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Introgressive Hybridization
Introgression, also known as introgressive hybridization, in genetics is the transfer of genetic material from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species. Introgression is a long-term process, even when artificial; it may take many hybrid generations before significant backcrossing occurs. This process is distinct from most forms of gene flow in that it occurs between two populations of different species, rather than two populations of the same species. Introgression also differs from simple hybridization. Simple hybridization results in a relatively even mixture; gene and allele frequencies in the first generation will be a uniform mix of two parental species, such as that observed in mules. Introgression, on the other hand, results in a complex, highly variable mixture of genes, and may only involve a minimal percentage of the donor genome. Definition Introgression or introgressive hybr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid PNGT
Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two different genetic parent strains * Hybrid (particle physics), a valence quark-antiquark pair and one or more gluons * Hybrid solar eclipse, a rare solar eclipse type Technology Transportation * Hybrid vehicle, a vehicle using more than one power source or an engine sourced from a different chassis ** Hybrid electric vehicle, a vehicle using both internal combustion and electric power sources *** Plug-in hybrid, whose battery can be recharged by a charging cable * Hybrid bicycle, a bicycle with features of road and mountain bikes * Hybrid train, a locomotive, railcar, or train that uses an onboard rechargeable energy storage system * Hybrid motorcycle, a motorcycle built using components from more than one original-manufacturer products, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Biology And Evolution
''Molecular Biology and Evolution'' is a monthly peer-reviewed scientific journal published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. It publishes work in the intersection of molecular biology and evolutionary biology. The founding editors-in-chief were Walter Fitch and Masatoshi Nei; the present editor-in-chief is Sudhir Kumar. According to the ''Journal Citation Reports'', the journal has a 2017 Impact Factor of 10.217, a 2018 Impact Factor of 14.797, a 2019 Impact Factor of 11.062, and a 2021 Impact Factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 8.800 References External links * Molecular and cellular biology journals Evolutionary biology journals English-language journals Monthly journals Oxford Univers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated ( S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities. The history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Sheep, goats, pigs and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture. The major agricultural products can be broadly grouped into foods, fibers, fuels, and raw materials (such as rubber). Food classes include cereals (grains), vegetables, fruits, cooking oils, meat, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Troglomorphism
Troglomorphism is the morphological adaptation of an animal to living in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and frequently with attenuated bodies and/or appendages. The terms troglobitic, stygobitic, stygofauna, troglofauna, and hypogean or hypogeic, are often used for cave-dwelling organisms. A 2012 study by a team from the National University of Singapore found that reductive changes in freshwater cave crabs evolved at the same rate as constructive changes. This shows that both selection and evolution have a role in advancing reductive changes (e.g smaller eyes) and constructive changes (e.g larger claws), making troglomorphic adaptations subject to strong factors that affect an organism's morphology. Troglomorphism occurs in molluscs, velvet worms, arachnids, myriapods, crustaceans, insects, fish, amphibians (notably cave salamanders) and reptiles. To date no mammals or birds have been found to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astroblepus
''Astroblepus'' is a genus of fish in the family Astroblepidae found in South America and Panama. This genus is the only member of its family. These catfishes are primarily found in torrential streams in the Andean area. ''Astroblepus pholeter'' and ''A. riberae'' are troglobites adapted to living in subterranean water systems. These species are typically small, less than . The largest species reaches . These fish have suckermouths like those of loricariids. They have two pairs of barbels, maxillary and nasal. The dorsal fin spine lacks a locking mechanism. These fish also have odontodes, tiny teeth on their skin. All species exhibit a conical, pointy type on their fin rays like that found in other loricarioids; other species also exhibit a blunt type that is only found on their skin. Some of these fish are able to live in high altitude and climb the faces of waterfalls. Their climbing ability comes from specially developed pelvic fins, as well as their suckermouths. In th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bordered by the state of Texas to the west, Arkansas to the north, Mississippi to the east, and the Gulf of Mexico to the south. A large part of its eastern boundary is demarcated by the Mississippi River. Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska and its boroughs). The state's capital is Baton Rouge, and its largest city is New Orleans, with a population of roughly 383,000 people. Some Louisiana urban environments have a multicultural, multilingual heritage, being so strongly influenced by a mixture of 18th century Louisiana French, Dominican Creole, Spanish, French Canadian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iris (plant)
''Iris'' is a flowering plant genus of 310 accepted species with showy flowers. As well as being the scientific name, ''iris'' is also widely used as a common name for all ''Iris'' species, as well as some belonging to other closely related genera. A common name for some species is 'flags', while the plants of the subgenus '' Scorpiris'' are widely known as ' junos', particularly in horticulture. It is a popular garden flower. The often-segregated, monotypic genera ''Belamcanda'' (blackberry lily, ''I. domestica''), ''Hermodactylus'' (snake's head iris, ''I. tuberosa''), and ''Pardanthopsis'' (vesper iris, '' I. dichotoma'') are currently included in ''Iris''. Three Iris varieties are used in the Iris flower data set outlined by Ronald Fisher in his 1936 paper ''The use of multiple measurements in taxonomic problems'' as an example of linear discriminant analysis. Description Irises are perennial plants, growing from creeping rhizomes (rhizomatous irises) or, in drier cli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canid Hybrid
Canid hybrids are the result of interbreeding between the species of the genus '' Canis''. This often occurs in the wild, and in particular between domestic or feral dogs with wild native canids. Genetic considerations The wolf-like canids are a group of large carnivores that are genetically closely related because they all possess 78 chromosomes, arranged in 39 pairs and are karyologically indistinguishable from each other. The group includes the genera ''Canis'', ''Cuon'', ''Lupulella'' and ''Lycaon''. The members are the domestic dog ''(C. familiaris)'', gray wolf (''C. lupus''), dingo (''C. lupus dingo''), coyote (''C. latrans''), golden jackal (''C. aureus''), African wolf (''C. lupaster''), Ethiopian wolf (''C. simensis''), dhole (''Cuon alpinus''), black-backed jackal (''Lupulella mesomelas''), side-striped jackal (''L. adusta'') and African wild dog (''Lycaon pictus''). Newly proposed members include the red wolf (''Canis rufus''), and the eastern wolf (''Canis lycao ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feral Cat
A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens of generations and become an aggressive local apex predator in urban, savannah and bushland environments. Some feral cats may become more comfortable with people who regularly feed them, but even with long-term attempts at socialization, they usually remain aloof and are most active after dusk. Feral cats are devastating to wildlife, and conservation biologists consider them to be one of the worst invasive species on Earth. Attempts to control feral cat populations are widespread but generally of greatest impact within purpose-fenced reserves. Some animal rights groups advocate trap-neuter-return programs to prevent the feral cats from continuing to breed. Scientific evidence has demonstrated that TNR is not effective at controlling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Black Duck
The Pacific black duck (''Anas superciliosa''), commonly known as the PBD, is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east. It is usually called the gray duck in New Zealand, where it is also known by its Maori name, . Taxonomy The Pacific black duck was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's ''Systema Naturae''. He placed it with all the other ducks, geese and swans in the genus ''Anas'' and coined the binomial name ''Anas superciliosa''. Gmelin based his description on the "Supercilious duck" that had been described in 1785 by the English ornithologist John Latham in his ''A General Synopsis of Birds''. The naturalist Joseph Banks had provided Latham with a water-colour drawing of the duck by Georg Forster who had accompanied Jam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
