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81-572: Poephagus grunniens The yak ( Bos grunniens ), also known as the Tartary ox , grunting ox , hairy cattle , or domestic yak , is a species of long-haired domesticated cattle found throughout the Himalayan region of Gilgit-Baltistan ( Kashmir , Pakistan ), Nepal , Sikkim ( India ), the Tibetan Plateau ( China ), Tajikistan and as far north as Mongolia and Siberia . It

162-420: A "broad" definition: "a coevolutionary process that arises from a mutualism, in which one species (the domesticator) constructs an environment where it actively manages both the survival and reproduction of another species (the domesticate) in order to provide the former with resources and/or services." He comments that this adds niche construction to the activities of the domesticator. Domestication syndrome

243-860: A few have been domesticated, including squid , cuttlefish and octopus , all used in research on behaviour and neurology . Terrestrial snails in the genera Helix are raised for food. Several parasitic or parasitoidal insects, including the fly Eucelatoria , the beetle Chrysolina , and the wasp Aphytis are raised for biological control. Conscious or unconscious artificial selection has many effects on species under domestication; variability can readily be lost by inbreeding, selection against undesired traits, or genetic drift, while in Drosophila , variability in eclosion time (when adults emerge) has increased. Humans foraged for wild cereals, seeds, and nuts thousands of years before they were domesticated; wild wheat and barley, for example, were gathered in

324-484: A means of communication between far-flung places through the exploitation of the pigeon's homing instinct; research suggests it was domesticated as early as 10,000 years ago. Chicken fossils in China have been dated to 7,400 years ago. The chicken's wild ancestor is Gallus gallus , the red junglefowl of Southeast Asia. The species appears to have been kept initially for cockfighting rather than for food. Two insects ,

405-1088: A mixture of both taurine and zebu types of cattle ( B. p. taurus and B. p. indicus ) with yak. According to the International Veterinary Information Service , the low productivity of second-generation cattle–yak crosses makes them suitable only as meat animals. Crosses between yaks and domestic cattle ( Bos primigenius taurus ) have been recorded in Chinese literature for at least 2,000 years. Successful crosses have also been recorded between yak and American bison , gaur , and banteng , generally with similar results to those produced with domestic cattle. Jacques et al. (2021) show that most elaborate yak-related terminologies are found within Tibetic and Gyalrongic languages. Both branches also have native terms for yak-cattle hybrids , suggesting that Tibetic and Gyalrongic speakers may have independently cross-bred yaks and cattle, predating

486-468: A population bottleneck where genetic drift is enhanced by the small population size. Mutations can also be fixed in a population by a selective sweep . Mutational load can be increased by reduced selective pressure against moderately harmful traits when reproductive fitness is controlled by human management. However, there is evidence against a bottleneck in crops, such as barley, maize, and sorghum, where genetic diversity slowly declined rather than showing

567-779: A predictable supply of a resource, resulting in mutual benefits . She noted further that it is not synonymous with agriculture since agriculture depends on domesticated organisms but does not automatically result from domestication. Michael D. Purugganan notes that domestication has been hard to define, despite the "instinctual consensus" that it means "the plants and animals found under the care of humans that provide us with benefits and which have evolved under our control." He comments that insects such as termites , ambrosia beetles , and leafcutter ants have domesticated some species of fungi , and notes further that other groups such as weeds and commensals have wrongly been called domesticated. Starting from Zeder's definition, Purugganan proposes

648-425: A protracted coevolutionary process with multiple stages along different pathways. There are three proposed major pathways that most mammal domesticates followed into domestication: Humans did not intend to domesticate mammals from either the commensal or prey pathways, or at least they did not envision a domesticated animal would result from it. In both of those cases, humans became entangled with these species as

729-575: A rapid initial fall at the point of domestication. Further, the genetic diversity of these crops was regularly replenished from the natural population. Similar evidence exists for horses, pigs, cows, and goats. At least three groups of insects, namely ambrosia beetles, leafcutter ants, and fungus-growing termites, have domesticated species of fungi . Ambrosia beetles in the weevil subfamilies Scolytinae and Platypodinae excavate tunnels in dead or stressed trees into which they introduce fungal gardens, their sole source of nutrition. After landing on

