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98-437: A pony is a type of small horse ( Equus ferus caballus ). 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

196-533: A feral horse that lives on Assateague Island off the coasts of Maryland and Virginia , often matures to the height of an average small horse when raised from a foal under domesticated conditions. Conversely, the term "pony" is occasionally used to describe horses of normal height. Horses used for polo are often called " polo ponies " regardless of height, even though they are often of Thoroughbred breeding and often well over 14.2 hands (58 inches, 147 cm). American Indigenous tribes also have

294-662: A saddle or in a harness between the ages of two and four. They reach full adult development by age five, and 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; "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. There are more than 300 breeds of horse in

392-466: A " galloway ", and ponies in Australia measure under 14 hands (56 inches, 142 cm). Ponies originally developed as a landrace adapted to a harsh natural environment, and were considered part of the "draft" subtype typical of Northern Europe. At one time, it was hypothesized that they may have descended from a wild "draft" subspecies of Equus ferus. Studies of mitochondrial DNA (which

490-484: A bird feeds a brood parasite such as a cuckoo , it is unwittingly extending its phenotype; and when genes in an orchid affect orchid bee behavior to increase pollination, or when genes in a peacock affect the copulatory decisions of peahens, again, the phenotype is being extended. Genes are, in Dawkins's view, selected by their phenotypic effects. Other biologists broadly agree that the extended phenotype concept

588-454: A clear hierarchy of rank, led by a dominant individual, usually a mare. They are also social creatures that are able to form companionship attachments to their own species and to other animals, including humans. They communicate in various ways, including vocalizations such as nickering or whinnying, mutual grooming , and body language . Many horses will become difficult to manage if they are isolated, but with training, horses can learn to accept

686-428: A constant eye out for danger. Unlike humans, horses do not sleep in a solid, unbroken period of time, but take many short periods of rest. Horses spend four to fifteen hours a day in standing rest, and from a few minutes to several hours lying down. Total sleep time in a 24-hour period may range from several minutes to a couple of hours, mostly in short intervals of about 15 minutes each. The average sleep time of

784-559: A domestic horse is said to be 2.9 hours per day. Horses must lie down to reach REM sleep . They only have to lie down for an hour or two every few days to meet their minimum REM sleep requirements. However, if a horse is never allowed to lie down, after several days it will become sleep-deprived, and in rare cases may suddenly collapse because it slips, involuntarily, into REM sleep while still standing. This condition differs from narcolepsy , although horses may also suffer from that disorder. Phenotype Wilhelm Johannsen proposed

882-473: A full 60 calendar months (five years) old. The horse skeleton averages 205 bones. A significant difference between the horse skeleton and that of a human is the lack of a collarbone —the horse's forelimbs are attached to the spinal column by a powerful set of muscles, tendons, and ligaments that attach the shoulder blade to the torso. The horse's four legs and hooves are also unique structures. Their leg bones are proportioned differently from those of

980-435: A full-sized adult rider. Pound for pound ponies can pull and carry more weight than a horse. Draft-type ponies are able to pull loads significantly greater than their own weight, with larger ponies capable of pulling loads comparable to those pulled by full-sized draft horses , and even very small ponies are able to pull as much as 450 percent of their own weight. Nearly all pony breeds are very hardy, easy keepers that share

1078-518: A gene has on its surroundings, including other organisms, as an extended phenotype, arguing that "An animal's behavior tends to maximize the survival of the genes 'for' that behavior, whether or not those genes happen to be in the body of the particular animal performing it." For instance, an organism such as a beaver modifies its environment by building a beaver dam ; this can be considered an expression of its genes , just as its incisor teeth are—which it uses to modify its environment. Similarly, when

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1176-478: A good 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 significantly more than adults. Female horses, called mares , carry their young for approximately 11 months and a young horse, called a foal , can stand and run shortly following birth. Most domesticated horses begin training under

1274-640: A high level of intelligence that may or may not be used to cooperate with human handlers. Small size, by itself, is not an exclusive determinant. For example, the Shetland pony which averages 10 hands (40 inches, 102 cm), is considered a pony. Conversely, breeds such as the Falabella and other miniature horses , which can be no taller than 76 centimetres; 7.2 hands (30 in), are classified by their registries as very small horses, not ponies. Horses have 64 chromosomes . The horse genome

1372-439: A higher rate of gastric ulcers than horses listening to music, and racehorses stabled where a radio was played had a higher overall rate of ulceration than horses stabled where there was no radio playing. Horses have a great sense of balance, due partly to their ability to feel their footing and partly to highly developed proprioception —the unconscious sense of where the body and limbs are at all times. A horse's sense of touch

