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Panmixia
Panmixia (or panmixis) means uniform random fertilization, which means individuals do not select a mate based on physical traits. A panmictic population is one where all potential parents may contribute equally to the gamete pool, and that these gametes are uniformly distributed within the gamete population (gamodeme). This assumes that there are no hybridising restrictions within the parental population: neither genetics, cytogenetics nor behavioural; and neither spatial nor temporal (see also Quantitative genetics for further discussion). True panmixia is rarely, if ever, observed in natural populations. It is a theoretical model used as a null hypothesis in population genetics. It serves as a point of comparison to understand how deviations from random mating affect allele and genotype frequencieTherefore, all gamete recombination (fertilization) is uniformly possible. Both the Wahlund effect and the Hardy Weinberg equilibrium assume that the overall population is panmictic. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantitative Genetics
Quantitative genetics is the study of quantitative traits, which are phenotypes that vary continuously—such as height or mass—as opposed to phenotypes and gene-products that are Categorical variable, discretely identifiable—such as eye-colour, or the presence of a particular biochemical. Both of these branches of genetics use the frequencies of different alleles of a gene in breeding populations (gamodemes), and combine them with concepts from simple Mendelian inheritance to analyze inheritance patterns across generations and descendant lines. While population genetics can focus on particular genes and their subsequent metabolic products, quantitative genetics focuses more on the outward phenotypes, and makes only summaries of the underlying genetics. Due to the continuous distribution of phenotypic values, quantitative genetics must employ many other statistical methods (such as the ''effect size'', the ''mean'' and the ''variance'') to link phenotypes (attributes) to gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatric Speciation
Sympatric speciation is the evolution of a new species from a surviving Common descent, ancestral species while both continue to inhabit the same geographic region. In evolutionary biology and biogeography, ''sympatric'' and ''sympatry'' are terms referring to organisms whose Range (biology), ranges overlap so that they occur together at least in some places. If these organisms are closely related (e.g. sister species), such a distribution may be the result of sympatric speciation. Etymologically, sympatry is derived . The term was coined by Edward Bagnall Poulton in 1904, who explains the derivation. Sympatric speciation is one of three traditional geographic modes of speciation.Futuyma, D. J. 2001. ''Evolution'' (2nd edition). Sinauer Associates, Inc. Allopatric speciation is the evolution of species caused by the geographic isolation of two or more populations of a species. In this case, divergence is facilitated by the absence of gene flow. Parapatric speciation is the evolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population
Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and plants, and has specific uses within such fields as ecology and genetics. Etymology The word ''population'' is derived from the Late Latin ''populatio'' (a people, a multitude), which itself is derived from the Latin word ''populus'' (a people). Use of the term Social sciences In sociology and population geography, population refers to a group of human beings with some predefined feature in common, such as location, Race (human categorization), race, ethnicity, nationality, or religion. Ecology In ecology, a population is a group of organisms of the same species which inhabit the same geographical area and are capable of Sexual reproduction, interbreeding. The area of a sexual population is the area where interbreeding is possi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Phenotypic trait, Trait inheritance and Molecular genetics, molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the Cell (bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sewall Wright
Sewall Green Wright ForMemRS HonFRSE (December 21, 1889March 3, 1988) was an American geneticist known for his influential work on evolutionary theory and also for his work on path analysis. He was a founder of population genetics alongside Ronald Fisher and J. B. S. Haldane, which was a major step in the development of the modern synthesis combining genetics with evolution. He discovered the inbreeding coefficient and methods of computing it in pedigree animals. He extended this work to populations, computing the amount of inbreeding between members of populations as a result of random genetic drift, and along with Fisher he pioneered methods for computing the distribution of gene frequencies among populations as a result of the interaction of natural selection, mutation, migration and genetic drift. Wright also made major contributions to mammalian and biochemical genetics. Biography Sewall Wright was born in Melrose, Massachusetts, to Philip Green Wright and Elizabe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Eel
