The horse is one of two extant subspecies of Equus ferus. It is an odd-toed ungulate mammal belonging to the taxonomic family Equidae; the horse has evolved over the past 45 to 55 million years from a small multi-toed creature, into the large, single-toed animal of today. Humans began domesticating horses around 4000 BC, their domestication is believed to have been widespread by 3000 BC. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses; these feral populations are not true wild horses, as this term is used to describe horses that have never been domesticated, such as the endangered Przewalski's horse, a separate subspecies, the only remaining true wild horse. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, colors, breeds and behavior. Horses' anatomy enables them to make use of speed to escape predators and they have a well-developed sense of balance and a strong fight-or-flight response.
Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down, with younger horses tending to sleep more than adults. Female horses, called mares, carry their young for 11 months, a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training in harness between the ages of two and four, they reach full adult development by age five, have an average lifespan of between 25 and 30 years. Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance. There are more than 300 breeds of horse in the world today, developed for many different uses. Horses and humans interact in a wide variety of sport competitions and non-competitive recreational pursuits, as well as in working activities such as police work, agriculture and therapy. Horses were used in warfare, from which a wide variety of riding and driving techniques developed, using many different styles of equipment and methods of control.
Many products are derived from horses, including meat, hide, hair and pharmaceuticals extracted from the urine of pregnant mares. Humans provide domesticated horses with food and shelter, as well as attention from specialists such as veterinarians and farriers. Specific terms and specialized language are used to describe equine anatomy, different life stages and breeds. Depending on breed and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and beyond; the oldest verifiable record was "Old Billy", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, listed in Guinness World Records as the world's oldest living pony, died in 2007 at age 56. Regardless of a horse or pony's actual birth date, for most competition purposes a year is added to its age each January 1 of each year in the Northern Hemisphere and each August 1 in the Southern Hemisphere; the exception is in endurance riding, where the minimum age to compete is based on the animal's actual calendar age.
The following terminology is used to describe horses of various ages: Foal: A foal of either sex less than one year old. A nursing foal is sometimes called a suckling and a foal, weaned is called a weanling. Most domesticated foals are weaned at five to seven months of age, although foals can be weaned at four months with no adverse physical effects. Yearling: A horse of either sex, between one and two years old. Colt: A male horse under the age of four. A common terminology error is to call any young horse a "colt", when the term only refers to young male horses. Filly: A female horse under the age of four. Mare: A female horse four years old and older. Stallion: A non-castrated male horse four years old and older; the term "horse" is sometimes used colloquially to refer to a stallion. Gelding: A castrated male horse of any age. In horse racing, these definitions may differ: For example, in the British Isles, Thoroughbred horse racing defines colts and fillies as less than five years old. However, Australian Thoroughbred racing defines fillies as less than four years old.
The height of horses is measured at the highest point of the withers. This point is used because it is a stable point of the anatomy, unlike the head or neck, which move up and down in relation to the body of the horse. In English-speaking countries, the height of horses is stated in units of hands and inches: one hand is equal to 4 inches; the height is expressed as the number of full hands, followed by a point the number of additional inches, ending with the abbreviation "h" or "hh". Thus, a horse described; the size of horses varies by breed, but is influenced by nutrition. Light riding horses range in height from 14 to 16 hands and can weigh from 380 to 550 kilograms. Larger riding horses start at about 15.2 hands and are as tall as 17 hands, weighing from 500 to 600 kilograms. Heavy or draft horses are at least 16 hands (64 inches, 16
Equine conformation evaluates the degree of correctness of a horse's bone structure and its body proportions in relation to each other. Undesirable conformation can limit the ability to perform a specific task. Although there are several universal "faults," a horse's conformation is judged by what its intended use may be, thus "form to function" is one of the first set of traits considered in judging conformation. A horse with poor form for a Grand Prix show jumper could have excellent conformation for a World Champion cutting horse, or to be a champion draft horse; every horse has good and bad points of its conformation and many horses excel with conformation faults. The standard of the ideal head varies from breed to breed based on a mixture of the role the horse is bred for and what breeders and enthusiasts find appealing. Breed standards cite large eyes, a broad forehead and a dry head-to-neck connection as important to correctness about the head. Traditionally, the length of head as measured from poll to upper lip should be two-thirds the length of the neck topline.