1470-502: A horse, their legs are proportionately shorter. They have strong hooves and grow a heavier hair coat , seen in a thicker mane and tail as well as a particularly heavy winter coat. Pony breeds have developed all over the world, particularly in cold and harsh climates where hardy, sturdy working animals were needed. They are remarkably strong for their size. Breeds such as the Connemara pony are recognized for their ability to carry

1568-413: A human as a companion, and thus be comfortable away from other horses. However, when confined with insufficient companionship, exercise, or stimulation, individuals may develop stable vices , an assortment of bad habits, mostly stereotypies of psychological origin, that include wood chewing, wall kicking, "weaving" (rocking back and forth), and other problems. Studies have indicated that horses perform

1666-420: A human. For example, the body part that is called a horse's "knee" is actually made up of the carpal bones that correspond to the human wrist . Similarly, the hock contains bones equivalent to those in the human ankle and heel . The lower leg bones of a horse correspond to the bones of the human hand or foot, and the fetlock (incorrectly called the "ankle") is actually the proximal sesamoid bones between

1764-529: A large part of the Human Genome Project . Phenomics has applications in agriculture. For instance, genomic variations such as drought and heat resistance can be identified through phenomics to create more durable GMOs. Phenomics may be a stepping stone towards personalized medicine , particularly drug therapy . Once the phenomic database has acquired enough data, a person's phenomic information can be used to select specific drugs tailored to

1862-526: A major component of grass, through the process of hindgut fermentation . Cellulose fermentation by symbiotic bacteria and other microbes occurs in the cecum and the large intestine . Horses cannot vomit , so digestion problems can quickly cause colic , a leading cause of death. Although horses do not have a gallbladder , they tolerate high amounts of fat in their diet. The horses' senses are based on their status as prey animals , where they must be aware of their surroundings at all times. The equine eye

1960-566: A margin for competition measurement of up to 150 centimetres (59.1 in; 14.3 hands) without shoes, or 151 centimetres (59.45 in; 14. 3 + 1 ⁄ 2 hands) with shoes. However, the term pony can be used in general (or affectionately) for any small horse, regardless of its actual size or breed. Furthermore, some horse breeds may have individuals who mature under that height but are still called horses and are allowed to compete as horses. In Australia, horses that measure from 14 to 15 hands (142 to 152 cm; 56 to 60 inches) are known as

2058-537: A multidimensional search space with several neurobiological levels, spanning the proteome, cellular systems (e.g., signaling pathways), neural systems and cognitive and behavioural phenotypes." Plant biologists have started to explore the phenome in the study of plant physiology. In 2009, a research team demonstrated the feasibility of identifying genotype–phenotype associations using electronic health records (EHRs) linked to DNA biobanks . They called this method phenome-wide association study (PheWAS). Inspired by

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2156-797: A number of cognitive tasks on a daily basis, meeting mental challenges that include food procurement and identification of individuals within a social system . They also have good spatial discrimination abilities. They are naturally curious and apt to investigate things they have not seen before. Studies have assessed equine intelligence in areas such as problem solving , speed of learning, and memory . Horses excel at simple learning, but also are able to use more advanced cognitive abilities that involve categorization and concept learning . They can learn using habituation , desensitization , classical conditioning , and operant conditioning , and positive and negative reinforcement . One study has indicated that horses can differentiate between "more or less" if

2254-453: A particular enzyme is expressed at high levels, the organism may produce more of that enzyme and exhibit a particular trait as a result. On the other hand, if the gene is expressed at low levels, the organism may produce less of the enzyme and exhibit a different trait. Gene expression is regulated at various levels and thus each level can affect certain phenotypes, including transcriptional and post-transcriptional regulation. Changes in

2352-479: A pony as a term of endearment . For many forms of competition, the official definition of a pony is a horse that measures less than 14.2  hands (58 inches, 147 cm) at the withers . Standard horses are 14.2 or taller. The International Federation for Equestrian Sports defines the official cutoff point at 148 centimetres (58.3 in; 14.2 hands) without shoes and 149 centimetres (58.66 in; 14. 2 + 1 ⁄ 2 hands) with shoes, though allows

2450-589: A precocial species, and foals are capable of standing and running within a short time following birth. Foals are usually born in the spring. The estrous cycle of a mare occurs roughly every 19–22 days and occurs from early spring into autumn. Most mares enter an anestrus period during the winter and thus do not cycle in this period. Foals are generally weaned from their mothers between four and six months of age. Horses, particularly colts, are sometimes physically capable of reproduction at about 18 months, but domesticated horses are rarely allowed to breed before