810-490: A result, most roan cows exhibit blotches of clearly colored and clearly white hair, with roan patches. Some "cryptic" roan cattle appear solid, but upon close inspection reveal a small roan patch. Roan cattle cannot "breed true" but breeding white cattle to a solid mate will always yield a roan calf. The white color typical of Charolais and White Park breeds is not related to roan. Roan in Shorthorns and Belgian Blues

891-457: A roughly even mixture of white regions and colored regions. The reproductive condition "White Heifer Disease," associated with the MGF gene, is characterized by homozygous MGF-white heifers with incomplete reproductive tracts. The roan coloration of guinea pigs is linked to microphthalmia . The allele that controls roaning in guinea pigs is incompletely dominant : an animal with one copy of

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972-457: A steady supply of resources, such as meat, milk, or labor. The process is gradual and geographically diffuse, based on trial and error. 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 cereal seedheads. Such changes both make domesticated organisms easier to handle and reduce their ability to survive in

1053-402: A suitable tree, an ambrosia beetle excavates a tunnel in which it releases its fungal symbiont . The fungus penetrates the plant's xylem tissue, extracts nutrients from it, and concentrates the nutrients on and near the surface of the beetle gallery. Ambrosia fungi are typically poor wood degraders and instead utilize less demanding nutrients. Symbiotic fungi produce and detoxify ethanol, which

1134-474: 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 . Beginning around 10,000 years ago, Indigenous peoples in

1215-456: Is actually one of the leopard complex coat patterns associated with Appaloosa , Knabstrupper , Noriker horse and related breeds. Rabicano is a white pattern that falls into the category of roaning or scattered white hairs, the genetics of which are not yet fully understood. Sometimes called ticking , rabicano is common even in breeds that do not have true or classic roan, including Arabians and Thoroughbreds . This pattern usually takes

1296-405: Is an attractant for ambrosia beetles and likely prevents the growth of antagonistic pathogens and selects for other beneficial symbionts. Ambrosia beetles mainly colonise wood of recently dead trees. The leafcutter ants are any of some 47 species of leaf-chewing ants in the genera Acromyrmex and Atta . The ants carry the discs of leaves that they have cut back to their nest, where they feed

1377-666: Is controlled by the mast cell growth factor (MGF) gene , also called the steel locus , on bovine chromosome 5. Part of the KIT ligand , this region is involved in many cell differentiation processes . Mast cell growth factor promotes pigment production by pigment cells , and without it, skin and hair cells lack pigment. With two functional MGF genes ( homozygous dominant), cattle are fully pigmented; without any functional MGF genes (homozygous recessive ), they are white. MGF-controlled roan occurs when cattle possess one functional and one non-functional MGF gene ( heterozygous ), resulting in

1458-624: Is descended from the wild yak ( Bos mutus ). The English word yak originates from the Tibetan : གཡག་ , Wylie : g.yag . In Tibetan and Balti it refers only to the male of the species, the female being called Tibetan : འབྲི་ , Wylie : dri , Tibetan : འབྲི་ , Wylie : dri or Tibetan : གནག , Wylie : g.nag in Tibetan and Tibetan : ཧཡག་མོ་ , Wylie : hYag-mo in Balti. In English, as in most other languages that have borrowed

1539-440: Is described in many breeds of gundogs such as English Cocker Spaniels , American Cocker Spaniels , English Springer Spaniels , Field Spaniels and Brittanys , German Longhaired Pointers , German Shorthaired Pointers , Bracchi Italiani , Spinoni Italiani , Lagotti Romagnoli , English Setters , Small Münsterländer as well as Border Collies and many other breeds. In dogs, roan manifests itself only in unpigmented areas,

1620-432: Is domesticated wheat, which relies on farmers for its reproduction and dissemination. Domesticated plants differ from their wild relatives in many ways, including Plant defenses against herbivory , such as thorns, spines, and prickles , poison, protective coverings, and sturdiness may have been reduced in domesticated plants. This would make them more likely to be eaten by herbivores unless protected by humans, but there