The construction of the horse's head influences its breathing, though there are few studies to support this. A width of 4 fingers or 7.2 cm was associated with an unrestricted airflow and greater endurance. However, a study in 2000 which compared the intermandibular width-to-size ratio of Thoroughbreds with their racing success showed this to be untrue; the relationship between head conformation and performance are not well understood, an appealing head may be more a matter of marketability than performance. Among mammals, morphology of the head plays a role in temperature regulation. Many ungulates have a specialized network of blood vessels called the carotid rete, which keeps the brain cool while the body temperature rises during exercise. Horses lack a carotid rete and instead use their sinuses to cool blood around the brain; these factors suggest that the conformation of a horse's head influences its ability to regulate temperature. A horse with a dished face or dished head has a muzzle with a concave profile on top further emphasized by slight bulging of forehead.
Dished heads are associated with Arabians and Arabian-influenced breeds, which excel at Endurance riding and were bred in the arid Arabian desert. There are several theories regarding the adaptive role of the dished head, it may be an adaptation to increase aerobic endurance. Dished head is not considered a deformity. A Roman nose is a muzzle with a convex profile. Convex heads are associated with Baroque horse breeds and horses from cold regions; this trait plays a role in warming air as it is inhaled, but may influence aerobic capacity. Roman nose is not considered a deformity. A horse with small nostrils or small nares can be found in any breed and accompanies a narrow jaw and muzzle. Small nostrils limit the horse's ability to breathe hard while exerting itself; this affects horses in high-speed activities or those that need to sustain effort over long duration. Horses with small nostrils are therefore best used for non-speed sports. A horse with pig eye has unusually small eyes; this is an aesthetic issue, but claimed by some to be linked to stubbornness or nervousness, thought to decrease the horse's visual field.
The lower jaw should be defined. The space between the two sides of the jawbone should be wide, with room for the larynx and muscle attachments; the width should be 7.2 cm, about the width of a fist. The jaw is called narrow; the jaw is called large. A large jaw adds weight to the head. Too large of a jaw can cause a reduction to the horse's ability to flex at the poll to bring his head and neck into proper position for collection and to help balance. A parrot mouth is an overbite; this can affect the horse's ability to graze. Parrot mouth can be managed with regular teeth floating by a veterinarian. A monkey mouth, sow mouth, or bulldog mouth is an underbite, where the lower jaw extends further out than the upper jaw; this is less common than parrot mouth. This can affect the horse's ability to graze. Monkey mouth can be managed with regular teeth floating by a veterinarian. Ears should be proportional to the head, they should be set just below the level of the poll at the top of the head. Ears should be a position and backward.
Ears that are too large or too small may make the head seem too small or large in proportion with the body. A neck of ideal length is about one third of the horse's length, measured from poll to withers, with a length comparable to the length of the legs. An ideally placed neck is called a horizontal neck, it is set on the chest neither too high nor too low, with its weight and balance aligned with the forward movement of the body. The horse is easy to supple, develop strength, to control with hand and legs aids. Although uncommon, it is seen in Thoroughbreds, American Quarter Horses, some Warmbloods. Horizontal neck is advantageous to every sport, as the neck is flexible and works well for balancing. A short neck is one, less than one third the length of the horse. Short necks are common, found in any breed. A short neck hinders the balancing ability of the horse, making it more prone to stumbling and clumsiness. A short neck adds more weight on the foreha
Quadrupedalism or pronograde posture is a form of terrestrial locomotion in animals using four limbs or legs. An animal or machine that moves in a quadrupedal manner is known as a quadruped, meaning "four feet"; the majority of quadrupeds are vertebrate animals, including mammals such as cattle and cats, reptiles such as lizards. Few other animals are quadrupedal, though a few birds like the shoebill sometimes use their wings to right themselves after lunging at prey. Although the words quadruped and tetrapod are both derived from terms meaning "four-footed", they have distinct meanings. A tetrapod is any member of the taxonomic unit Tetrapoda whereas a quadruped uses four limbs for locomotion. Not all tetrapods are quadrupeds and not all quadrupeds are tetrapods; the distinction between quadrupeds and tetrapods is important in evolutionary biology in the context of tetrapods whose limbs have adapted to other roles. All of these animals are tetrapods. Snakes, whose limbs have become vestigial or lost are tetrapods.