2548-477: A predominantly white hair coat and pink skin, a fairly rare occurrence. Different and unrelated genetic factors can produce white coat colors in horses, including several different alleles of dominant white and the sabino-1 gene . However, there are no " albino " horses, defined as having both pink skin and red eyes. Gestation lasts approximately 340 days, with an average range 320–370 days, and usually results in one foal ; twins are rare. Horses are

2646-451: 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, 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

2744-505: Is adequate healthy food. All horses move naturally with four basic gaits : Besides these basic gaits, some horses perform a two-beat pace , instead of the trot. There also are several four-beat ' ambling ' gaits that are approximately the speed of a trot or pace, though smoother to ride. These include the lateral rack , running walk , and tölt as well as the diagonal fox trot . Ambling gaits are often genetic in some breeds, known collectively as gaited horses . These horses replace

2842-418: Is also sometimes used to describe a full-sized horse in a humorous or affectionate sense. The United States Pony Club defines "pony" to be any mount that is ridden by a member regardless of its breed or size. Persons up to 25 years old are eligible for membership, and some of the members' "ponies" actually are full-size horses. Horse at least 48 published The horse ( Equus ferus caballus )

2940-463: Is found growing in two different habitats in Sweden. One habitat is rocky, sea-side cliffs , where the plants are bushy with broad leaves and expanded inflorescences ; the other is among sand dunes where the plants grow prostrate with narrow leaves and compact inflorescences. These habitats alternate along the coast of Sweden and the habitat that the seeds of Hieracium umbellatum land in, determine

3038-416: Is in the nostrils and nasal cavity, which analyze a wide range of odors. The second, located under the nasal cavity, are the vomeronasal organs , also called Jacobson's organs. These have a separate nerve pathway to the brain and appear to primarily analyze pheromones . A horse's hearing is good, and the pinna of each ear can rotate up to 180°, giving the potential for 360° hearing without having to move

Pony - Misplaced Pages Continue

3136-410: Is measured at the highest point of the withers , where the neck meets the back . 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 often stated in units of hands and inches: one hand is equal to 4 inches (101.6 mm). The height is expressed as

3234-417: Is one of the largest of any land mammal. Horses are lateral-eyed, meaning that their eyes are positioned on the sides of their heads. This means that horses have a range of vision of more than 350°, with approximately 65° of this being binocular vision and the remaining 285° monocular vision . Horses have excellent day and night vision , but they have two-color, or dichromatic vision ; their color vision

3332-562: Is passed on though the female line) indicate that a large number of wild mares have contributed to modern domestic breeds; in contrast, studies of y-DNA (passed down the male line) suggest that there was possibly just one single male ancestor of all domesticated breeds. Domestication of the horse probably first occurred in the Eurasian steppes with horses of between 13  hands (52 inches, 132 cm) to over 14 hands (56 inches, 142 cm), and as horse domestication spread,

3430-417: Is problematic. A proposed definition for both terms as the "physical totality of all traits of an organism or of one of its subsystems" was put forth by Mahner and Kary in 1997, who argue that although scientists tend to intuitively use these and related terms in a manner that does not impede research, the terms are not well defined and usage of the terms is not consistent. Some usages of the term suggest that

3528-478: Is relevant, but consider that its role is largely explanatory, rather than assisting in the design of experimental tests. Phenotypes are determined by an interaction of genes and the environment, but the mechanism for each gene and phenotype is different. For instance, an albino phenotype may be caused by a mutation in the gene encoding tyrosinase which is a key enzyme in melanin formation. However, exposure to UV radiation can increase melanin production, hence

3626-426: Is somewhat like red-green color blindness in humans, where certain colors, especially red and related colors, appear as a shade of green. Their sense of smell , while much better than that of humans, is not quite as good as that of a dog. It is believed to play a key role in the social interactions of horses as well as detecting other key scents in the environment. Horses have two olfactory centers. The first system

3724-467: Is summed up by the traditional adage, "no foot, no horse". The horse hoof begins with the distal phalanges , the equivalent of the human fingertip or tip of the toe, surrounded by cartilage and other specialized, blood-rich soft tissues such as the laminae . The exterior hoof wall and horn of the sole is made of keratin , the same material as a human fingernail . The result is that a horse, weighing on average 500 kilograms (1,100 lb), travels on

3822-412: Is the hypothesized pre-cellular stage in the evolutionary history of life on earth, in which self-replicating RNA molecules proliferated prior to the evolution of DNA and proteins. The folded three-dimensional physical structure of the first RNA molecule that possessed ribozyme activity promoting replication while avoiding destruction would have been the first phenotype, and the nucleotide sequence of