The American eel (''Anguilla rostrata'') is a facultative catadromous eel found on the eastern coast of North America. Anguillidae, Freshwater eels are fish belonging to the Elopomorpha, elopomorph superorder, a group of Phylogenetics, phylogenetically ancient teleosts. The American eel has a slender, supple, snake-like body that is covered with a mucus layer, which makes the eel appear to be naked and slimy despite the presence of minute Fish scale, scales. A long dorsal fin runs from the middle of the back and is continuous with a similar ventral fin. Pelvic fins are absent, and relatively small pectoral fin, pectoral fins can be found near the midline, followed by the head and gill covers. Variations exist in coloration, from olive green, brown shading to greenish-yellow and light gray or white on the belly. Eels from clear water are often lighter than those from dark, Blackwater river, tannic acid streams. The eel lives in fresh water and estuaries and only leaves these habi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantala Flavescens
''Pantala flavescens'', the globe skimmer, globe wanderer or wandering glider, is a wide-ranging dragonfly of the family Libellulidae. This species and ''Pantala hymenaea'', the "spot-winged glider", are the only members of the genus ''Pantala''. It was first described by Johan Christian Fabricius in 1798. It is considered to be the most widespread dragonfly on the planet, with good population on every continent except Antarctica, although rare in Europe. Globe skimmers make an annual multigenerational journey of some 18,000 km (about 11,200 miles); to complete the migration, individual globe skimmers fly more than 6,000 km (3,730 miles)—one of the farthest known migrations of all insect species. Characteristics Structure of the adult The dragonfly is up to 4.5 cm long, reaching wingspans between 7.2 cm and 8.4 cm. The front side of the head is yellowish to reddish. The thorax is usually yellow to golden coloured with a dark and hairy line. There were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amegilla Dawsoni
''Amegilla dawsoni'', sometimes called the Dawson's burrowing bee, is a species of bee that nests by the thousands in arid claypans in Western Australia. It is a long tongued bee, of the tribe Anthophorini and genus ''Amegilla,'' the second largest genus in Anthophorini. The Dawson's burrowing bee is one of the largest Australian bee species, growing to be in length and in wingspan. With the exception of their faces, the bees are covered in brown fur, if male, or brown and white fur if female. They are similar in size and coloring to Australian carpenter bees. They are known solitary nesters. Though each female bee will build her own nest, they aggregate in large communities that give the appearance of colonies. Their nests are dug into the ground, with individual capsules created for each brood cell. Each female will only breed once in their breeding season. The males of the species are dimorphic, based on brood provisioning strategies during development. The larger mal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monostroma
''Monostroma'' is a genus of marine green algae (seaweed) in the family Monostromataceae. As the name suggests, algae of this genus are monostromatic (single cell layered). '' Monostroma kuroshiense'', an algae of this genus, is commercially cultivated in East Asia and South America for the edible product "hitoegusa-nori" or "hirohano-hitoegusa nori", popular sushi wraps. ''Monostroma'' oligosaccharides with degree of polymerization 6 prepared by agarase digestion from ''Monostroma nitidum'' polysaccharides have been shown to be an effective prophylactic agent during ''in vitro'' and ''in vivo'' tests against Japanese encephalitis viral infection. The sulfated oligosaccharides from ''Monostroma'' seem to be promising candidates for further development as antiviral agents. The genus ''Monostroma'' is the most widely cultivated genus among green seaweeds. Classification Species-level classification within this genus is quite problematic and no consensus exists among algal taxono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantala Flavescens-Kadavoor-2017-05-04-002
''Pantala'' is a genus of dragonfly in the family Libellulidae commonly called the rainpool gliders. They are found almost worldwide. Species of ''Pantala'' are medium-sized to large, dull orange-yellow dragonflies. Species The genus ''Pantala'' includes the following species: References External links * * {{Taxonbar, from=Q149707 Libellulidae Anisoptera genera Odonata of Africa Odonata of Asia Odonata of Australia Odonata of Oceania Taxa named by Hermann August Hagen Insects described in 1861 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