1701-622: Is held to drink the fresh blood of yak, and it is believed that it cures various diseases such as gastritis, jaundice , and body strain. The fresh blood is extracted from the neck of a yak without killing it. The cut is healed after the ceremony is over. The ritual is believed to be originated in Tibet and Mustang . 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, to obtain from them

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1782-685: Is likely that this may be somewhat shorter in the wild. For thousands of years, domesticated yaks have been kept in Mongolia and Tibet, primarily for their milk, fibre (wool), and meat, and as beasts of burden . Their dried droppings are an important fuel, used all over Tibet, and are often the only fuel available on the high, treeless Tibetan Plateau . Yaks transport goods across mountain passes for local farmers and traders and are an attraction for climbing and trekking expeditions: "Only one thing makes it hard to use yaks for long journeys in barren regions. They will not eat grain , which could be carried on

1863-629: Is located at Dirang , Arunachal Pradesh , and maintains a yak farm in the Nyukmadung area at an altitude of 2,750 metres (9,020 ft) above MSL. In Nepal , Tibet , and Mongolia , domestic cattle are crossbred with yaks. This gives rise to the infertile male dzo མཛོ། as well as fertile females known as dzomo or zhom མཛོ་མོ།, which may be crossed again with cattle. The Dwarf Lulu breed, "the only Bos primigenius taurus type of cattle in Nepal" has been tested for DNA markers and found to be

1944-427: Is nearly completely white, may be confused with roans when they are young. Duns , which are solid-colored horses affected by the dun dilution factor on their bodies but with darker points, are also sometimes confused with roans, but they do not have the intermixed white and colored hairs of a roan. Horses with the classic or true roan pattern may be any base color which is intermingled with unpigmented white hairs on

2025-669: Is only weak support for most of this. Farmers did select for reduced bitterness and lower toxicity and for food quality, which likely increased crop palatability to herbivores as to humans. However, a survey of 29 plant domestications found that crops were as well-defended against two major insect pests ( beet armyworm and green peach aphid ) both chemically (e.g. with bitter substances) and morphologically (e.g. with toughness) as their wild ancestors. During domestication, crop species undergo intense artificial selection that alters their genomes, establishing core traits that define them as domesticated, such as increased grain size. Comparison of

2106-668: Is the suite of phenotypic traits that arose during the initial domestication process and which distinguish crops from their wild ancestors . It can also mean a set of differences now observed in domesticated mammals, not necessarily reflecting the initial domestication process. The changes include increased docility and tameness, coat coloration, reductions in tooth size, craniofacial morphology, ear and tail form (e.g., floppy ears), estrus cycles, levels of adrenocorticotropic hormone and neurotransmitters, prolongations in juvenile behavior, and reductions in brain size and of particular brain regions. The domestication of animals and plants

2187-725: Is today Baluchistan in Pakistan. In East Asia 8,000 years ago, pigs were domesticated from wild boar genetically different from those found in the Fertile Crescent. The cat was domesticated in the Fertile Crescent, perhaps 10,000 years ago, from European wildcats , possibly to control rodents that were damaging stored food. The domestication of vertebrate animals is the relationship between non-human vertebrates and humans who have an influence on their care and reproduction. In his 1868 book The Variation of Animals and Plants Under Domestication , Charles Darwin recognized

2268-636: Is widely grown for food. The yeast Saccharomyces cerevisiae have been used for thousands of years to ferment beer and wine , and to leaven bread . Mould fungi including Penicillium are used to mature cheeses and other dairy products, as well as to make drugs such as antibiotics . Selection of animals for visible traits may have undesired consequences for the genetics of domestic animals. A side effect of domestication has been zoonotic diseases. For example, cattle have given humanity various viral poxes , measles , and tuberculosis ; pigs and ducks have contributed influenza ; and horses have brought