Most quadrupedal animals are tetrapods but there are a few exceptions. For instance, among the insects, the praying mantis is a quadruped. In July 2005, in rural Turkey, scientists discovered five Kurdish siblings who had learned to walk on their hands and feet. Unlike chimpanzees, which ambulate on their knuckles, the Kurdish siblings walked on their palms, allowing them to preserve the dexterity of their fingers. Many people practitioners of parkour and freerunning and Georges Hébert's Natural Method, find benefit in quadrupedal movements to build full body strength. Kenichi Ito is a Japanese man famous for speed running on four limbs. Quadrupedalism is sometimes referred to as being on all fours, is observed in crawling by infants. BigDog is a dynamically stable quadruped robot created in 2005 by Boston Dynamics with Foster-Miller, the NASA Jet Propulsion Laboratory, the Harvard University Concord Field Station. By NASA JPL, in collaboration with University of California, Santa Barbara Robotics Lab, is RoboSimian, with emphasis on stability and deliberation.
It has been demonstrated at the DARPA Robotics Challenge. Bipedalism Orthograde posture Family may provide evolution clue - BBC News
The domestic dog is a member of the genus Canis, which forms part of the wolf-like canids, is the most abundant terrestrial carnivore. The dog and the extant gray wolf are sister taxa as modern wolves are not related to the wolves that were first domesticated, which implies that the direct ancestor of the dog is extinct; the dog was the first species to be domesticated and has been selectively bred over millennia for various behaviors, sensory capabilities, physical attributes. Their long association with humans has led dogs to be uniquely attuned to human behavior and they are able to thrive on a starch-rich diet that would be inadequate for other canid species. Dogs vary in shape and colors, they perform many roles for humans, such as hunting, pulling loads, assisting police and military, companionship and, more aiding disabled people and therapeutic roles. This influence on human society has given them the sobriquet of "man's best friend"; the term dog is applied both to the species as a whole, any adult male member of the same.
An adult female is a bitch. An adult male capable of reproduction is a stud. An adult female capable of reproduction is brood mother. Immature males or females are puppies. A group of pups from the same gestation period is called a litter; the father of a litter is a sire. It is possible for one litter to have multiple sires; the mother of a litter is a dam. A group of any three or more adults is a pack. In 1999, a study of mitochondrial DNA indicated that the domestic dog may have originated from multiple grey wolf populations, with the dingo and New Guinea singing dog "breeds" having developed at a time when human populations were more isolated from each other. In the third edition of Mammal Species of the World published in 2005, the mammalogist W. Christopher Wozencraft listed under the wolf Canis lupus its wild subspecies, proposed two additional subspecies: "familiaris Linneaus, 1758 " and "dingo Meyer, 1793 ". Wozencraft included hallstromi – the New Guinea singing dog – as a taxonomic synonym for the dingo.
Wozencraft referred to the mDNA study as one of the guides in forming his decision. The inclusion of familiaris and dingo under a "domestic dog" clade has been noted by other mammalogists; this classification by Wozencraft is debated among zoologists. The origin of the domestic dog includes the dog's evolutionary divergence from the wolf, its domestication, its development into dog types and dog breeds; the dog is a member of the genus Canis, which forms part of the wolf-like canids, was the first species and the only large carnivore to have been domesticated. The dog and the extant gray wolf are sister taxa, as modern wolves are not related to the population of wolves, first domesticated; the genetic divergence between dogs and wolves occurred between 40,000–20,000 years ago, just before or during the Last Glacial Maximum. This timespan represents the upper time-limit for the commencement of domestication because it is the time of divergence and not the time of domestication, which occurred later.
