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Fixed Allele
A fixed allele is an allele that is the only variant that exists for that gene in all the population. A fixed allele is homozygous for all members of the population. The term ''allele'' normally refers to one variant gene out of several possible for a particular locus in the DNA. When all but one allele go extinct and only one remains, that allele is said to be fixed. There are only two ways in which a fixed allele can become un-fixed. This can happen through random mutations that lead to the development of a new allele. Or this can happen through immigration. Fixed alleles were first defined by Motoo Kimura in 1962. He discussed how fixed alleles could arise within populations, and was the first to generalize the topic. He credits the works of Haldane in 1927 and Fisher in 1922 as being important in providing foundational information that allowed him to come to his conclusion. Kimura's later works were pivotal in the foundation of evolutionary and population genetics. Kimura is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Initial Pop
In a written or published work, an initial capital, also referred to as a drop capital or simply an initial cap, initial, initcapital, initcap or init or a drop cap or drop, is a letter at the beginning of a word, a chapter (books), chapter, or a paragraph that is larger than the rest of the text. The word is derived from the Latin ''initialis'', which means ''standing at the beginning''. An initial is often several lines in height and in older books or manuscripts are known as "inhabited" initials. Certain important initials, such as the Beatus initial or "B" of ''Beatus vir...'' at the opening of Psalm 1 at the start of a vulgate Latin. These specific initials in an illuminated manuscript were also called initiums. In the present, the word "initial" commonly refers to the first letter of any word or name, the latter normally Proper and common nouns#Capitalization, capitalized in English usage and is generally that of a first given name or a Middle initial , middle one or one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Founder's Effect
In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall Wright. As a result of the loss of genetic variation, the new population may be distinctively different, both genotype, genotypically and phenotype, phenotypically, from the parent population from which it is derived. In extreme cases, the founder effect is thought to lead to the speciation and subsequent evolution of new species. In the figure shown, the original population has nearly equal numbers of blue and red individuals. The three smaller founder populations show that one or the other color may predominate (founder effect), due to random sampling of the original population. A population bottleneck may also cause a founder effect, though it is not strictly a new population. The foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Eagle
The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird of prey, birds of prey in the Northern Hemisphere. These birds are dark brown, with lighter golden-brown plumage on their napes. Immature eagles of this species typically have white on the tail and often have white markings on the wings. Golden eagles use their agility and speed combined with powerful feet and large, sharp talons to hunt a variety of prey, mainly hares, rabbits, and marmots and other ground squirrels. Golden eagles maintain home ranges or territories that may be as large as . They build large bird nest, nests in cliffs and other high places to which they may return for several breeding years. Most breeding activities take place in the spring; they are monogamous and may remain together for several years or possibly for life. Fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canine Distemper
Canine distemper virus (CDV) (sometimes termed footpad disease) is a viral disease that affects a wide variety of mammal families, including domestic and wild species of dogs, coyotes, foxes, pandas, wolves, ferrets, skunks, raccoons, and felines, as well as pinnipeds, some primates, and a variety of other species. CDV does not affect humans. In canines CDV affects several body systems, including the gastrointestinal and respiratory tracts and the spinal cord and brain. Common symptoms include high fever, eye inflammation and eye/nose discharge, labored breathing and coughing, vomiting and diarrhea, loss of appetite and lethargy, and hardening of nose and footpads. The viral infection can be accompanied by secondary bacterial infections and can present eventual serious neurological symptoms. Canine distemper is caused by a single-stranded RNA virus of the family ''Paramyxoviridae'' (the same family of the viruses that causes measles, mumps, and bronchiolitis in humans). The d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Island Fox
The island fox (''Urocyon littoralis'') is a small fox that is endemic to six of the eight Channel Islands of California. There are six subspecies, each unique to the island it lives on, reflecting its evolutionary history. They are generally docile, show little fear of humans, and are easily tamed. Island foxes played an important role in the spiritual lives of native Channel Islanders. They have been likely semi-domesticated as pets, used as pelts, or for other functions, like pest control. Taxonomy and evolution The island fox shares the genus ''Urocyon'' with the mainland gray fox (''U. cinereoargenteus''), the species from which it is descended. Its small size is a result of insular dwarfism, a form of allopatric speciation. Because the island fox is geographically isolated, it has not acquired immunity to parasites and diseases brought in from the mainland and is especially vulnerable to those that the domestic dog may carry. In addition, predation by the golden eagle ('' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alloenzyme