2349-718: The Indian Ocean and those in the Pacific Ocean . The coconut experienced a founder effect , where a small number of individuals with low diversity founded the modern population, permanently losing much of the genetic variation of the wild population. Population bottlenecks which reduced variation throughout the genome at some later date after domestication are evident in crops such as pearl millet , cotton , common bean and lima bean . In wheat, domestication involved repeated hybridization and polyploidy . These steps are large and essentially instantaneous changes to

2430-634: The Levant at least 23,000 years ago. Neolithic societies in West Asia first began to cultivate and then domesticate some of these plants around 13,000 to 11,000 years ago. The founder crops of the West Asian Neolithic included cereals ( emmer , einkorn wheat , barley ), pulses ( lentil , pea , chickpea , bitter vetch ), and flax . Other plants were independently domesticated in 13 centers of origin (subdivided into 24 areas) of

2511-619: The coding DNA of chromosome 8 in rice between fragrant and non-fragrant varieties showed that aromatic and fragrant rice, including basmati and jasmine , is derived from an ancestral rice domesticate that suffered a deletion in exon 7 which altered the coding for betaine aldehyde dehydrogenase (BADH2). Comparison of the potato genome with that of other plants located genes for resistance to potato blight caused by Phytophthora infestans . In coconut , genomic analysis of 10 microsatellite loci (of noncoding DNA ) found two episodes of domestication based on differences between individuals in

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2592-470: The domestication of wheat . Wild wheat shatters and falls to the ground to reseed itself when ripe, but domesticated wheat stays on the stem for easier harvesting. This change was possible because of a random mutation in the wild populations at the beginning of wheat's cultivation . Wheat with this mutation was harvested more frequently and became the seed for the next crop. Therefore, without realizing it, early farmers selected for this mutation. The result

2673-417: The domestication syndrome , traits presumed essential in the early stages of domestication, while others represent later improvement traits. Domesticated mammals in particular tend to be smaller and less aggressive than their wild counterparts; other common traits are floppy ears, a smaller brain, and a shorter muzzle. Domestication traits are generally fixed within all domesticates, and were selected during

2754-404: The omasum . This likely allows them to consume greater quantities of low-quality food at a time, and to ferment it longer to extract more nutrients. Yak consume the equivalent of 1% of their body weight daily while cattle require 3% to maintain condition. They are grazing herbivores, with their wild ancestors feeding primarily on grass and sedges , with some herbs and dwarf shrubs. Yaks mate in

2835-437: The rhinoviruses . Many parasites , too, have their origins in domestic animals. Alongside these, the advent of domestication resulted in denser human populations, which provided ripe conditions for pathogens to reproduce, mutate, spread, and eventually find a new host in humans. Scholars have expressed widely differing viewpoints on domestication's effects on society. Anarcho-primitivism critiques domestication as destroying

2916-436: The silkworm and the western honey bee , have been domesticated for over 5,000 years, often for commercial use. The silkworm is raised for the silk threads wound around its pupal cocoon; the western honey bee, for honey , and, from the 20th century, for pollination of crops. Several other invertebrates have been domesticated, both terrestrial and aquatic, including some such as Drosophila melanogaster fruit flies and

2997-555: The Americas began to cultivate peanuts , squash , maize , potatoes , cotton , and cassava . Rice was first domesticated in China some about 9,000 years ago. In Africa, crops such as sorghum were domesticated. Agriculture developed in some 13 centres around the world, domesticating different crops and animals. Three groups of insects, namely ambrosia beetles , leafcutter ants , and fungus-growing termites have independently domesticated species of fungi, on which they feed. In

3078-592: The Americas, Africa, and Asia (the Middle East, South Asia, the Far East, and New Guinea and Wallacea); in some thirteen of these regions people began to cultivate grasses and grains. Rice was first cultivated in East Asia. Sorghum was widely cultivated in sub-Saharan Africa, while peanuts, squash, cotton, maize , potatoes , and cassava were domesticated in the Americas. Continued domestication

3159-458: The KIT sequence. The overall effect is that of a silver or lightened appearance to the affected part of the coat. Descriptions of roan coat colors are as follows: Any other coat color may also be affected by roaning. Few combinations have the same unique terminology applied to the common roan colors, although palomino roans are sometimes called honey roans . A varnish roan is not a true roan; it

