specific terms for the various life stages of sheep exist related to lambing and age. Being a key animal in the history of farming, sheep have a entrenched place in human culture, find representation in much modern language and symbology; as livestock, sheep are most associated with pastoral, Arcadian imagery. Sheep figure in many mythologies—such as the Golden Fleece—and major religions the Abrahamic traditions. In both ancient and modern religious ritual, sheep are used as sacrificial animals; the exact line of descent between domestic sheep and their wild ancestors is unclear.
The most common hypothesis states. Sheep were among the first animals to be domesticated by humankind. C in Mesopotamia; the rearing of sheep for secondary products, the resulting breed development, began in either southwest Asia or western Europe. Sheep were kept for meat and skins. Archaeological evidence from statuary found at sites in Iran suggests that selection for woolly sheep may have begun around 6000 BC, the earliest woven wool garments have been dated to two to three thousand years later. Sheep husbandry spread in Europe. Excavations show that in about 6000 BC, during the Neolithic period of prehistory, the Castelnovien people, living around Châteauneuf-les-Martigues near present-day Marseille in the south of France, were among the first in Europe to keep domestic sheep. From its inception, ancient Greek civilization relied on sheep as primary livestock, were said to name individual animals. Ancient Romans kept sheep on a wide scale, were an important agent in the spread of sheep raising.
Pliny the Elder, in his Natural History, speaks at length about wool. European colonists spread the practice to the New World from 1493 onwards. Domestic sheep are small ruminants with a crimped hair called wool and with horns forming a lateral spiral. Domestic sheep differ from their wild relatives and ancestors in several respects, having become uniquely neotenic as a result of selective breeding by humans. A few primitive breeds of sheep retain some of the characteristics of their wild cousins, such as short tails. Depending on breed, domestic sheep may have no horns at all, or horns in both sexes, or in males only. Most horned breeds have a single pair. Another trait unique to domestic sheep as compared to wild ovines is their wide variation in color. Wild sheep are variations of brown hues, variation within species is limited. Colors of domestic sheep range from pure white to dark chocolate brown, spotted or piebald. Selection for dyeable white fleeces began early in sheep domestication, as white wool is a dominant trait it spread quickly.
However, colored sheep do appear in many modern breeds, may appear as a recessive trait in white flocks. While white wool is desirable for large commercial markets, there is a niche market for colored fleeces for handspinning; the nature of the fleece varies among the breeds, from dense and crimped, to long and hairlike. There is variation of wool type and quality among members of the same flock, so wool classing is a step in the commercial processing of the fibre. Depending on breed, sheep show a range of weights, their rate of growth and mature weight is a heritable trait, selected for in breeding. Ewes weigh between 45 and 100 kilograms, rams between 45 and 160 kilograms; when all deciduous teeth have erupted, the sheep has 20 teeth. Mature sheep have 32 teeth; as with other ruminants, the front teeth in the lower jaw bite against a hard, toothless pad in the upper jaw. These are used to pick off vegetation the rear
A feral horse is a free-roaming horse of domesticated stock. As such, a feral horse is not a wild animal in the sense of an animal without domesticated ancestors. However, some populations of feral horses are managed as wildlife, these horses are popularly called "wild" horses. Feral horses are descended from domestic horses that strayed, escaped, or were deliberately released into the wild and remained to survive and reproduce there. Away from humans, over time, these animals' patterns of behavior revert to behavior more resembling that of wild horses; some horses that live in a feral state but may be handled or managed by humans if owned, are referred to as "semi-feral". Feral horses live in groups called a band, harem, or mob. Feral horse herds, like those of wild horses, are made up of small bands led by a dominant mare, containing additional mares, their foals, immature horses of both sexes. There is one herd stallion, though a few less-dominant males may remain with the group. Horse "herds" in the wild are best described as groups of several small bands who share a common territory.