The domestication of animals commenced over 15,000 years ago, beginning with the grey wolf by nomadic hunter-gatherers. The archaeological record and genetic analysis show the remains of the Bonn–Oberkassel dog buried beside humans 14,200 years ago to be the first undisputed dog, with disputed remains occurring 36,000 years ago, it was not until 11,000 years ago that people living in the Near East entered into relationships with wild populations of aurochs, boar and goats. Where the domestication of the dog took place remains debated, with the most plausible proposals spanning Western Europe, Central Asia and East Asia; this has been made more complicated by the recent proposal that an initial wolf population split into East and West Eurasian groups. These two groups, before going extinct, were domesticated independently into two distinct dog populations between 14,000 and 6,400 years ago; the Western Eurasian dog population was and replaced by East Asian dogs introduced by humans at least 6,400 years ago.
This proposal is debated. Domestic dogs have been selectively bred for millennia for various behaviors, sensory capabilities, physical attributes. Modern dog breeds show more variation in size and behavior than any other domestic animal. Dogs are predators and scavengers, like many other predatory mammals, the dog has powerful muscles, fused wrist bones, a cardiovascular system that supports both sprinting and endurance, teeth for catching and tearing. Dogs are variable in height and weight; the smallest known adult dog was a Yorkshire Terrier, that stood only 6.3 cm at the shoulder, 9.5 cm in length along the head-and-body, weighed only 113 grams. The largest known dog was an English Mastiff which weighed 155.6 kg and was 250 cm from the snout to the tail. The tallest dog is a Great Dane; the dog's senses include vision, sense of smell, sense of taste and sensitivity to the earth's magnetic field. Another study suggested; the coats of domestic dogs are of two varieties: "double" being common with dogs originating from colder climates, made up of a coarse guard hair and a soft down hair, or "single", with the topcoat only.
Breeds may have stripe, or "star" of white fur on their chest or underside. Regarding coat appearance or h
The Thoroughbred is a horse breed best known for its use in horse racing. Although the word thoroughbred is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed. Thoroughbreds are considered "hot-blooded" horses that are known for their agility and spirit; the Thoroughbred as it is known today was developed in 17th- and 18th-century England, when native mares were crossbred with imported Oriental stallions of Arabian and Turkoman breeding. All modern Thoroughbreds can trace their pedigrees to three stallions imported into England in the 17th century and 18th century and to a larger number of foundation mares of English breeding. During the 18th and 19th centuries, the Thoroughbred breed spread throughout the world. Millions of Thoroughbreds exist today, around 100,000 foals are registered each year worldwide. Thoroughbreds are used for racing, but are bred for other riding disciplines such as show jumping, combined training, dressage and fox hunting.
They are commonly crossbred to create new breeds or to improve existing ones, have been influential in the creation of the Quarter Horse, Anglo-Arabian, various warmblood breeds. Thoroughbred racehorses perform with maximum exertion, which has resulted in high accident rates and health problems such as bleeding from the lungs. Other health concerns include low fertility, abnormally small hearts and a small hoof-to-body-mass ratio. There are several theories for the reasons behind the prevalence of accidents and health problems in the Thoroughbred breed, research is ongoing; the typical Thoroughbred ranges from 15.2 to 17.0 hands high. They are most bay, dark bay or brown, black, or gray. Less common colors recognized in the United States include palomino. White is rare, but is a recognized color separate from gray; the face and lower legs may be marked with white, but white will not appear on the body. Coat patterns that have more than one color on the body, such as Pinto or Appaloosa, are not recognized by mainstream breed registries.