Alloenzymes (or also called allozymes) are variant forms of an enzyme which differ structurally but not functionally from other allozymes coded for by different alleles at the same locus. These are opposed to isozymes, which are enzymes that perform the same function, but which are coded by genes located at different loci. Alloenzymes are common biological enzymes that exhibit high levels of functional evolutionary conservation throughout specific phyla and kingdoms. They are used by phylogeneticists as molecular markers to gauge evolutionary histories and relationships between different species. This can be done because allozymes do not have the same structure. They can be separated by capillary electrophoresis. However, some species are monomorphic for many of their allozymes which would make it difficult for phylogeneticists to assess the evolutionary histories of these species. In these instances, phylogeneticists would have to use another method to determine the evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsatellite
A microsatellite is a tract of repetitive DNA in which certain DNA motifs (ranging in length from one to six or more base pairs) are repeated, typically 5–50 times. Microsatellites occur at thousands of locations within an organism's genome. They have a higher mutation rate than other areas of DNA leading to high genetic diversity. Microsatellites are often referred to as short tandem repeats (STRs) by forensic geneticists and in genetic genealogy, or as simple sequence repeats (SSRs) by plant geneticists. Microsatellites and their longer cousins, the minisatellites, together are classified as VNTR (variable number of tandem repeats) DNA. The name "satellite" DNA refers to the early observation that centrifugation of genomic DNA in a test tube separates a prominent layer of bulk DNA from accompanying "satellite" layers of repetitive DNA. They are widely used for DNA profiling in cancer diagnosis, in kinship analysis (especially paternity testing) and in forensic identific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Palaearctic
The Western Palaearctic or Western Palearctic is part of the Palaearctic realm, one of the eight biogeographic realms dividing the Earth's surface. Because of its size, the Palaearctic is often divided for convenience into two, with Europe, North Africa, northern and central parts of the Arabian Peninsula, and part of temperate Asia, roughly to the Ural Mountains forming the western zone, and the rest of temperate Asia becoming the Eastern Palaearctic. Its exact boundaries differ depending on the authority in question, but the '' Handbook of the Birds of Europe, the Middle East, and North Africa: The Birds of the Western Palearctic'' (''BWP'') definition is widely used, and is followed by the most popular Western Palearctic checklist, that of the Association of European Rarities Committees (AERC). The Western Palearctic realm includes mostly boreal and temperate climate ecoregions. The Palaearctic region has been recognised as a natural zoogeographic region since Sclater propose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo (butterfly)
The Apollo or mountain Apollo (''Parnassius apollo''), is a butterfly of the family Papilionidae. Etymology The species is named in the classical tradition for the deity Apollo. Subspecies Subspecies include: * ''Parnassius apollo apollo'' L. * ''Parnassius apollo alpherakyi'' Krulikowsky, 1906 * ''Parnassius apollo bartholomaeus'' Stichel, 1899 * ''Parnassius apollo democratus'' Kulikowsky, 1906 * ''Parnassius apollo filabricus'' Sagarra, 1933 * ''Parnassius apollo gadorensis'' Rougeot & Capdeville, 1969 ( Sierra de Gádor). Extinct. * ''Parnassius apollo geminus'' Schawerda, 1907 * ''Parnassius apollo graecus'' Ziegler, 1901 * ''Parnassius apollo hesebolus'' Nordmann, 1851 * ''Parnassius apollo hispanicus'' Oberthür, 1909 Central (Spain) * ''Parnassius apollo limicola'' Stichel, 1906 * ''Parnassius apollo merzbacheri'' Fruhstorfer, 1906 * ''Parnassius apollo nevadensis'' Oberthür, 1891 (Sierra Nevada) * ''Parnassius apollo provincialis'' Kheil, 1905 * ''Parnassius apollo p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Nucleotide Polymorphism
In genetics, a single-nucleotide polymorphism (SNP ; plural SNPs ) is a germline substitution of a single nucleotide at a specific position in the genome. Although certain definitions require the substitution to be present in a sufficiently large fraction of the population (e.g. 1% or more), many publications do not apply such a frequency threshold. For example, at a specific base position in the human genome, the G nucleotide may appear in most individuals, but in a minority of individuals, the position is occupied by an A. This means that there is a SNP at this specific position, and the two possible nucleotide variations – G or A – are said to be the alleles for this specific position. SNPs pinpoint differences in our susceptibility to a wide range of diseases, for example age-related macular degeneration (a common SNP in the CFH gene is associated with increased risk of the disease) or nonalcoholic fatty liver disease (a SNP in the PNPLA3 gene is associated with incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Buffalo
The water buffalo (''Bubalus bubalis''), also called the domestic water buffalo or Asian water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also found in Europe, Australia, North America, South America and some African countries. Two extant types of water buffalo are recognized, based on morphological and behavioural criteria: the river buffalo of the Indian subcontinent and further west to the Balkans, Egypt and Italy and the swamp buffalo, found from Assam in the west through Southeast Asia to the Yangtze valley of China in the east. The wild water buffalo (''Bubalus arnee'') most likely represents the ancestor of the domestic water buffalo. Results of a phylogenetic study indicate that the river-type water buffalo probably originated in western India and was domesticated about 6,300 years ago, whereas the swamp-type originated independently from Mainland Southeast Asia and was domesticated about 3,000 to 7,000 years ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inbreeding
Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that may arise from expression of deleterious or recessive traits resulting from incestuous sexual relationships and consanguinity. Animals avoid incest only rarely. Inbreeding results in homozygosity, which can increase the chances of offspring being affected by recessive traits. In extreme cases, this usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is colloquially referred to as ''inbred''. The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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