3920-617: Is usually considered to be a horse and one less than 14.2 hands (58 inches, 147 cm) a pony, but there are many exceptions to the traditional standard. In Australia, ponies are considered to be those under 14 hands (56 inches, 142 cm). For competition in the Western division of the United States Equestrian Federation , the cutoff is 14.1 hands (57 inches, 145 cm). The International Federation for Equestrian Sports ,

4018-520: Is well-developed. The most sensitive areas are around the eyes, ears, and nose. Horses are able to sense contact as subtle as an insect landing anywhere on the body. Horses have an advanced sense of taste, which allows them to sort through fodder and choose what they would most like to eat, and their prehensile lips can easily sort even small grains. Horses generally will not eat poisonous plants, however, there are exceptions; horses will occasionally eat toxic amounts of poisonous plants even when there

Pony - Misplaced Pages Continue

4116-489: The Connemara pony and Australian Pony , are used primarily for riding . Others, such as the Welsh pony , are used for both riding and driving. There is no direct correlation between a horse's size and its inherent athletic ability. Ponies are often distinguished by their phenotype , a stocky body, dense bone, round shape and well-sprung ribs. They have a short head, large eyes and small ears. In addition to being smaller than

4214-489: The Morgan horse , all of which have individual members both over and under 14.2 hands (58 inches, 147 cm). Many horse breeds have some pony characteristics, such as small size, a heavy coat, a thick mane or heavy bone, but are considered to be horses. In cases such as these, there can be considerable debate over whether to call certain breeds "horses" or "ponies." However, individual breed registries usually are

4312-436: The Morgan horse . Horses are able to sleep both standing up and lying down. In an adaptation from life in the wild, horses are able to enter light sleep by using a " stay apparatus " in their legs, allowing them to doze without collapsing. Horses sleep better when in groups because some animals will sleep while others stand guard to watch for predators. A horse kept alone will not sleep well because its instincts are to keep

4410-477: The Trakehner or Hanoverian , developed when European carriage and war horses were crossed with Arabians or Thoroughbreds, producing a riding horse with more refinement than a draft horse, but greater size and milder temperament than a lighter breed. Certain pony breeds with warmblood characteristics have been developed for smaller riders. Warmbloods are considered a "light horse" or "riding horse". Today,

4508-406: The cannon bones (a single equivalent to the human metacarpal or metatarsal bones ) and the proximal phalanges , located where one finds the "knuckles" of a human. A horse also has no muscles in its legs below the knees and hocks, only skin, hair, bone, tendons , ligaments , cartilage , and the assorted specialized tissues that make up the hoof . The critical importance of the feet and legs

4606-466: The gene controlled by the Melanocortin 1 receptor , also known as the "extension gene" or "red factor". Its recessive form is "red" (chestnut) and its dominant form is black. Additional genes control suppression of black color to point coloration that results in a bay , spotting patterns such as pinto or leopard , dilution genes such as palomino or dun , as well as greying , and all

4704-550: The genotype–phenotype distinction in 1911 to make clear the difference between an organism's hereditary material and what that hereditary material produces. The distinction resembles that proposed by August Weismann (1834–1914), who distinguished between germ plasm (heredity) and somatic cells (the body). More recently, in The Selfish Gene (1976), Dawkins distinguished these concepts as replicators and vehicles. Despite its seemingly straightforward definition,

4802-594: The "cold-bloods", such as most draft breeds , are quieter and calmer. Sometimes "hot-bloods" are classified as "light horses" or "riding horses", with the "cold-bloods" classified as "draft horses" or "work horses". "Hot blooded" breeds include " oriental horses " such as the Akhal-Teke , Arabian horse , Barb , and now-extinct Turkoman horse , as well as the Thoroughbred , a breed developed in England from

4900-465: The 20th century, many pony breeds had Arabian and other blood added to make a more refined pony suitable for riding. In many parts of the world, ponies are used as working animals , as pack animals and for pulling various horse-drawn vehicles . They are seen in many different equestrian pursuits. Some breeds, such as the Hackney pony , are primarily used for driving , while other breeds, such as

4998-640: 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: 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 colts and fillies as less than four years old. The height of horses

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5096-678: The ability to thrive on a more limited diet than that of a regular-sized horse, requiring half the hay for their weight as a horse, and often not needing grain at all. However, for the same reason, they are also more vulnerable to laminitis and Cushing's syndrome . They may also have problems with hyperlipemia . Ponies are generally considered intelligent and friendly, though sometimes they also are described as stubborn or cunning. The differences of opinion often result from an individual pony's degree of proper training. Ponies trained by inexperienced individuals, or only ridden by beginners, can turn out to be spoiled because their riders typically lack