Bands are on the small side, as few as three to five animals, but sometimes over a dozen. The makeup of bands shifts over time as young animals are driven out of the band they were born into and join other bands, or as young stallions challenge older males for dominance. However, in a given closed ecosystem, to maintain genetic diversity, the minimum size for a sustainable free-roaming horse or burro population is 150–200 animals. Horses which live in an untamed state but have ancestors who have been domesticated are not true "wild" horses. There are no known wild horses in existence today; the best-known examples of feral horses are the "wild" horses of the American west. When Europeans reintroduced the horse to the Americas, beginning with the arrival of the Conquistadors in the 15th century, some horses escaped and formed feral herds known today as Mustangs. Australia has the largest population of feral horses in the world, with in excess of 400,000 feral horses; the Australian name equivalent to the'Mustang' is the Brumby, feral descendants of horses brought to Australia by English settlers.
In Portugal, there are two populations of free-ranging feral horses, known as Sorraia in the southern plains and Garrano in the northern mountain chains. There are isolated populations of feral horses in a number of other places, including Sable Island off the coast of Nova Scotia, Assateague Island off the coast of Virginia and Maryland, Cumberland Island and Vieques island off the coast of Puerto Rico; some of these horses are said to be the descendants of horses who managed to swim to land when they were shipwrecked. Others may have been deliberately brought to various islands by settlers and either left to reproduce or abandoned when assorted human settlements failed. More than 400 feral horses live in the foothills of Cincar mountain, between Livno and Kupres and Herzegovina, in an area of 145 square kilometres; these animals, which descend from horses set free by their owners in the 1950s, enjoy a protected status since 2010. A modern feral horse population is found in the Dibru-Saikhowa National Park and Biosphere reserve of Assam, in north-east India, is a herd of 79 feral horses descended from animals that escaped army camps during World War II.
In North America, feral horses are descendants of horses that were domesticated in Europe, although many ancient, prehistoric subspecies now extinct did evolve in North America. While there are similarities shown in certain genes of both modern and fossil North American horses, they are not believed to be members of the same species. In the western United States, certain bands of horses and burros are protected under the Wild and Free-Roaming Horses and Burros Act of 1971. Modern types of feral horses that have a significant percentage of their number living in a feral state though there may be some domesticated representatives, include the following types and breeds: Alberta Mountain Horse or Alberta "Wildie", found in the foothills of the Eastern Slopes of the Rocky Mountains of Alberta, Canada Banker horse, on the Outer Banks of North Carolina Brumby, the feral horse of Australia Chincoteague Pony, on Assateague Island off the coasts of Virginia and Maryland Cumberland Island horse, on Cumberland Island off the coast of southern Georgia Danube Delta horse, in and around Letea Forest, between the Sulina and Chilia branches of the Danube Elegesi Qiyus Wild Horse, Canada.
Sorraia, a feral horse native to southern Portugal Sable Island Horse found on an island off the coast of Nova Scotia Welsh Pony domesticated, but a feral population of about 180 animals roams the Carneddau hills of North Wales. Other populations roam the eastern parts of the Brecon Beacons National Park. Delft Island Feral Horses are believed to be the descendants of horses kept on the island from the time of De
Australian feral camel
Australian feral camels are feral populations consisting of two species of camel: dromedaries but some Bactrian camels. Imported into Australia from British India and Afghanistan during the 19th century for transport and construction during the colonisation of the central and western parts of Australia, many were released into the wild after motorised transport replaced the use of camels in the early 20th century, resulting in a fast-growing feral population. By 2008, it was feared that Central Australia's feral camel population had grown to about one million and was projected to double every 8 to 10 years. Camels are known to cause serious degradation of local environmental and cultural sites during dry conditions. An AU$19 million management program was funded in 2009, upon completion in 2013, the feral population was estimated to have been reduced to around 300,000. Camels had been used in desert exploration in other parts of the world; the first suggestion of importing camels into Australia was made in 1822 by Danish-French geographer and journalist Conrad Malte-Brun, whose Universal Geography contains the following.