3240-473: The Large Munsterlander, clear white-marked individuals may be called plated . The term belton is reserved for English Setters . In 1957, Little suggested that roan and ticking were controlled separately, and postulated that roan may have been homologous to "silvered" coat in mice. This condition in mice is actually homologous to merle , which might be described by some as "roan." In 2007,

3321-595: The Late Pleistocene. Domestication reduces genetic diversity of the domesticated population, especially of alleles of genes targeted by selection. One reason is a population bottleneck created by artificially selecting the most desirable individuals to breed from. Most of the domesticated strain is then born from just a few ancestors, creating a situation similar to the founder effect . Domesticated populations such as of dogs, rice, sunflowers, maize, and horses have an increased mutation load , as expected in

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3402-649: The United States, Canada, New Zealand, and some parts of Europe. Yaks have generated interest outside the Himalayas as a commercial crop and by cattle breeders. The main interest of North American yak breeders is lean meat production by hybridizing with other cattle, followed by wool production. The Indian government established a dedicated centre for research into yak husbandry, the ICAR-National Research Centre on Yak, in 1989. It

3483-650: The allele will have varying amounts of white hair scattered through its coat, particularly on the back and sides. About 25% of guinea pigs born to two roans are completely white , having two copies of the "roan" allele, and may have a constellation of deformities associated with "lethal white syndrome", although this condition has no relation to overo lethal white syndrome in horses or double merle syndrome in dogs. Lethal white guinea pigs ("lethals") often die shortly after birth or at weaning age, but with hand-feeding and regular dental care, lethals may live 2 to 3 years. Some lethals have reportedly lived to 6 or 7 years. It

3564-458: The beginning of the Holocene 11,700 years ago, a warmer climate and increasing human populations led to small-scale animal and plant domestication and an increased supply of food. The appearance of the domestic dog in the archaeological record, at least 15,000 years ago, was followed by domestication of livestock and of crops such as wheat and barley , the invention of agriculture , and

3645-584: The body. Except for white markings under the control of other genes, the head, mane, tail, and lower legs are dark. Roan is a simple dominant trait symbolized by the Rn allele . The University of California, Davis School of Veterinary Medicine 's genetics services have developed a DNA test that uses genetic markers to indirectly determine the number of Rn or rn alleles a horse has. The mutation responsible for true roan has not yet been identified exactly, but been assigned to equine chromosome 21 (ECA21) in

3726-422: The breed, domestic yak males are 111–138 cm (44–54 in) high at the withers, while females are 105–117 cm (41–46 in) high at the withers. Both sexes have long, shaggy hair with a dense woolly undercoat over the chest, flanks, and thighs to insulate them from the cold. Especially in bulls, this may form a long "skirt" that can reach the ground. The tail is long and horselike rather than tufted like

3807-562: The case of the termites, the relationship is a fully obligate symbiosis on both sides. Domestication (not to be confused with the taming of an individual animal ), is from the Latin domesticus , 'belonging to the house'. The term remained loosely defined until the 21st century, when the American archaeologist Melinda A. Zeder defined it as a long-term relationship in which humans take over control and care of another organism to gain

3888-458: The domesticated form of the animal, with Bos mutus ("mute ox") being the preferred name for the wild species. Although some authors still consider the wild yak to be a subspecies , Bos grunniens mutus , the ICZN made an official ruling in 2003 permitting the use of the name Bos mutus for wild yaks , and this is now the more common usage. There are no recognised subspecies of yak except where

3969-509: The domestication of animals involved violence against animals and damage to the environment. This, in turn, he argues, corrupted human ethics and paved the way for "conquest, extermination, displacement, repression, coerced and enslaved servitude, gender subordination and sexual exploitation, and hunger." Domesticated ecosystems provide food, reduce predator and natural dangers, and promote commerce, but their creation has resulted in habitat alteration or loss, and multiple extinctions commencing in