Good-quality Thoroughbreds have a well-chiseled head on a long neck, high withers, a deep chest, a short back, good depth of hindquarters, a lean body, long legs. Thoroughbreds are classified among the "hot-blooded" breeds, which are animals bred for agility and speed and are considered spirited and bold. Thoroughbreds born in the Northern Hemisphere are considered a year older on the first of January each year; these artificial dates have been set to enable the standardization of races and other competitions for horses in certain age groups. The Thoroughbred is a distinct breed of horse, although people sometimes refer to a purebred horse of any breed as a thoroughbred; the term for any horse or other animal derived from a single breed line is purebred. While the term came into general use because the English Thoroughbred's General Stud Book was one of the first breed registries created, in modern usage horse breeders consider it incorrect to refer to any animal as a thoroughbred except for horses belonging to the Thoroughbred breed.
Nonetheless, breeders of other species of purebred animals may use the two terms interchangeably, though thoroughbred is less used for describing purebred animals of other species. The term is a proper noun referring to this specific breed, though not capitalized in non-specialist publications, outside the US. For example, the Australian Stud Book, The New York Times, the BBC do not capitalize the word. Flat racing existed in England by at least 1174, when four-mile races took place at Smithfield, in London. Racing continued at fairs and markets throughout the Middle Ages and into the reign of King James I of England, it was that handicapping, a system of adding weight to attempt to equalize a horse's chances of winning as well as improved training procedures, began to be used. During the reigns of Charles II, William III, George I, the foundation of the Thoroughbred was laid; the term "thro-bred" to describe horses was first used in 1713. Under Charles II, a keen racegoer and owner, Anne, royal support was given to racing and the breeding of race horses.
With royal support, horse racing became popular with the public, by 1727, a newspaper devoted to racing, the Racing Calendar, was founded. Devoted to the sport, it recorded race results and advertised upcoming meets. All modern Thoroughbreds trace back to three stallions imported into England from the Middle East in the late 17th and early 18th centuries: the Byerley Turk, the Darley Arabian, the Godolphin Arabian. Other stallions of oriental breeding were less influential, but still made noteworthy contributions to the breed; these included the Alcock's Arabian, D'Arcy's White Turk, Leedes Arabian, Curwen's Bay Barb. Another was the Brownlow Turk, among other attributes, is thought to be responsible for the gray coat color in Thoroughbreds. In all, about 160 stallions of Oriental breeding have been traced in the historical record as contributing to the creation of the Thoroughbred; the addition of horses of Eastern bloodlines, whether Arabian, Barb, or Turk, to the native English mares led to the creation of the General Stud Book in 1791 and the practice of official registration of horses.
According to Peter Willett, about 50% of the foundation stallions appear to have been of Arabian bloodlines, wit
Zebras are several species of African equids united by their distinctive black-and-white striped coats. Their stripes come in different patterns, unique to each individual, they are social animals that live in small harems to large herds. Unlike their closest relatives and donkeys, zebras have never been domesticated. There are three species of zebras: the mountain zebra and the Grévy's zebra; the plains zebra and the mountain zebra belong to the subgenus Hippotigris, while Grévy's zebra is the sole species of subgenus Dolichohippus. The latter resembles an ass, to which zebras are related, while the former two look more horse-like. All three belong to the genus Equus, along with other living equids; the unique stripes of zebras make them one of the animals most familiar to people. They occur in a variety of habitats, such as grasslands, woodlands, thorny scrublands and coastal hills. Various anthropogenic factors have had a severe impact on zebra populations, in particular hunting for skins and habitat destruction.
Grévy's zebra and the mountain zebra are endangered. While plains zebras are much more plentiful, one subspecies, the quagga, became extinct in the late 19th century – though there is a plan, called the Quagga Project, that aims to breed zebras that are phenotypically similar to the quagga in a process called breeding back; the name "zebra" in English dates back to c. 1600, from Italian zebra from Portuguese, which in turn is said to be Congolese. The Encarta Dictionary says its ultimate origin is uncertain, but it may come from Latin equiferus meaning "wild horse"; the word was traditionally pronounced with a long initial vowel, but over the course of the 20th century, the pronunciation with the short initial vowel became the usual one in the UK and Commonwealth. The pronunciation with a long initial vowel remains standard in the United States. A group of zebras are referred to dazzle, or zeal. Zebras evolved among the Old World horses within the last 4 million years, it has been suggested that striped equids evolved more than once.