5194-456: The age of three, especially females. Horses four years old are considered mature, although the skeleton normally continues to develop until the age of six; maturation also depends on the horse's size, breed, sex, and quality of care. Larger horses have larger bones; therefore, not only do the bones take longer to form bone tissue , but the epiphyseal plates are larger and take longer to convert from cartilage to bone. These plates convert after

5292-460: The arbiters of such debates, weighing the relative horse and pony characteristics of a breed. In some breeds, such as the Welsh pony , the horse-versus-pony controversy is resolved by creating separate divisions for consistently horse-sized animals, such as the "Section D" Welsh Cob . Some horses may be pony height due to environment more than genetics . For example, the Chincoteague pony ,

5390-747: The calm, patient temperament needed to pull a plow or a heavy carriage full of people. They are sometimes nicknamed "gentle giants". Well-known draft breeds include the Belgian and the Clydesdale . Some, like the Percheron , are lighter and livelier, developed to pull carriages or to plow large fields in drier climates. Others, such as the Shire , are slower and more powerful, bred to plow fields with heavy, clay-based soils. The cold-blooded group also includes some pony breeds. " Warmblood " breeds, such as

5488-450: The concept of the phenotype has hidden subtleties. It may seem that anything dependent on the genotype is a phenotype, including molecules such as RNA and proteins . Most molecules and structures coded by the genetic material are not visible in the appearance of an organism, yet they are observable (for example by Western blotting ) and are thus part of the phenotype; human blood groups are an example. It may seem that this goes beyond

5586-517: The context of phenotype prediction. Although a phenotype is the ensemble of observable characteristics displayed by an organism, the word phenome is sometimes used to refer to a collection of traits, while the simultaneous study of such a collection is referred to as phenomics . Phenomics is an important field of study because it can be used to figure out which genomic variants affect phenotypes which then can be used to explain things like health, disease, and evolutionary fitness. Phenomics forms

5684-483: The corresponding amino acid sequence of a gene may change the frequency of guanine - cytosine base pairs ( GC content ). These base pairs have a higher thermal stability ( melting point ) than adenine - thymine , a property that might convey, among organisms living in high-temperature environments, a selective advantage on variants enriched in GC content. Richard Dawkins described a phenotype that included all effects that

5782-469: The day. Therefore, compared to humans, they have a relatively small stomach but very long intestines to facilitate a steady flow of nutrients. A 450-kilogram (990 lb) horse will eat 7 to 11 kilograms (15 to 24 lb) of food per day and, under normal use, drink 38 to 45 litres (8.4 to 9.9 imp gal; 10 to 12 US gal) of water . Horses are not ruminants , having only one stomach, like humans. But unlike humans, they can digest cellulose ,

5880-415: The environment plays a role in this phenotype as well. For most complex phenotypes the precise genetic mechanism remains unknown. For instance, it is largely unclear how genes determine the shape of bones or the human ear. Gene expression plays a crucial role in determining the phenotypes of organisms. The level of gene expression can affect the phenotype of an organism. For example, if a gene that codes for

5978-439: The evolution from genotype to genome to pan-genome , a concept of exploring the relationship ultimately among pan-phenome, pan-genome , and pan- envirome was proposed in 2023. Phenotypic variation (due to underlying heritable genetic variation ) is a fundamental prerequisite for evolution by natural selection . It is the living organism as a whole that contributes (or not) to the next generation, so natural selection affects

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6076-843: The experience base to correct bad habits. Properly trained ponies are appropriate mounts for children who are learning to ride. Larger ponies can be ridden by adults, as ponies are usually strong for their size. For showing purposes, ponies are often grouped into small, medium, and large sizes. Small ponies are 12.2  hands (50 inches, 127 cm) and under, medium ponies are over 12.2 but no taller than 13.2 hands (54 inches, 137 cm), and large ponies are over 13.2 hands (54 inches, 137 cm) but no taller than 14.2 hands (58 inches, 147 cm). The smallest equines are called miniature horses by many of their breeders and breed organizations, rather than ponies, even though they stand smaller than small ponies, usually no taller than 38 inches (97 cm; 9.2 hands ) at

6174-440: The false statement that a "mutation has no phenotype". Behaviors and their consequences are also phenotypes, since behaviors are observable characteristics. Behavioral phenotypes include cognitive, personality, and behavioral patterns. Some behavioral phenotypes may characterize psychiatric disorders or syndromes. A phenome is the set of all traits expressed by a cell , tissue , organ , organism , or species . The term