4050-515: The domestication syndrome; it is predicted that domestic animals are less resistant to parasites than their wild relatives. Domesticated birds principally mean poultry , raised for meat and eggs: some Galliformes ( chicken , turkey , guineafowl ) and Anseriformes (waterfowl: ducks , geese , and swans ). Also widely domesticated are cagebirds such as songbirds and parrots ; these are kept both for pleasure and for use in research. The domestic pigeon has been used both for food and as

4131-417: The form of scattered white hairs around the junction of the stifle and flank, and peculiar rings of white hairs near the base of the tail. This trait is called a coon tail or skunk tail . Some forms of sabino , which is a pinto pattern, have roaning along the edges of other white spots or markings A roan horse may not fit into any of the traditional categories as there is much still to be learned about

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4212-447: The freshwater cnidarian Hydra for research into genetics and physiology. Few have a long history of domestication. Most are used for food or other products such as shellac and cochineal . The phyla involved are Cnidaria , Platyhelminthes (for biological pest control ), Annelida , Mollusca , Arthropoda (marine crustaceans as well as insects and spiders), and Echinodermata . While many marine mollusks are used for food, only

4293-548: The gene responsible for roan cattle (KITLG) was refuted as a possible cause of roan in dogs. Neither roan nor ticking, if they are independently caused, appear to be recessive. Breeds of cattle known for roans are the Belgian Blue and Shorthorn . Among the former, coat color may be solid black, solid white, or blue roan; the latter may be solid red, solid white, or red roan. Belgian Blues also typically exhibit spotting patterns, which are genetically separate from roan. As

4374-426: The genetics of roan. The existence of other types of roaning conditions not covered by those mentioned here is possible and likely. The genetics behind roan dogs are still unclear, and at present candidate genes have been ruled out. There remains a great deal of ambiguity in terminology regarding mottled dogs, which are called roan , ticked , mottled and belton depending on the context. The roan or ticked color

4455-810: The genome and the epigenome , enabling a rapid evolutionary response to artificial selection. Polyploidy increases the number of chromosomes, bringing new combinations of genes and alleles, which in turn enable further changes such as by chromosomal crossover . The microbiome , the collection of microorganisms inhabiting the surface and internal tissue of plants, is affected by domestication. This includes changes in microbial species composition and diversity. Plant lineage, including speciation , domestication, and breeding , have shaped plant endophytes ( phylosymbiosis ) in similar patterns as plant genes. Several species of fungi have been domesticated for use directly as food, or in fermentation to produce foods and drugs. The cultivated mushroom Agaricus bisporus

4536-532: The homogenizing effect of gene flow from wild boars into pigs, and created domestication islands in the genome. The same process may apply to other domesticated animals. The 2023 parasite-mediated domestication hypothesis suggests that endoparasites such as helminths and protozoa could have mediated the domestication of mammals. Domestication involves taming, which has an endocrine component; and parasites can modify endocrine activity and microRNAs . Genes for resistance to parasites might be linked to those for

4617-627: The horns sweep out from the sides of the head and then curve backwards; they typically range from 48 to 99 cm (19 to 39 in) in length. The horns of females (cows) are smaller, at 27 to 64 cm (11 to 25 in) in length, and have a more upright shape. Both sexes have a short neck with a pronounced hump over the shoulders, although this is larger and more visible in males. Males weigh 350 to 585 kg (772 to 1,290 lb), females weigh 225 to 255 kg (496 to 562 lb). Wild (feral) yaks can be substantially heavier, bulls reaching weights of up to 1,000 kg (2,200 lb). Depending on

4698-426: 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 . Certain animal species, and certain individuals within those species, make better candidates for domestication because of their behavioral characteristics: The beginnings of mammal domestication involved

4779-494: The journey. They will starve unless they can be brought to a place where there is grass." They also are used to draw ploughs . Yaks' milk is often processed to a cheese called chhurpi in Tibetan and Nepali languages, and byaslag in Mongolia. Butter made from yaks' milk is an ingredient of the butter tea that Tibetans consume in large quantities, and is also used in lamps and made into butter sculptures used in religious festivities. Small numbers of herds can be found in