Extensive stripes are posited to have been of little use to equids that live in low densities in deserts or ones that live in colder climates with shaggy coats and annual shading. However, molecular evidence supports zebras as a monophyletic lineage; the zebra has between 46 chromosomes, depending on the species. There are three extant species. Collectively, two of the species have eight subspecies. Zebra populations are diverse, the relationships between, the taxonomic status of, several of the subspecies are not well known. Genus: Equus Subgenus: Hippotigris Plains zebra, Equus quagga †Quagga, Equus quagga quagga Burchell's zebra, Equus quagga burchellii Grant's zebra, Equus quagga boehmi Selous' zebra, Equus quagga selousi Maneless zebra, Equus quagga borensis Chapman's zebra, Equus quagga chapmani Crawshay's zebra, Equus quagga crawshayi Mountain zebra, Equus zebra Cape mountain zebra, Equus zebra zebra Hartmann's mountain zebra, Equus zebra hartmannae Subgenus: Dolichohippus Grévy's zebra, Equus grevyi The plains zebra is the most common, has or had about six subspecies distributed across much of southern and eastern Africa.
It, or particular subspecies of it, have been known as the common zebra, the dauw, Burchell's zebra, Chapman's zebra, Wahlberg's zebra, Selous' zebra, Grant's zebra, Boehm's zebra and the quagga. The mountain zebra of southwest Africa tends to have a sleek coat with a white belly and narrower stripes than the plains zebra, it is classified as vulnerable. Grévy's zebra is the largest type, with a narrow head, making it appear rather mule-like, it is an inhabitant of the semi-arid grasslands of northern Kenya. Grévy's zebra is the rarest species, is classified as endangered. Although zebra species may have overlapping ranges, they do not interbreed. In captivity, plains zebras have been crossed with mountain zebras; the hybrid foals lacked a dewlap and resembled the plains zebra apart from their larger ears and their hindquarters pattern. Attempts to breed a Grévy's zebra stallion to mountain zebra mares resulted in a high rate of miscarriage. In captivity, crosses between zebras and other equines have produced several distinct hybrids, including the zebroid, zeedonk and zorse.
In certain regions of Kenya, plains zebras and Grévy's zebra coexist, fertile hybrids occur. The Hagerman horse is sometimes referred to as the American zebra due to perceived similarities to the plains zebra, sometimes depicted as striped. However, consensus appears to be that it wasn't closely related to either Hippotigiris nor Dolichohippus, nor is there unambiguous evidence that it had stripes; the common plains zebra is about 1.2–1.3 m at the shoulder with a body ranging from 2–2.6 m long with a 0.5 m tail. It can weigh up to 350 kg, males being bigger than females. Grévy's zebra is larger, while the mountain zebra is somewhat smaller, it was believed that zebras were white animals with black stripes, since some zebras have white underbellies. Embryological evidence, shows that the animal's background colour is black and the white stripes and bellies are additions, it is that the stripes ar
Dog breeds are dogs that have uniform physical characteristics developed by humans, with breeding animals selected for phenotypic traits such as size, coat color and behavior. The Fédération Cynologique Internationale recognizes 337 pure dog breeds. Other uses of the term breed when referring to dogs may include pure breeds, cross-breeds, mixed breeds and natural breeds; the domestic dog is the first species, the only large carnivore, to have been domesticated. Over the past 200 years, dogs have undergone rapid phenotypic change and were formed into today's modern breeds due to artificial selection imposed by humans; these breeds can vary in weight from a 0.46 kg teacup poodle to a 90 kg giant mastiff. The skull and limb proportions vary between breeds, with dogs displaying more phenotypic diversity than can be found within the entire order of carnivores; some breeds demonstrate outstanding skills in herding, scent detection, guarding, which demonstrates the functional and behavioral diversity of dogs.
