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43-572: The Asturcón is an ancient Spanish breed of small horse or pony from the autonomous region of Asturias in the northern part of the country. It has been documented since Roman times: it has an unusual ambling gait , which was described by Pliny the Elder in his Naturalis Historia . It is of Celtic type, and shows similarity to the Pottok and Losino of Spain, the Garrano of Portugal, and

86-454: A breed registry . The concept is somewhat flexible in horses, as open stud books are created for recording pedigrees of horse breeds that are not yet fully true-breeding. Registries are considered the authority as to whether a given breed is listed as a "horse" or a "pony". There are also a number of " color breed ", sport horse , and gaited horse registries for horses with various phenotypes or other traits, which admit any animal fitting

129-484: 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

172-513: A breed is described as a "pony" by the breed standard or principal breed registry, it is listed in this section, even if some individuals have horse characteristics. All other breeds are listed in the § Horse breeds section above. (Because of this designation by the preference of a given breed registry, most miniature horse breeds are listed as "horses", not ponies.) There are some registries that accept horses (and sometimes ponies and mules) of almost any breed or type for registration. Color

215-518: 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

258-430: A given set of physical characteristics, even if there the trait is not a true-breeding characteristic. Other recording entities or specialty organizations may recognize horses from multiple breeds, or are recording designer crossbreds . Such animals may be classified here as a breed, a crossbreed, or a "type”, depending on the stage of breed recognition. In some cultures and for some competition-sanctioning organizations,

301-428: A horse that normally matures less than about 145 cm or 14.2  hands (58 inches, 147 cm) when fully grown may be classified as a " pony ". However, unless the principal breed registry or breed standard describes the breed as a pony, it is listed in this section, even if some or all representatives are small or have some pony characteristics. Ponies are listed in the § Pony breeds section below. If

344-529: 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

387-537: 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

430-453: 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

473-483: Is a recording method or means of studbook selection for certain types to allow them to be licensed for breeding. Horses of a given type may be registered as one of several different recognized breeds, or a grouping may include horses that are of no particular pedigree but meet a certain standard of appearance or use. Prior to approximately the 13th century, few pedigrees were written down, and horses were classified by physical type or use. Thus, many terms for Horses in

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516-420: Is either the only criterion for registration or the primary criterion. These are called " color breeds ", because unlike "true" horse breeds, there are few other physical requirements, nor is the stud book limited in any fashion. As a general rule, the color also does not always breed on (in some cases due to genetic impossibility), and offspring without the stated color are usually not eligible for recording with

559-463: 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

602-417: 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

645-478: 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

688-412: 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

731-479: Is the set of observable characteristics or traits of an organism . The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properties, its behavior , and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code (its genotype ) and the influence of environmental factors. Both factors may interact, further affecting

774-469: Is usually in the range 130–147 cm , and never exceeds 147 cm . With an average weight of some 300 kg In the early twenty-first century the only coat colour admitted for registration in the stud-book was black , with no marking other than a small frontal star . There was a small population of bay Asturian horses of Celtic type, but they were not registered in the Asturcón stud-book. In

817-537: The Dartmoor , Exmoor , Fell , Highland , Shetland and Welsh breeds of the British Isles. The Asturcón has been known and described since Roman times; it is mentioned in an epigram of Martial , and by Pliny the Elder in his Naturalis Historia , where he describes its characteristic ambling gait . The Latin word asturco was later used for other similar small horses with ambling gait. At about

860-568: The breed standard published in early 2012 by the Government of Asturias , the permitted coat colours are black, bay and chestnut , still with no marking other than a small star. List of horse breeds While there is no scientifically accepted definition of the term "breed", a breed is generally defined as having distinct true-breeding characteristics over a number of generations. Its members may be called purebred . In most cases, bloodlines of horse breeds are recorded with

903-550: 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,

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946-516: The Middle Ages did not refer to breeds as we know them today, but rather described appearance or purpose. These terms included: Many breeds of horse have become extinct , either because they have died out, or because they have been absorbed into another breed: Phenotype In genetics , the phenotype (from Ancient Greek φαίνω ( phaínō )  'to appear, show' and τύπος ( túpos )  'mark, type')

989-480: The breed or type categories are listed here. This list does not include organizations that record horses strictly for competition purposes. A "type" of horse is not a breed but is used here to categorize groups of horses or horse breeds that are similar in appearance ( phenotype ) or use. A type usually has no breed registry , and often encompasses several breeds. However, in some nations, particularly in Europe, there

1032-678: The color breed registry. There are breeds that have color that usually breeds "true" as well as distinctive physical characteristics and a limited stud book. These horses are true breeds that have a preferred color, not color breeds, and include the Friesian horse , the Cleveland Bay , the Appaloosa , and the American Paint Horse . The best-known "color breed" registries that accept horses from many different breeds are for

1075-450: 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

1118-517: 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

1161-483: 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

1204-415: 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

1247-439: 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

1290-440: 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

1333-414: The following colors: The distinction is hotly debated between a standardized breed, a developing breed with an open studbook , a registry of recognized crossbred horses, and a designer crossbred . For the purposes of this list, certain groups of horses that have an organization or registry that records individual animals for breeding purposes, at least in some nations, but does not clearly fall to either

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1376-541: 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

1419-721: 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,

1462-626: 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

1505-619: 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

1548-411: 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

1591-438: 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]

1634-531: 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

1677-590: The phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic . A well-documented example of polymorphism is Labrador Retriever coloring ; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book The Extended Phenotype suggested that one can regard bird nests and other built structures such as caddisfly larva cases and beaver dams as "extended phenotypes". Wilhelm Johannsen proposed

1720-428: 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

1763-542: The time of the Spanish Civil War , the population of the Asturcón separated into two distinct parts, one in the sierras of Sueve and La Vita, and the other further to the west, in the sierras of El Palo , La Bobia  [ es ] and Tineo . The two populations are genetically distinct. A breeders' association , the Asociación de Criadores de Ponis de Raza Asturcón , was formed in 1987; at

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1806-449: The time there were 23 mares registered in the stud-book . At the end of 2003, there were 1181 head registered, in the hands of 94 breeders. In 2007 the Asturcón was listed by the FAO as "endangered-maintained". The Asturcón is thought to have given rise to the extinct Irish Hobby , and has been used in attempts to re-create that breed. The Asturcón is a small horse: height at the withers

1849-405: 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

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