4860-580: The leaf material to the fungi that they tend. Some of these fungi are not fully domesticated: the fungi farmed by Mycocepurus smithii constantly produce spores that are not useful to the ants, which eat fungal hyphae instead. The process of domestication by Atta ants, on the other hand, is complete; it took 30 million years. Some 330 fungus-growing termite species of the subfamily Macrotermitinae cultivate Termitomyces fungi to eat; domestication occurred exactly once, 25–40 mya . The fungi, described by Roger Heim in 1942, grow on 'combs' formed from

4941-430: The other members of its designated genus. Apparent close fossil relatives of the yak, such as Bos baikalensis , have been found in eastern Russia, suggesting a possible route by which yak-like ancestors of the modern American bison could have entered the Americas. The species was originally designated as Bos grunniens ("grunting ox") by Linnaeus in 1766. Still, this name is now generally considered to refer only to

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5022-580: The pair soon rejoin the herd. Females of both the wild and domestic forms typically give birth only once every other year, although more frequent births are possible if the food supply is good. Calves are weaned at one year and become independent shortly thereafter. Wild calves are initially brown in color and only later develop darker adult hair. Females generally give birth for the first time at three or four years of age, and reach their peak reproductive fitness at around six years. Yaks may live for more than twenty years in domestication or captivity, although it

5103-419: The persistence of foetal haemoglobin throughout life. Conversely, yaks have trouble thriving at lower altitudes, and are prone to suffering from heat exhaustion above about 15 °C (59 °F). Further adaptations to the cold include a thick layer of subcutaneous fat and an almost complete lack of functional sweat glands . Compared with domestic cattle, the rumen of yaks is unusually large, relative to

5184-409: The presence and shape of which are determined by other genes. This is in stark contrast to true roan horses and roan cattle, which are roan only in pigmented regions of their coat and may have white markings. Instead, dogs with roaning or ticking are born with clear, open white markings which begin to fill in with flecking in the subsequent weeks and continue to darken with age. Most breed standards use

5265-649: The proto-Gyalrongic split (3221 [2169–4319] BP ) from Tibeto-Gyalrongic. The oldest dated physical evidence of yak domestication is from 2,500 years BP. In parts of Tibet and Karakorum, yak racing is a form of entertainment at traditional festivals and an important part of their culture. More recently, sports involving domesticated yaks, such as yak skiing or yak polo , are being marketed as tourist attractions in South Asian countries, including in Gilgit-Baltistan , Pakistan. In Nepal, an annual festival

5346-514: The relationship between them intensified, and humans' role in their survival and reproduction gradually led to formalized animal husbandry . Although the directed pathway for draft and riding animals proceeded from capture to taming, the other two pathways are not as goal-oriented, and archaeological records suggest that they took place over much longer time frames. Unlike other domestic species selected primarily for production-related traits, dogs were initially selected for their behaviors. The dog

5427-411: The rut, often while scent-marking with urine or dung. Females enter oestrus up to four times a year, and females are receptive only for a few hours in each cycle. Gestation lasts between 257 and 270 days, so that the young are born between May and June, and results in the birth of a single calf. The cow finds a secluded spot to give birth, but the calf can walk within about ten minutes of birth, and

5508-415: The scientific name of the domestic yak variant, Bos grunniens (grunting bull). Nikolay Przhevalsky named the wild variant Bos mutus (silent bull), believing that it did not make a sound at all, but it does. Yak physiology is well adapted to high altitudes , having larger lungs and heart than cattle found at lower altitudes, as well as greater capacity for transporting oxygen through their blood, due to

5589-459: The small number of traits that made domestic species different from their wild ancestors. He was also the first to recognize the difference between conscious selective breeding in which humans directly select for desirable traits and unconscious selection, in which traits evolve as a by-product of natural selection or from selection on other traits. There is a difference between domestic and wild populations; some of these differences constitute

5670-579: The summer, typically between July and September, depending on the local environment. For the remainder of the year, many bulls wander in small bachelor groups away from the large herds. Still, as the rut approaches, they become aggressive and regularly fight with each other to establish dominance. In addition to non-violent threat displays, bellowing, and scraping the ground with their horns, bull yaks compete more directly, repeatedly charging at each other with heads lowered or sparring with their horns. Like bison , but unlike cattle, males wallow in dry soil during

