The history of horse domestication has been subject to much debate, with various competing hypotheses over time about how domestication of the horse occurred. The main point of contention was whether the domestication of the horse occurred once in a single domestication event, or that the horse was domesticated independently multiple times. The debate was resolved at the beginning of the 21st century using DNA evidence that favored a mixed model in which domestication of the stallion most likely occurred only once, while wild mares of various regions were included in local domesticated herds. [1] [2]
In the 20th century, various ideas were postulated. One set hypothesized multiple ancestral body types of the single species Equus ferus or the original wild horse, each adapted to a given environment. [3] Another hypothesis held that prototypes originated from a single wild species and that all different body types were entirely a result of selective breeding after domestication. [4] Yet another proposed that the theoretical prototypes were each separate species or subspecies. [3] [4] These theories were all based on body types and conformation, prior to the availability of DNA for research, and have since been superseded by modern studies. [5] [2]
In the past, several theories were proposed about the origin of the domesticated horse and how the variety in horse breeds developed. They generally can be subdivided in two categories, single origin versus multiple origins.
The single origin theory holds that domestication occurred once, after which all breeds arose through selective breeding.
A theory associated with James Cossar Ewart in Scotland and Johann Ulrich Duerst in Germany postulated three primitive horse types, considered subspecies of Equus caballus, as ancestors of modern breeds. They were: [6]
To these Elwyn Hartley Edwards adds a fourth, the "Tundra Horse", supposedly ancestor of the Yakut pony, and "largely unconsidered by hippologists". [6]
A later theory associated with European scholars such as Jimmy Speed, Ruy d'Andrade, Hermann Ebhardt and Edward Skorkowski, postulated four basic body types, which were not considered to be named species. [6] They were:
American paleontologist Deb Bennett [7] [8] postulated that the early form of E. caballus developed into seven subspecies, [9] of which four supposedly contributed most to the ancestry of the domesticated horse, both directly and via assorted crossbred lineages between them. [10] These were:
The other three proposed subspecies were:
Modern genetic evidence now points at a single domestication event for a limited number of stallions, combined with repeated restocking of wild mares into domesticated herds. [12] This suggests that different body types might be a combination of both selective breeding and semi-feral landrace traits.
A study in 2012 that performed genomic sampling on 300 work horses from local areas as well as a review of previous studies of archaeology, mitochondrial DNA, and Y-DNA suggested that horses were originally domesticated in the western part of the Eurasian steppe. [13] Both domesticated stallions and mares spread out from this area, and then some additional wild mares were added from local herds; wild mares were easier to handle than wild stallions. Most other parts of the world were ruled out as sites for horse domestication, either due to climate unsuitable for an indigenous wild horse population or no evidence of domestication. It remains possible that a second, independent, domestication site might exist in the Iberian Peninsula, but the study could neither confirm nor disprove that hypothesis. [14]
The Przewalski's horse (now Equus ferus przewalskii) is currently believed to be unrelated to the modern domestic horse, though studies using DNA have had varied results. Recent mitochondrial DNA analysis suggests that the Przewalski and the modern domestic horse diverged some 160,000 years ago. [15] Studies using DNA have been inconclusive. A 2009 molecular study using ancient DNA (that is DNA recovered from archaeological finds like bones and teeth) places the Przewalski's horse in the middle of the domesticated horses. [16] These difficulties exist in part due to crossing domestic horses into the Przewalski's horse as well as the limited genetic variation present in the founder population of the modern Przewalski's Horse.
Chariot burials about 2500 BCE present the most direct hard evidence of horses used as working animals. Indirect evidence suggests that horses were ridden long before they were driven, approximately 3500 BCE. [17] One theory proposed was that the modern horse is descended from the Botai culture (in present-day Kazakhstan) where horses were milked and possibly ridden more than 5,000 years ago. A study of ancient and modern horse DNA concluded that modern horses do share a small amount of DNA with Botai horses but modern horses are not descendants of Botai horses. Przewalski's horse and Botai horses were both descendants of another domesticated horse they called the Borly4. [18]
However, modern domesticated breeds do not descend from the earliest domestic horse lineage at Botai. In 2021, it was reported that, according to a comprehensive genetic analysis, today's domestic horses descend from the lower Volga-Don region, Russia. 273 ancient horse genomes indicate that these populations replaced almost all local populations as they expanded rapidly throughout Eurasia from about 4200 years ago. It also shows that certain adaptations were strongly selected for by horse riding, and that equestrian material culture – including Sintashta spoke-wheeled chariots (but not Indo-European languages) spread alongside. In the case of Asia Indo-Iranian languages, chariots and horses spread together, "following the early second millennium BC Sintashta culture". [19] [20]
Equidae is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. The family evolved around 50 million years ago from a small, multi-toed ungulate into larger, single-toed animals. All extant species are in the genus Equus, which originated in North America. Equidae belongs to the order Perissodactyla, which includes the extant tapirs and rhinoceros, and several extinct families.