They ought to be provided with all sorts of implements and stores, with different animals, from the powers and instincts of which they may derive assistance. They should have oxen from Buenos Aires, or from the English settlements, mules from Senegal, dromedaries from Africa or Arabia; the oxen would traverse the thickets. Thus the expedition would be prepared for any kind of territory. Dogs should be taken to raise game, to discover springs of water; when no kangaroos and game are to be found the party would subsist on the flesh of their own flocks. They should be provided with a balloon for spying at a distance any serious obstacle to their progress in particular directions, for extending the range of observations which the eye would take of such level lands as are too wide to allow any heights beyond them to come within the compass of their view. In 1839, Lieutenant-Colonel George Gawler, second Governor of South Australia, suggested that camels should be imported to work in the semi-arid regions of Australia.
The first camel arrived in Australia in 1840, ordered from the Canary Islands by the Phillips brothers of Adelaide. The Apolline, under Captain William Deane, docked at Port Adelaide in South Australia on 12 October 1840, but all but one of the camels died on the voyage; the surviving camel was named Harry. This camel, was used for inland exploration by pastoralist and explorer John Ainsworth Horrocks on his ill-fated 1846 expedition into the arid South Australian interior near Lake Torrens, in searching for new agricultural land, he became known as the'man, shot by his own camel'. On 1 September Horrocks was preparing to shoot a bird on the shores of Lake Dutton, his kneeling camel moved while Horrocks was reloading his gun, fatally injuring Horrocks by injuring the middle fingers of his right hand and a row of teeth. Horrocks died of his wounds on 23 September in Penwortham after requesting. Australia's first major inland expedition to use camels as a main form of transport was the Burke and Wills expedition in 1860.
The Victorian Government imported 24 camels for the expedition. The first Muslim cameleers arrived on 9 June 1860 at Port Melbourne from Kurrachee on the ship the Chinsurah, to participate in the Burke and Wills expedition; as described by the Victorian Exploration Expedition Committee, "the camels would be comparatively useless unless accompanied by their native drivers". The cameleers on the expedition included 45-year-old Dost Mahomed, bitten by a bull camel losing permanent use of his right arm, Esa Khan from Kalat, who fell ill near Swan Hill, they cared for the camels and unloaded equipment and provisions and located water on the expedition. From the 1860s onward small groups of cameleers were shipped in and out of Australia at three-year intervals, to service South Australia's inland pastoral industry. Carting goods and transporting wool bales by camel was a lucrative livelihood for them; as their knowledge of the Australian outback and economy increased, Muslim cameleers began their own businesses and running camel trains.
By 1890 the camel business was dominated by Muslim merchants and brokers referred to as "Afghans" or "Ghans", despite their origin being British India as well as Afghanistan. They belonged to four main groups: Pashtuns, Baluchis and Sindhis. At least 15,000 camels with their handlers are estimated to have come to Australia between 1870 and 1900. Most of these camels were dromedaries from India, including the Bikaneri war camel from Rajasthan as a riding camel, lowland Indian camels for heavy work. Other dromedaries included the Bishari riding camel of North Arabia. A bull camel could be expected to carry up to 600 kilograms, camel strings could cover more than 25 miles per day. Camel studs were set up in 1866, by Sir Thomas Elder and Samuel Stuckey, at Beltana and Umberatana Stations in South Australia. There was a government stud camel farm at Londonderry, near Coolgardie in Western Australia, established in 1894; these studs operated for about 50 years and provided high-class breeders for the Australian camel trade.
Cornwall is a county in South West England in the United Kingdom. The county is bordered to the north and west by the Celtic Sea, to the south by the English Channel, to the east by the county of Devon, over the River Tamar which forms most of the border between them. Cornwall forms the westernmost part of the South West Peninsula of the island of Great Britain; the furthest southwestern point of Great Britain is Land's End. Cornwall has a population of 563,600 and covers an area of 3,563 km2; the county has been administered since 2009 by Cornwall Council. The ceremonial county of Cornwall includes the Isles of Scilly, which are administered separately; the administrative centre of Cornwall, its only city, is Truro. Cornwall is the homeland of the Cornish people and the cultural and ethnic origin of the Cornish diaspora, it retains a distinct cultural identity that reflects its history, is recognised as one of the Celtic nations. It was a Brythonic kingdom and subsequently a royal duchy; the Cornish nationalist movement contests the present constitutional status of Cornwall and seeks greater autonomy within the United Kingdom in the form of a devolved legislative Cornish Assembly with powers similar to those in Wales and Scotland.