The first dogs were wolflike, but the phenotypic changes that coincided with the dog–wolf genetic divergence are not known. In 2017, a study showed that 9,000 years ago the domestic dog was present at what is now Zhokhov Island, arctic north-eastern Siberia, connected to the mainland at that time; the dogs were selectively bred as either sled dogs or as hunting dogs, which implies that a sled dog standard and a hunting dog standard existed at that time. The optimal maximum size for a sled dog is 20–25 kg based on thermo-regulation, the ancient sled dogs were between 16–25 kg; the same standard has been found in the remains of sled dogs from this region 2,000 ago and in the modern Siberian Husky breed standard. Other dogs were more massive at 30 kg and appear to be dogs, crossed with wolves and used for polar-bear hunting. At death, the heads of the dogs had been separated from their bodies by humans for ceremonial reasons. Between 3,000 and 4,000 years ago greyhound-type dogs were depicted on pottery and paintings in Egypt and Western Asia.
Mastiff-type dogs were kept for guarding and hunting, short-legged dogs were bred. Most modern dog breeds are the products of the controlled breeding practices of the Victorian era, the accurate documenting of pedigrees with the establishment of the English Kennel Club in 1873 in imitation of other stud book registries for cattle and horses. For early depictions of dogs in art, see early history in art. Ancient breed of dogs was a term once used for a group of dog breeds by the American Kennel Club, but no longer; these breeds were referred to as "ancient breeds", as opposed to modern breeds because it was believed that they had origins dating back over 500 years. In 2004, a study looked at the microsatellites of 414 purebred dogs representing 85 breeds; the study found that dog breeds were so genetically distinct that 99% of individual dogs could be assigned to their breed based on their genotype, indicating that breeding barriers has led to distinct genetic units. The study identified 9 breeds that could be represented on the branches of a phylogenetic tree which grouped together with strong statistical support and could be separated from the other breeds with a modern European origin.
These 9 breeds had been referred to as opposed to the modern breeds. The study found that the Pharaoh Hound and Ibizan Hound were not as old as believed but had been recreated from combinations of other breeds, that the Norwegian Elkhound grouped with the other European dogs despite reports of direct Scandinavian origins dating back 5,000 years; the dog which accompanied the ancestors of Native Americans from Siberia is extinct. See further: Dog typeThe spread of modern dog breeds has been difficult to resolve because many are the products of the controlled breeding practices of the Victorian era. In 2010, a study looked at 48,000 single nucleotide polymorphisms that gave a genome-wide coverage of 912 dogs representing 85 breeds; the study found distinct genetic clusters within modern dogs that corresponded to phenotype or function. These included spitz-breeds, toy dogs, Mastiff-like breeds, small terriers, herding dogs, scent-hounds, sight-hounds. There were 17 breeds that conflicted with phenotype or function and these were thought to be the result of crossing some of the other phenotypes.
As in a 2004 study that found 9 ‘ancient breeds’ to be genetically divergent, the study found 13 breeds that were genetically divergent from the modern breeds: the Basenji, Afghan hound, Canaan dog, New Guinea singing dog, Chow Chow, Chinese Shar Pei, Alaskan malamute, Siberian husky and American Eskimo dog. Results indicated that the Basenji had recent admixture with Middle Eastern wolves; the study found that there were three well-supported groups that were divergent and distinct from modern domestic dogs. The three groups were an Asian group that showed past admixture with Chinese wolves, a Middle Eastern group, a northern group. In 2012, a study looked at 49,000 Single nucleotide polymorphisms that gave a genome-wide coverage of 1,375 dogs representing 35 breeds, 19 wolves, previous published genetic signatures of other breeds, giving a total of 121 breeds covered; the study found a deep genetic split between old-world and new-world wolves, confirmed the genetic divergence of 13 breeds from a 2010 study (Afghan Hound, Alaskan Malamute, American Eskimo, Canaan dog, Chow Chow, D