The horse is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of Equus ferus. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, close to Eohippus, into the large, single-toed animal of today. Humans began domesticating horses around 4000 BCE, and their domestication is believed to have been widespread by 3000 BCE. 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, which are horses that never have been domesticated and historically linked to the megafauna category of species. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, size, colors, markings, breeds, locomotion, and behavior.
A horse breed is a selectively bred population of domesticated horses, often with pedigrees recorded in a breed registry. However, the term is sometimes used in a broader sense to define landrace animals of a common phenotype located within a limited geographic region, or even feral "breeds" that are naturally selected. Depending on definition, hundreds of "breeds" exist today, developed for many different uses. Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance; "cold bloods," such as draft horses and some ponies, suitable for slow, heavy work; and "warmbloods," developed from crosses between hot bloods and cold bloods, often focusing on creating breeds for specific riding purposes, particularly in Europe.
How and when horses became domesticated has been disputed. Although horses appeared in Paleolithic cave art as early as 30,000 BC, these were wild horses and were probably hunted for meat. The clearest evidence of early use of the horse as a means of transport is from chariot burials dated c. 2000 BC. However, an increasing amount of evidence began to support the hypothesis that horses were domesticated in the Eurasian Steppes in approximately 3500 BC. Discoveries in the context of the Botai culture had suggested that Botai settlements in the Akmola Province of Kazakhstan are the location of the earliest domestication of the horse. Warmouth et al. (2012) pointed to horses having been domesticated around 3000 BC in what is now Ukraine and Western Kazakhstan.
Przewalski's horse, also called the takhi, Mongolian wild horse or Dzungarian horse, is a rare and endangered horse originally native to the steppes of Central Asia. It is named after the Russian geographer and explorer Nikolay Przhevalsky. Once extinct in the wild, since the 1990s it has been reintroduced to its native habitat in Mongolia in the Khustain Nuruu National Park, Takhin Tal Nature Reserve, and Khomiin Tal, as well as several other locales in Central Asia and Eastern Europe.
The Konik or Polish Konik, Polish: konik polski, is a Polish breed of small horse or pony. There are semi-feral populations in some regions. They are usually mouse dun or striped dun.
The tarpan was a free-ranging horse subspecies of the Eurasian steppe from the 18th to the 20th century. It is generally unknown whether those horses represented genuine wild horses, feral domestic horses or hybrids. The last individual believed to be a tarpan died in captivity in the Russian Empire in 1909.
Equus is a genus of mammals in the family Equidae, which includes horses, asses, and zebras. Within the Equidae, Equus is the only recognized extant genus, comprising seven living species. Like Equidae more broadly, Equus has numerous extinct species known only from fossils. The genus originated in North America and dispersed into the Old World and South America during the Early and Middle Pleistocene. Equines are odd-toed ungulates with slender legs, long heads, relatively long necks, manes, and long tails. All species are herbivorous, and mostly grazers, with simpler digestive systems than ruminants but able to subsist on lower-quality vegetation.
The wild horse is a species of the genus Equus, which includes as subspecies the modern domesticated horse as well as the endangered Przewalski's horse. The European wild horse, also known as the tarpan, that went extinct in the late 19th or early 20th century has previously been treated as the nominate subspecies of wild horse, Equus ferus ferus, but more recent studies have cast doubt on whether tarpans were truly wild or if they actually were feral horses or hybrids.
Equus lambei, commonly known as the Yukon horse or Yukon wild horse, is an extinct species of the genus Equus. Equus lambei ranged across North America until approximately 10,000 years ago. Based on recent examinations of the mtDNA of Equus lambei remains, scientists have concluded that E. lambei was probably much like the extinct tarpan, also known as the Eurasian wild horse, and the living Przewalski's horse. A partial carcass of Equus lambei is on display at the Yukon Beringia Interpretive Centre in Whitehorse, Yukon.