5751-451: The supposed primitive state of harmony with nature in hunter-gatherer societies, and replacing it, possibly violently or by enslavement, with a social hierarchy as property and power emerged. The dialectal naturalist Murray Bookchin has argued that domestication of animals, in turn, meant the domestication of humanity, both parties being unavoidably altered by their relationship with each other. The sociologist David Nibert asserts that

5832-429: The tails of cattle or bison. Domesticated yaks have a wide range of coat colours, with some individuals being white, grey, brown, roan or piebald . The udder in females and the scrotum in males are small and hairy as protection against the cold. Females have four teats . Yaks are not known to produce the characteristic lowing (mooing) sound of cattle, but both wild and domestic yaks grunt and squeak, which inspired

5913-614: The termites' excreta, dominated by tough woody fragments. The termites and the fungi are both obligate symbionts in the relationship. Roan (color) A horse with intermixed white and colored hairs of any color is usually called a roan. However, such mixtures, which can appear superficially similar, are caused by a number of separate genetic factors. Identifiable types of roans include true or classic roan , varnish roan , and rabicano , though other currently unknown factors may be responsible for ambiguous "roaning." Gray horses, which become lighter as they age until their hair coat

5994-421: The terms "ticked" and "roan" interchangeably, with the former referring to clearly defined flecks on a white background and the latter to flecks so closely spaced that the mixture appears even. The terminology that relates the underlying coat color with the roan modifier is often breed-specific, but most standards call a black dog with roaning blue . In breeds that are characterized by roaning and ticking such as

6075-637: The transition of humans from foraging to farming in different places and times across the planet. For instance, small-scale trial cultivation of cereals began some 28,000 years ago at the Ohalo II site in Israel. In the Fertile Crescent 11,000–10,000 years ago, zooarchaeology indicates that goats, pigs, sheep, and taurine cattle were the first livestock to be domesticated. Two thousand years later, humped zebu cattle were domesticated in what

6156-472: The wild yak is considered a subspecies of Bos grunniens . Yaks are heavily built animals with bulky frames, sturdy legs, rounded, cloven hooves, and extremely dense, long fur hanging lower than the belly. While wild yaks are generally dark, blackish to brown in colouration, domestic yaks can be quite variable, often having rusty brown and cream patches. They have small ears and broad foreheads, with smooth horns that are generally dark in colour. In males (bulls),

6237-408: The wild. 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 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

6318-462: The word, yak is usually used for both sexes, with bull or cow referring to each sex separately. Belonging to the genus Bos , Yaks are related to cattle ( Bos primigenius ). Mitochondrial DNA analyses to determine the evolutionary history of yaks have been inconclusive. The yak may have diverged from cattle at any point between one and five million years ago, and there is some suggestion that it may be more closely related to bison than to

6399-500: Was domesticated long before other animals, becoming established across Eurasia before the end of the Late Pleistocene era, well before agriculture . The archaeological and genetic data suggest that long-term bidirectional gene flow between wild and domestic stocks – such as in donkeys , horses , New and Old World camelids, goats, sheep, and pigs – was common. Human selection for domestic traits likely counteracted

6480-532: Was gradual and geographically diffuse – happening in many small steps and spread over a wide area – on the evidence of both archaeology and genetics. It was a process of intermittent trial and error and often resulted in diverging traits and characteristics. Whereas domestication of animals impacted most on the genes that controlled behavior, that of plants impacted most on the genes that controlled morphology (seed size, plant architecture, dispersal mechanisms) and physiology (timing of germination or ripening), as in

6561-557: Was triggered by the climatic and environmental changes that occurred after the peak of the Last Glacial Maximum and which continue to this present day. These changes made obtaining food by hunting and gathering difficult. The first animal to be domesticated was the dog at least 15,000 years ago. The Younger Dryas 12,900 years ago was a period of intense cold and aridity that put pressure on humans to intensify their foraging strategies but did not favour agriculture. By

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