In 2014, Cornish people were granted minority status under the European Framework Convention for the Protection of National Minorities, giving them recognition as a distinct ethnic group. First inhabited in the Palaeolithic and Mesolithic periods, Cornwall continued to be occupied by Neolithic and Bronze Age peoples, by Brythons with strong ethnic, linguistic and cultural links to Wales and Brittany the latter of, settled by Britons from the region. Mining in Cornwall and Devon in the south-west of England began in the early Bronze Age. Few Roman remains have been found in Cornwall, there is little evidence that the Romans settled or had much military presence there. After the collapse of the Roman Empire, Cornwall was a part of the Brittonic kingdom of Dumnonia, ruled by chieftains of the Cornovii who may have included figures regarded as semi-historical or legendary, such as King Mark of Cornwall and King Arthur, evidenced by folklore traditions derived from the Historia Regum Britanniae.
The Cornovii division of the Dumnonii tribe were separated from their fellow Brythons of Wales after the Battle of Deorham in 577 AD, came into conflict with the expanding English kingdom of Wessex. The regions of Dumnonia outside of Cornwall had been annexed by the English by 838 AD. King Athelstan in 936 AD set the boundary between the English and Cornish at the high water mark of the eastern bank of the River Tamar. From the early Middle Ages and culture were shared by Brythons trading across both sides of the Channel, resulting in the corresponding high medieval Breton kingdoms of Domnonée and Cornouaille and the Celtic Christianity common to both areas. Tin mining was important in the Cornish economy. In the mid-19th century, the tin and copper mines entered a period of decline. Subsequently, china clay extraction became more important, metal mining had ended by the 1990s. Traditionally and agriculture were the other important sectors of the economy. Railways led to a growth of tourism in the 20th century.
Cornwall is noted for coastal scenery. A large part of the Cornubian batholith is within Cornwall; the north coast has many cliffs. The area is noted for its wild moorland landscapes, its long and varied coastline, its attractive villages, its many place-names derived from the Cornish language, its mild climate. Extensive stretches of Cornwall's coastline, Bodmin Moor, are protected as an Area of Outstanding Natural Beauty; the modern English name Cornwall is a compound of two ancient demonyms coming from two different language groups: Corn- originates from the Brythonic tribe, the Cornovii. The Celtic word "kernou" is cognate with the English word "horn". -wall derives from the Old English exonym walh, meaning "foreigner" or "Roman". In the Cornish language, Cornwall is known as Kernow which stems from a similar linguistic background; the present human history of Cornwall begins with the reoccupation of Britain after the last Ice Age. The area now known as Cornwall was first inhabited in the Mesolithic periods.
It continued to be occupied by Neolithic and Bronze Age people. According to John T. Koch and others, Cornwall in the Late Bronze Age was part of a maritime trading-networked culture called the Atlantic Bronze Age, in modern-day Ireland, Wales, France and Portugal. During the British Iron Age, like all of Britain, was inhabited by a Celtic people known as the Britons with distinctive cultural relations to neighbouring Brittany; the Common Brittonic spoken at the time developed into several distinct tongues, including Cornish, Breton and Pictish. The first account of Cornwall comes from the 1st-century BC Sicilian Greek historian Diodorus Siculus quoting or paraphrasing the 4th-century BCE geographer P
The feral pig is a pig living in the wild, but which has descended from escaped domesticated individuals in both the Old and New Worlds. Razorback and wild hog are American colloquialisms, loosely applied to any type of feral domestic pig, wild boar, or hybrid in North America; the term "razorback" has appeared in Australia, to describe feral pigs there. A feral pig is a domestic pig that has escaped or been released into the wild, is living more or less as a wild animal. Zoologists exclude from the feral category animals that, although captive, were genuinely wild before they escaped. Accordingly, Eurasian wild boar, released or escaped into habitats where they are not native, such as in North America, are not considered feral, although they may interbreed with feral pigs. Reintroduced wild boars in Western Europe are not considered feral, despite the fact that they were raised in captivity prior to their release; the natural habitats of wild boar are woodlands. In the UK, wild boar can be farmed under licence.