6272-401: The front of the mouth, adapted to biting off the grass or other vegetation. There are 24 teeth adapted for chewing, the premolars and molars , at the back of the mouth. Stallions and geldings have four additional teeth just behind the incisors, a type of canine teeth called "tushes". Some horses, both male and female, will also develop one to four very small vestigial teeth in front of

6370-541: The genetic structure of a population indirectly via the contribution of phenotypes. Without phenotypic variation, there would be no evolution by natural selection. The interaction between genotype and phenotype has often been conceptualized by the following relationship: A more nuanced version of the relationship is: Genotypes often have much flexibility in the modification and expression of phenotypes; in many organisms these phenotypes are very different under varying environmental conditions. The plant Hieracium umbellatum

6468-507: The head. Noise affects the behavior of horses and certain kinds of noise may contribute to stress—a 2013 study in the UK indicated that stabled horses were calmest in a quiet setting, or if listening to country or classical music, but displayed signs of nervousness when listening to jazz or rock music. This study also recommended keeping music under a volume of 21 decibels . An Australian study found that stabled racehorses listening to talk radio had

6566-437: The incisors show changes as the horse ages; they develop a distinct wear pattern, changes in tooth shape, and changes in the angle at which the chewing surfaces meet. This allows a very rough estimate of a horse's age, although diet and veterinary care can also affect the rate of tooth wear. Horses are herbivores with a digestive system adapted to a forage diet of grasses and other plant material, consumed steadily throughout

6664-721: The individual. Large-scale genetic screens can identify the genes or mutations that affect the phenotype of an organism. Analyzing the phenotypes of mutant genes can also aid in determining gene function. Most genetic screens have used microorganisms, in which genes can be easily deleted. For instance, nearly all genes have been deleted in E. coli and many other bacteria , but also in several eukaryotic model organisms such as baker's yeast and fission yeast . Among other discoveries, such studies have revealed lists of essential genes . More recently, large-scale phenotypic screens have also been used in animals, e.g. to study lesser understood phenotypes such as behavior . In one screen,

6762-626: The levels of gene expression can be influenced by a variety of factors, such as environmental conditions, genetic variations, and epigenetic modifications. These modifications can be influenced by environmental factors such as diet, stress, and exposure to toxins, and can have a significant impact on an individual's phenotype. Some phenotypes may be the result of changes in gene expression due to these factors, rather than changes in genotype. An experiment involving machine learning methods utilizing gene expressions measured from RNA sequencing found that they can contain enough signal to separate individuals in

6860-419: The male descendants of the original stallion went on to be bred with local wild mares. Domesticated ponies of all breeds originally developed mainly from the need for a working animal that could fulfill specific local draft and transportation needs while surviving in harsh environments. The usefulness of the pony was noted by farmers who observed that a pony could outperform a draft horse on small farms. By

6958-435: The molars, known as "wolf" teeth, which are generally removed because they can interfere with the bit . There is an empty interdental space between the incisors and the molars where the bit rests directly on the gums, or "bars" of the horse's mouth when the horse is bridled . An estimate of a horse's age can be made from looking at its teeth. The teeth continue to erupt throughout life and are worn down by grazing. Therefore,

7056-1030: The number of full hands, followed by a point , then the number of additional inches, and ending with the abbreviation "h" or "hh" (for "hands high"). Thus, a horse described as "15.2 h" is 15 hands plus 2 inches, for a total of 62 inches (157.5 cm) in height. The size of horses varies by breed, but also is influenced by nutrition . Light-riding horses usually range in height from 14 to 16 hands (56 to 64 inches, 142 to 163 cm) and can weigh from 380 to 550 kilograms (840 to 1,210 lb). Larger-riding horses usually start at about 15.2 hands (62 inches, 157 cm) and often are as tall as 17 hands (68 inches, 173 cm), weighing from 500 to 600 kilograms (1,100 to 1,320 lb). Heavy or draft horses are usually at least 16 hands (64 inches, 163 cm) high and can be as tall as 18 hands (72 inches, 183 cm) high. They can weigh from about 700 to 1,000 kilograms (1,540 to 2,200 lb). The largest horse in recorded history

7154-619: The number of putative mutants (see table for details). Putative mutants are then tested for heritability in order to help determine the inheritance pattern as well as map out the mutations. Once they have been mapped out, cloned, and identified, it can be determined whether a mutation represents a new gene or not. These experiments showed that mutations in the rhodopsin gene affected vision and can even cause retinal degeneration in mice. The same amino acid change causes human familial blindness , showing how phenotyping in animals can inform medical diagnostics and possibly therapy. The RNA world