Wild horse is a species of the genus Equus that includes domesticated and undomesticated subspecies.
The Mongolian horse is the native horse breed of Mongolia. The breed is purported to be largely unchanged since the time of Genghis Khan. Nomads living in the traditional Mongol fashion still hold more than 3 million animals, which outnumber the country's human population. In Mongolia, the horses live outdoors all year, dealing with temperatures from 30 °C (86 °F) in summer down to −40 °C (−40 °F) in winter, and they graze and search for food on their own. The mare's milk is processed into the national beverage airag. Some animals are slaughtered for meat. Other than that, they serve as riding and transport animals; they are used both for the daily work of the nomads and in horse racing.
The horse has been present in the Indian subcontinent from at least the middle of the second millennium BC, more than two millennia after its domestication in Central Asia. The earliest uncontroversial evidence of horse remains on the Indian Subcontinent date to the early Swat culture. While horse remains and related artifacts have been found in Late Harappan sites, indicating that horses may have been present at Late Harappan times, horses did not play an essential role in the Harappan civilisation, in contrast to the Vedic period. The importance of the horse for the Indo-Aryans is indicated by the Sanskrit word Ashva, "horse," which is often mentioned in the Vedas and Hindu scriptures.
The evolution of the horse, a mammal of the family Equidae, occurred over a geologic time scale of 50 million years, transforming the small, dog-sized, forest-dwelling Eohippus into the modern horse. Paleozoologists have been able to piece together a more complete outline of the evolutionary lineage of the modern horse than of any other animal. Much of this evolution took place in North America, where horses originated but became extinct about 10,000 years ago, before being reintroduced in the 15th century.
The Botai culture is an archaeological culture (c. 3700–3100 BC) of prehistoric northern Central Asia. It was named after the settlement of Botai in today's northern Kazakhstan. The Botai culture has two other large sites: Krasnyi Yar, and Vasilkovka.
The term oriental horse refers to the ancient breeds of horses developed in the Middle East, such as the Arabian, Akhal-Teke, Barb, and the Turkoman horse. They tend to be thin-skinned, long-legged, slim in build and more physically refined than other types, but with great endurance. Oriental horses, sometimes referred to as hot-blooded breeds, have a level of intelligence that allows them to be athletic, versatile, and learn quickly. They are bred for agility and speed and are generally considered spirited and bold.
The Heck horse is a horse breed that is claimed to resemble the tarpan, an extinct wild equine. The breed was created by the German zoologist brothers Heinz Heck and Lutz Heck in an attempt to breed back the tarpan. Although unsuccessful at creating a genetic copy of the extinct species, they developed a breed with grullo coloration and primitive markings. Heck horses were subsequently exported to the United States, where a breed association was created in the 1960s.
A pony is a type of small horse. Depending on the context, a pony may be a horse that is under a given height at the withers, or a small horse with a specific conformation and temperament. Compared to a larger horse, a pony may have a thicker coat, mane and tail, with proportionally shorter legs, a wider barrel, heavier bone, a thicker neck and a shorter, broader head. The word pony derives from the old French poulenet, meaning foal, a young, immature horse.
Gallic horse, also known as Equus caballus gallicus, is a prehistoric subspecies of Equus caballus that lived in the Upper Paleolithic. It first appeared in the Aurignacian period because of climatic changes and roamed the territory of present-day France during the Gravettian and up to the end of the Solutrean. Its fossils, dated from 40,000 to around 15,000 years BC, are close to those of Equus caballus germanicus and may not correspond to a valid subspecies. First described by François Prat in 1968, it is around 1.40 m (4.6 ft) tall and differs from Equus caballus germanicus mainly in its dentition and slightly smaller size.
The expression "Solutré horse" refers to the remains of prehistoric equids discovered near the rock of Solutré by Adrien Arcelin and Henry Testot-Ferry in 1866, then studied by Professor Toussaint in 1874. This discovery gave rise to a popular legend about hunting in the abyss, according to which Paleolithic hunters guided herds of wild horses up the rock to precipitate them into the void and kill them. In reality, these migrating horses were slaughtered by men at the foot of the rock.