Selective breeding is the process of breeding plants Plant breeding is the art and science of changing the genetics of plants for the benefit of humankind. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular techniques and animals Animal breeding is a branch of animal science that addresses the evaluation of the genetic value (estimated breeding value, EBV) of domestic livestock. Selecting animals for breeding with superior EBV in growth rate, egg, meat, milk, or wool production, or have other desirable traits has revolutionized agricultural livestock production throughout for particular genetic traits. Typically, strains which are selectively bred are domesticated Domestication or taming refers to the process whereby a population of animals or plants, through a process of selection, becomes accustomed to human provision and control. A defining characteristic of domestication is artificial selection by humans. Some species such as the Asian Elephant, numerous members of which which have for many centuries, and the breeding is sometimes done by a professional breeder This might be as a farmer, agriculturalist, or hobbyist, and can be practiced on a large or small scale, for food, fun, or profit. Bred animals are known as breeds A breed is a group of domestic animals with a homogeneous appearance, behavior, and other characteristics that distinguish it from other animals of the same species. When bred together, animals of the same breed pass on these uniform traits to their offspring, and this ability—known as "breeding true"—is a definitive requirement for, while bred plants are known as varieties In botanical nomenclature, variety is a taxonomic rank below that of species: As such, it gets a ternary name, cultigens A cultigen is a plant that has been deliberately altered or selected by humans; it is the result of artificial selection. These "man-made" or anthropogenic plants are, for the most part, plants of commerce that are used in horticulture, agriculture and forestry, or cultivars A cultivar is a cultivated plant that has been selected and given a unique name because of its decorative or useful characteristics[clarification needed]; it is usually distinct from similar plants and when propagated it retains those characteristics. The cross of animals results in what is called a crossbreed A crossbreed or crossbred usually refers to an animal with purebred parents of two different breeds, varieties, or populations. Crossbreeding refers to the process of breeding such an animal, often with the intention of creating offspring that share the traits of both parent lineages, or producing an animal with hybrid vigor. While crossbreeding and crossbred plants are called hybrids In biology, hybrid has two meanings. The first meaning is the result of interbreeding between two animals or plants of different taxa. Hybrids between different subspecies within a species are known as intra-specific hybrids. Hybrids between different species within the same genus (such as between lions and tigers) are sometimes known as. The term selective breeding is synonymous with artificial selection Artificial selection describes intentional breeding for certain traits, or combination of traits. It was defined by Charles Darwin in contrast to natural selection, in which the differential reproduction of organisms with certain traits is attributed to improved survival or reproductive ability (“Darwinian fitness”) and the creation of new.

In animal breeding techniques such as inbreeding Inbreeding is breeding between close relatives, whether plant or animal. If practiced repeatedly, it can lead to an increase in homozygosity of a population. A higher frequency of recessive, deleterious traits in homozygous form in a population can, over time, result in inbreeding depression. This may occur when inbred individuals exhibit reduced, linebreeding Linebreeding is a form of inbreeding practiced by some animal breeders to "fix" desirable traits in a breed of animal, without as high a risk of producing undesirable traits that may occur with close inbreeding and outcrossing Outcrossing is the practice of introducing unrelated genetic material into a breeding line. It increases genetic diversity, thus reducing the probability of all individuals being subject to disease or reducing genetic abnormalities. It actually can serve to increase the number of individuals who carry a disease recessively are utilized. In plant breeding similar methods are used. Charles Darwin Charles Robert Darwin FRS was an English naturalist[I] who realised and presented compelling evidence that all species of life have evolved over time from common ancestors, through the process he called natural selection. The fact that evolution occurs became accepted by the scientific community and much of the general public in his lifetime, discussed how selective breeding had been successful in producing change over time in his book, Origin of Species Charles Darwin's On the Origin of Species, published 24 November 1859, is a seminal work of scientific literature considered to be the foundation of evolutionary biology. Its full title was On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. For the sixth edition of 1872, the. The first chapter of the book discusses selective breeding and domestication Domestication or taming refers to the process whereby a population of animals or plants, through a process of selection, becomes accustomed to human provision and control. A defining characteristic of domestication is artificial selection by humans. Some species such as the Asian Elephant, numerous members of which which have for many centuries of such animals as pigeons Pigeons and doves constitute the family Columbidae within the order Columbiformes, which include some 300 species of near passerine birds. In general parlance the terms "dove" and "pigeon" are used somewhat interchangeably. In ornithological practice, there is a tendency for "dove" to be used for smaller species and &, dogs The dog is a domesticated subspecies of the Gray Wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history. Amongst canine enthusiasts, the word "dog" may also mean the male of a and cattle Cattle, colloquially referred to as cows, are domesticated ungulates, a member of the subfamily Bovinae of the family Bovidae. They are raised as livestock for meat , dairy products (milk), leather and as draft animals (pulling carts, plows and the like). In some countries, such as India, they are honored in religious ceremonies and revered. It is. Selective breeding was used by Darwin as a springboard to introduce the theory of natural selection Natural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations. It is a key mechanism of evolution, and to support it.[1]

Contents

Animal breeding

Main article: Animal breeding Animal breeding is a branch of animal science that addresses the evaluation of the genetic value (estimated breeding value, EBV) of domestic livestock. Selecting animals for breeding with superior EBV in growth rate, egg, meat, milk, or wool production, or have other desirable traits has revolutionized agricultural livestock production throughout