7252-511: The old French poulenet , meaning foal , a young, immature horse. In modern use, some organizations may define a pony as a mature horse below a certain height at the withers; this may vary from about 142 cm (14.0  h ) to nearly 150 cm (14.3 h). (Note: 14.3 hands means 14 hands and 3 inches, i.e. decimally 14.75 hands.) Some people classify an animal as either horse or pony from its pedigree and phenotype , no matter what its height. A full-sized horse may sometimes even be called

7350-555: The older oriental breeds. Hot bloods tend to be spirited, bold, and learn quickly. They are bred for agility and speed. They tend to be physically refined—thin-skinned, slim, and long-legged. The original oriental breeds were brought to Europe from the Middle East and North Africa when European breeders wished to infuse these traits into racing and light cavalry horses. Muscular, heavy draft horses are known as "cold bloods." They are bred not only for strength, but also to have

7448-411: The original intentions of the concept with its focus on the (living) organism in itself. Either way, the term phenotype includes inherent traits or characteristics that are observable or traits that can be made visible by some technical procedure. The term "phenotype" has sometimes been incorrectly used as a shorthand for the phenotypic difference between a mutant and its wild type , which would lead to

7546-435: The other factors that create the many possible coat colors found in horses. Horses that have a white coat color are often mislabeled; a horse that looks "white" is usually a middle-aged or older gray . Grays are born a darker shade, get lighter as they age, but usually keep black skin underneath their white hair coat (with the exception of pink skin under white markings ). The only horses properly called white are born with

7644-605: The other parts of the bones, and are crucial to development. Depending on maturity, breed, and work expected, horses are usually put under saddle and trained to be ridden between the ages of two and four. Although Thoroughbred race horses are put on the track as young as the age of two in some countries, horses specifically bred for sports such as dressage are generally not put under saddle until they are three or four years old, because their bones and muscles are not solidly developed. For endurance riding competition, horses are not deemed mature enough to compete until they are

7742-438: The phenome of a given organism is best understood as a kind of matrix of data representing physical manifestation of phenotype. For example, discussions led by A. Varki among those who had used the term up to 2003 suggested the following definition: "The body of information describing an organism's phenotypes, under the influences of genetic and environmental factors". Another team of researchers characterize "the human phenome [as]

7840-531: The phenotype that grows. An example of random variation in Drosophila flies is the number of ommatidia , which may vary (randomly) between left and right eyes in a single individual as much as they do between different genotypes overall, or between clones raised in different environments. The concept of phenotype can be extended to variations below the level of the gene that affect an organism's fitness. For example, silent mutations that do not change

7938-570: The quantity involved is less than four. Domesticated horses may face greater mental challenges than wild horses, because they live in artificial environments that prevent instinctive behavior whilst also learning tasks that are not natural. Horses are animals of habit that respond well to regimentation, and respond best when the same routines and techniques are used consistently. One trainer believes that "intelligent" horses are reflections of intelligent trainers who effectively use response conditioning techniques and positive reinforcement to train in

8036-428: The role of mutations in mice were studied in areas such as learning and memory , circadian rhythmicity , vision, responses to stress and response to psychostimulants . This experiment involved the progeny of mice treated with ENU , or N-ethyl-N-nitrosourea, which is a potent mutagen that causes point mutations . The mice were phenotypically screened for alterations in the different behavioral domains in order to find

8134-496: The same animals as horses. The distinction between a horse and pony is commonly drawn on the basis of height, especially for competition purposes. However, height alone is not dispositive; the difference between horses and ponies may also include aspects of phenotype , including conformation and temperament. The traditional standard for height of a horse or a pony at maturity is 14.2 hands (58 inches, 147 cm). An animal 14.2 hands (58 inches, 147 cm) or over

8232-507: The same bones as would a human on tiptoe. For the protection of the hoof under certain conditions, some horses have horseshoes placed on their feet by a professional farrier . The hoof continually grows, and in most domesticated horses needs to be trimmed (and horseshoes reset, if used) every five to eight weeks, though the hooves of horses in the wild wear down and regrow at a rate suitable for their terrain. Horses are adapted to grazing . In an adult horse, there are 12  incisors at

8330-472: The same color may be distinguished from one another by white markings , which, along with various spotting patterns, are inherited separately from coat color. Many genes that create horse coat colors and patterns have been identified. Current genetic tests can identify at least 13 different alleles influencing coat color, and research continues to discover new genes linked to specific traits. The basic coat colors of chestnut and black are determined by