However, to release them into the wild is illegal. Established populations of wild boar occur in the Forest of Gloucestershire; these are active during the daytime and are less wary of people. This is in contrast to populations in East Sussex, which are wary of people. Groups of wild boar have been reported in the Scottish Highlands including Invermoriston, near Loch Ness, between Newtonmore and Laggan. A group believed to be a mix of wild boar and domestic pig that escaped from a farm, have been seen in the Strathnairn area near Inverness. Wild boar occur elsewhere in the UK according to the Department for Environment and Rural Affairs, it said between 100 and 200 were estimated to be in Kent and East Sussex, about 20–30 in West Dorset. The practice of introducing domestic pigs into the New World persisted throughout the exploration periods of the 16th and 17th centuries; the Eurasian wild boar, which ranged from Great Britain to European Russia, may have been introduced. By the 19th century, their numbers were sufficient in some areas such as the Southern United States to become a common game animal.
Feral pigs are a growing problem in the United States. As of 2013, the estimated population of 6 million feral pigs causes billions of dollars in property and agricultural damage every year in the United States, both in wild and agricultural lands; because pigs forage by rooting for their food under the ground with their snouts and tusks, a sounder of feral pigs can damage acres of planted fields in just a few nights. Because of the feral pig's omnivorous nature, it is a danger to both plants and animals endemic to the area it is invading. Game animals such as deer and turkeys, more flora such as the Opuntia plant have been affected by the feral hog's aggressive competition for resources. Feral pigs have been determined to be potential hosts for at least 34 pathogens that can be transmitted to livestock and humans. For commercial pig farmers, great concern exists that some of the hogs could be a vector for swine fever to return to the US, extinct in America since 1978. Feral pigs could present an immediate threat to "nonbiosecure" domestic pig facilities because of their likeliness to harbor and spread pathogens the protozoan Sarcocystis.
By the early 2000s, the range of feral pigs included all of the US south of 36°N. The range begins in the mountains surrounding California and crosses over the mountains, continuing much farther east towards the Louisiana bayous and forests, terminating in the entire Florida peninsula. In the East, the range expands northward to include most of the forested areas and swamps of the Southeast, from there goes north along the Appalachian Mountains as far as upstate New York, with a growing presence in states bordering West Virginia and Kentucky. Texas has the largest estimated population of 2.6 million feral pigs existing in 253 of its 254 counties. Outside mainland US, Hawaii has feral pigs introduced to Oahu soon after Captain Cook's discovery of Hawaii in 1778, where they prey on or eat endangered birds and plants; the population of feral pigs has increased from two million pigs ranging over 20 states in 1990, to triple that number 25 years ranging over 38 states with new territories expanding north into Oregon, Pennsylvania and New Hampshire.