Animals with homogeneous appearance, behavior, and other characteristics are known as particular breeds, and they are bred through culling Culling is the process of removing animals from a group based on specific criteria. This is done in order to either reinforce certain desirable characteristics or to remove certain undesirable characteristics from the group. For livestock and wildlife, the process of culling usually implies the killing of animals with undesirable characteristics particular traits and selecting for others. Purebred Purebreds, also called purebreeds, are cultivated varieties or cultivars of an animal species, achieved through the process of selective breeding. When the lineage of a purebred animal is recorded, that animal is said to be pedigreed animals have a single, recognizable breed, and purebreds with recorded lineage are called pedigreed. Crossbreeds A crossbreed or crossbred usually refers to an animal with purebred parents of two different breeds, varieties, or populations. Crossbreeding refers to the process of breeding such an animal, often with the intention of creating offspring that share the traits of both parent lineages, or producing an animal with hybrid vigor. While crossbreeding are a mix of two purebreds, while mixed breeds are a mix of several breeds, often unknown. Animal breeding begins with breeding stock, a group of animals used for purpose of planned breeding. When individuals are looking to breed animals, they look for certain valuable traits in purebred stock for a certain purpose, or may intend to use some type of crossbreeding to produce a new type of stock with different, and presumably superior abilities in a given area of endeavor. For example, to breed chickens, a typical breeder intends to receive eggs, meat, and new, young birds for further reproduction. Thus the breeder has to study different breeds and types of chickens and analyze what can be expected from a certain set of characteristics before he or she starts breeding them. Accordingly, when purchasing initial breeding stock, the breeder seeks a group of birds that will most closely fit the purpose intended.

Purebred breeding aims to establish and maintain stable traits, that animals will pass to the next generation. By "breeding the best to the best," employing a certain degree of inbreeding Inbreeding is breeding between close relatives, whether plant or animal. If practiced repeatedly, it can lead to an increase in homozygosity of a population. A higher frequency of recessive, deleterious traits in homozygous form in a population can, over time, result in inbreeding depression. This may occur when inbred individuals exhibit reduced, considerable culling, and selection for "superior" qualities, one could develop a bloodline superior in certain respects to the original base stock. Such animals can be recorded with a breed registry A breed registry, also known as a stud book or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders when they are still young. The terms "stud book" and "register" are also used to refer to, the organization that maintains pedigrees and/or stud books A breed registry, also known as a stud book or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders when they are still young. The terms "stud book" and "register" are also used to refer to.

The observable phenomenon of hybrid vigor Heterosis is a term used in genetics and selective breeding. The term heterosis, also known as hybrid vigor or outbreeding enhancement, describes the increased strength of different characteristics in hybrids; the possibility to obtain a genetically superior individual by combining the virtues of its parents stands in contrast to the notion of breed purity. However, on the other hand, indiscriminate breeding of crossbred or hybrid In biology, hybrid has two meanings. The first meaning is the result of interbreeding between two animals or plants of different taxa. Hybrids between different subspecies within a species are known as intra-specific hybrids. Hybrids between different species within the same genus (such as between lions and tigers) are sometimes known as animals may also result in degradation of quality.[citation needed]

Plant breeding

Main article: Plant breeding Plant breeding is the art and science of changing the genetics of plants for the benefit of humankind. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular techniques

Plant breeding has been used for thousands of years, and began with the domestication of wild plants into uniform and predictable agricultural cultigens A cultigen is a plant that has been deliberately altered or selected by humans; it is the result of artificial selection. These "man-made" or anthropogenic plants are, for the most part, plants of commerce that are used in horticulture, agriculture and forestry. High-yielding varieties High-yielding varieties are any of a group of genetically enhanced cultivars of crops such as rice, maize and wheat that have an increased growth rate, an increased percentage of usable plant parts or an increased resistance against crop diseases. Those crops formed the basis for the Green Revolution. In general, they require a higher level of have been particularly important in agriculture.

Selective plant breeding is also used in research to produce transgenic A genetically modified organism or genetically engineered organism (GEO) is an organism whose genetic material has been altered using genetic engineering techniques. These techniques, generally known as recombinant DNA technology, use DNA molecules from different sources, which are combined into one molecule to create a new set of genes. This DNA animals that breed "true" (i.e. are homozygous Zygosity refers to the similarity or dissimilarity of the DNA sequences in specific coding segments, or genes, on the homologous chromosomes of a zygote, or fertilized egg. The DNA sequence of any gene can vary among individuals in the population. The various forms of a gene are called alleles, and diploid organisms generally have two alleles for) for artificially inserted or deleted A gene knockout is a genetic technique in which an organism is engineered to carry genes that have been made inoperative (have been "knocked out" of the organism). This is done for research purposes. Also known as knockout organisms or simply knockouts, they are used in learning about a gene that has been sequenced, but which has an genes.[citation needed]

See also

References

  1. ^ *Darwin Charles Robert Darwin FRS was an English naturalist[I] who realised and presented compelling evidence that all species of life have evolved over time from common ancestors, through the process he called natural selection. The fact that evolution occurs became accepted by the scientific community and much of the general public in his lifetime,, Charles (2004). The Origin of Species. London: CRW Publishing Limited. ISBN 1904633781.

External links

Categories: Biotechnology Biotechnology is technology based on biology, especially when used in agriculture, food science, medicine, and Genetic engineering | Breeding

 

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