8428-470: The style that best fits with an individual animal's natural inclinations. Horses are mammals . As such, they are warm-blooded , or endothermic creatures, as opposed to cold-blooded, or poikilothermic animals. However, these words have developed a separate meaning in the context of equine terminology, used to describe temperament, not body temperature . For example, the " hot-bloods ", such as many race horses , exhibit more sensitivity and energy, while

8526-513: 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. 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. Horses are adapted to run , allowing them to quickly escape predators, and possess

8624-558: The term "Warmblood" refers to a specific subset of sport horse breeds that are used for competition in dressage and show jumping . Strictly speaking, the term " warm blood " refers to any cross between cold-blooded and hot-blooded breeds. Examples include breeds such as the Irish Draught or the Cleveland Bay . The term was once used to refer to breeds of light riding horse other than Thoroughbreds or Arabians, such as

8722-541: The tradition of referring to their horses as "ponies", when speaking in English, even though many of the Mustang horses they used in the 19th century were close to or over 14.2 hands (58 inches, 147 cm), and most horses owned and bred by Native peoples today are of full horse height. Non-racing horses at racetracks that are used to lead the racehorses, ponying them, are called "pony horses". The term "pony"

8820-788: The trot with one of the ambling gaits. Horses are prey animals with a strong fight-or-flight response . Their first reaction to a threat is to startle and usually flee, although they will stand their ground and defend themselves when flight is impossible or if their young are threatened. They also tend to be curious; when startled, they will often hesitate an instant to ascertain the cause of their fright, and may not always flee from something that they perceive as non-threatening. Most light horse riding breeds were developed for speed, agility, alertness and endurance; natural qualities that extend from their wild ancestors. However, through selective breeding, some breeds of horses are quite docile, particularly certain draft horses. Horses are herd animals , with

8918-401: The urine of pregnant mares . Humans provide domesticated horses with food, water, and shelter, as well as attention from specialists such as veterinarians and farriers . Depending on breed, management and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and, occasionally, beyond. The oldest verifiable record

9016-455: The withers. However, there are also miniature pony breeds. Some horse breeds are not defined as ponies, even when they have some animals that measure under 14.2  hands (58 inches, 147 cm). This is usually due to body build, traditional uses and overall physiology. Breeds that are considered horses regardless of height include the Arabian horse , American Quarter Horse and

9114-1085: The world governing body for horse sport, uses metric measurements and defines a pony as being any horse measuring less than 148 centimetres (58.27 in) at the withers without shoes, which is just over 14.2 hands (58 inches, 147 cm), and 149 centimetres (58.66 in; 14. 2 + 1 ⁄ 2 hands), with shoes. Height is not the sole criterion for distinguishing horses from ponies. Breed registries for horses that typically produce individuals both under and over 14.2 hands (58 inches, 147 cm) consider all animals of that breed to be horses regardless of their height. Conversely, some pony breeds may have features in common with horses, and individual animals may occasionally mature at over 14.2 hands (58 inches, 147 cm), but are still considered to be ponies. Ponies often exhibit thicker manes, tails, and overall coat. They also have proportionally shorter legs, wider barrels, heavier bone, shorter and thicker necks, and short heads with broad foreheads. They may have calmer temperaments than horses and also

9212-569: 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 , entertainment, and therapy . Horses were historically 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 , milk , hide , hair , bone, and pharmaceuticals extracted from

9310-408: Was sequenced in 2007. It contains 2.7 billion DNA base pairs , which is larger than the dog genome , but smaller than the human genome or the bovine genome . The map is available to researchers. Horses exhibit a diverse array of coat colors and distinctive markings , described by a specialized vocabulary. Often, a horse is classified first by its coat color, before breed or sex. Horses of

9408-550: Was " Old Billy ", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had been 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

9506-405: Was first used by Davis in 1949, "We here propose the name phenome for the sum total of extragenic, non-autoreproductive portions of the cell, whether cytoplasmic or nuclear. The phenome would be the material basis of the phenotype, just as the genome is the material basis of the genotype ." Although phenome has been in use for many years, the distinction between the use of phenome and phenotype

9604-451: Was probably a Shire horse named Mammoth , who was born in 1848. He stood 21.2 ⁄ 4  hands (86.25 inches, 219 cm) high and his peak weight was estimated at 1,524 kilograms (3,360 lb). The record holder for the smallest horse ever is Thumbelina , a fully mature miniature horse affected by dwarfism . She was 43 centimetres; 4.1 hands (17 in) tall and weighed 26 kg (57 lb). Ponies are taxonomically

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