Some of these feral pigs have mixed with escaped Russian boar, introduced for hunters from the early 1990s. Because feral pigs are omnivorous, their feeding behaviour disrupts the entire food chain. Plants have difficulties regenerating from their wallowing, as North American flora did not evolve to withstand the destruction caused by rooting pigs, unlike Europe or Asia. Feral pigs in the US eat small animals such as wild turkey poults, toads and the eggs of reptiles and birds; this can deprive other wildlife that would feed upon these important food sources. In some case, other wildlife are outcompeted by the feral pigs' higher reproductive rate. In the autumn, other animals such as the American black bear compete directly with feral pigs as both forage for tree mast. In the US, the problems caused by feral pigs ar
Mammals are vertebrate animals constituting the class Mammalia, characterized by the presence of mammary glands which in females produce milk for feeding their young, a neocortex, fur or hair, three middle ear bones. These characteristics distinguish them from reptiles and birds, from which they diverged in the late Triassic, 201–227 million years ago. There are around 5,450 species of mammals; the largest orders are the rodents and Soricomorpha. The next three are the Primates, the Cetartiodactyla, the Carnivora. In cladistics, which reflect evolution, mammals are classified as endothermic amniotes, they are the only living Synapsida. The early synapsid mammalian ancestors were sphenacodont pelycosaurs, a group that produced the non-mammalian Dimetrodon. At the end of the Carboniferous period around 300 million years ago, this group diverged from the sauropsid line that led to today's reptiles and birds; the line following the stem group Sphenacodontia split off several diverse groups of non-mammalian synapsids—sometimes referred to as mammal-like reptiles—before giving rise to the proto-mammals in the early Mesozoic era.
The modern mammalian orders arose in the Paleogene and Neogene periods of the Cenozoic era, after the extinction of non-avian dinosaurs, have been among the dominant terrestrial animal groups from 66 million years ago to the present. The basic body type is quadruped, most mammals use their four extremities for terrestrial locomotion. Mammals range in size from the 30–40 mm bumblebee bat to the 30-meter blue whale—the largest animal on the planet. Maximum lifespan varies from two years for the shrew to 211 years for the bowhead whale. All modern mammals give birth to live young, except the five species of monotremes, which are egg-laying mammals; the most species-rich group of mammals, the cohort called placentals, have a placenta, which enables the feeding of the fetus during gestation. Most mammals are intelligent, with some possessing large brains, self-awareness, tool use. Mammals can communicate and vocalize in several different ways, including the production of ultrasound, scent-marking, alarm signals and echolocation.
Mammals can organize themselves into fission-fusion societies and hierarchies—but can be solitary and territorial. Most mammals are polygynous. Domestication of many types of mammals by humans played a major role in the Neolithic revolution, resulted in farming replacing hunting and gathering as the primary source of food for humans; this led to a major restructuring of human societies from nomadic to sedentary, with more co-operation among larger and larger groups, the development of the first civilizations. Domesticated mammals provided, continue to provide, power for transport and agriculture, as well as food and leather. Mammals are hunted and raced for sport, are used as model organisms in science. Mammals have been depicted in art since Palaeolithic times, appear in literature, film and religion. Decline in numbers and extinction of many mammals is driven by human poaching and habitat destruction deforestation. Mammal classification has been through several iterations since Carl Linnaeus defined the class.
No classification system is universally accepted. George Gaylord Simpson's "Principles of Classification and a Classification of Mammals" provides systematics of mammal origins and relationships that were universally taught until the end of the 20th century. Since Simpson's classification, the paleontological record has been recalibrated, the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself through the new concept of cladistics. Though field work made Simpson's classification outdated, it remains the closest thing to an official classification of mammals. Most mammals, including the six most species-rich orders, belong to the placental group; the three largest orders in numbers of species are Rodentia: mice, porcupines, beavers and other gnawing mammals. The next three biggest orders, depending on the biological classification scheme used, are the Primates including the apes and lemurs. According to Mammal Species of the World, 5,416 species were identified in 2006.
These were grouped into 153 families and 29 orders. In 2008, the International Union for Conservation of Nature completed a five-year Global Mammal Assessment for its IUCN Red List, which counted 5,488 species. According to a research published in the Journal of Mammalogy in 2018, the number of recognized mammal species is 6,495 species included 96 extinct; the word "mammal" is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from the Latin mamma. In an influential 1988 paper, Timothy Rowe defined Mammalia phylogenetically as the crown group of mammals, the clade consisting of the most recent common ancestor of living monotremes and therian m
Domestication is a sustained multi-generational relationship in which one group of organisms assumes a significant degree of influence over the reproduction and care of another group to secure a more predictable supply of resources from that second group. Charles Darwin recognized the small number of traits that made domestic species different from their wild ancestors, he was the first to recognize the difference between conscious selective breeding in which humans directly select for desirable traits, unconscious selection where traits evolve as a by-product of natural selection or from selection on other traits. There is a genetic difference between wild populations. There is such a difference between the domestication traits that researchers believe to have been essential at the early stages of domestication, the improvement traits that have appeared since the split between wild and domestic populations. Domestication traits are fixed within all domesticates, were selected during the initial episode of domestication of that animal or plant, whereas improvement traits are present only in a proportion of domesticates, though they may be fixed in individual breeds or regional populations.
The dog was the first domesticated vertebrate, was established across Eurasia before the end of the Late Pleistocene era, well before cultivation and before the domestication of other animals. The archaeological and genetic data suggest that long-term bidirectional gene flow between wild and domestic stocks – including donkeys, horses and Old World camelids, goats and pigs – was common. Given its importance to humans and its value as a model of evolutionary and demographic change, domestication has attracted scientists from archaeology, anthropology, zoology and the environmental sciences. Among birds, the major domestic species today is the chicken, important for meat and eggs, though economically valuable poultry include the turkey and numerous other species. Birds are widely kept as cagebirds, from songbirds to parrots; the longest established invertebrate domesticates are the silkworm. Terrestrial snails are raised for food, while species from several phyla are kept for research, others are bred for biological control.
The domestication of plants began at least 12,000 years ago with cereals in the Middle East, the bottle gourd in Asia. Agriculture developed in at least 11 different centres around the world, domesticating different crops and animals. Domestication, from the Latin domesticus,'belonging to the house', is "a sustained multi-generational, mutualistic relationship in which one organism assumes a significant degree of influence over the reproduction and care of another organism in order to secure a more predictable supply of a resource of interest, through which the partner organism gains advantage over individuals that remain outside this relationship, thereby benefitting and increasing the fitness of both the domesticator and the target domesticate." This definition recognizes both the biological and the cultural components of the domestication process and the impacts on both humans and the domesticated animals and plants. All past definitions of domestication have included a relationship between humans with plants and animals, but their differences lay in, considered as the lead partner in the relationship.
This new definition recognizes a mutualistic relationship. Domestication has vastly enhanced the reproductive output of crop plants and pets far beyond that of their wild progenitors. Domesticates have provided humans with resources that they could more predictably and securely control and redistribute, the advantage that had fueled a population explosion of the agro-pastoralists and their spread to all corners of the planet. Houseplants and ornamentals are plants domesticated for aesthetic enjoyment in and around the home, while those domesticated for large-scale food production are called crops. Domesticated plants deliberately altered or selected for special desirable characteristics are cultigens. Animals domesticated for home companionship are called pets, while those domesticated for food or work are known as livestock; this biological mutualism is not restricted to humans with domestic crops and livestock but is well-documented in nonhuman species among a number of social insect domesticators and their plant and animal domesticates, for example the ant–fungus mutualism that exists between leafcutter ants and certain fungi.
Domestication syndrome is the suite of phenotypic traits arising during domestication that distinguish crops from their wild ancestors. The term is applied to vertebrate animals, includes increased docility and tameness, coat color changes, reductions in tooth size, changes in craniofacial morphology, alterations in ear and tail form, more frequent and nonseasonal estrus cycles, alterations in adrenocorticotropic hormone levels, changed concentrations of several neurotransmitters, prolongations in juvenile behavior, reductions in both total brain size and of particular brain regions; the domestication of animals and plants began with the wolf at least 15,000 years before present, which led to a rapid shift in the evolution and demography of both humans and numerous species of animals and plants. The sudden appearance of the domestic dog in the archaeological record was followed by livestock and crop domestication, the transition of humans from foraging to farming in different places and times across the planet.
Around 10,000 YBP, a new way of life emerged for humans through the management and exploitation of plant and an