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Haplotype Convergence
Haplotype convergence is the unrelated appearance of identical haplotypes in separate populations, through either convergent evolution or random chance. Description Haplotype convergence is rare, due to the sheer odds involved of two unrelated individuals independently evolving exactly the same genetic sequence in the site of interest. Thus, haplotypes are shared mainly between very closely related individuals, as the genetic information in two related individuals will be much more similar than between unrelated individuals. Substitution bias further increases the likelihood of haplotype convergence, as this increases the probability of mutations occurring at the same site. Sequences may also diverge from the same original sequence and then revert, converging in this manner. Convergence through convergent evolution in two unrelated groups is much less common, as derived traits may arise through dramatically different pathways. Erroneously determining two indiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplotype
A haplotype ( haploid genotype) is a group of alleles in an organism that are inherited together from a single parent. Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA organized in two sets of pairwise similar chromosomes. The offspring gets one chromosome in each pair from each parent. A set of pairs of chromosomes is called diploid and a set of only one half of each pair is called haploid. The haploid genotype (haplotype) is a genotype that considers the singular chromosomes rather than the pairs of chromosomes. It can be all the chromosomes from one of the parents or a minor part of a chromosome, for example a sequence of 9000 base pairs. However, there are other uses of this term. First, it is used to mean a collection of specific alleles (that is, specific DNA sequences) in a cluster of tightly linked genes on a chromosome that are likely to be inherited together—that is, they are likely to be co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas ''homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to paralle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin - Southern California Academy Of Sciences (2011) (19881439204)
Bulletin or The Bulletin may refer to: Periodicals (newspapers, magazines, journals) * Bulletin (online newspaper), a Swedish online newspaper * ''The Bulletin'' (Australian periodical), an Australian magazine (1880–2008) ** Bulletin Debate, a famous dispute from 1892 to 1893 between Henry Lawson and Banjo Paterson * ''The Bulletin'' (alternative weekly), an alternative weekly published in Montgomery County, Texas, U.S. * ''The Bulletin'' (Bend), a daily newspaper in Bend, Oregon, U.S. * ''The Bulletin'' (Belgian magazine), a weekly English-language magazine published in Brussels, Belgium * ''The Bulletin'' (Philadelphia newspaper), a newspaper in Philadelphia, Pennsylvania, U.S. (2004–2009) * ''The Bulletin'' (Norwich) * ''The Bulletin'' (Pittsburgh), a monthly community newspaper in Pittsburgh, Pennsylvania, U.S. * ''London Bulletin'', surrealist monthly magazine (1938–1940) * ''The Morning Bulletin'', a daily newspaper published in Rockhampton, Queensland, Austral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being deri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervariable Region
A hypervariable region (HVR) is a location within nuclear DNA or the D-loop of mitochondrial DNA in which base pairs of nucleotides repeat (in the case of nuclear DNA) or have substitutions (in the case of mitochondrial DNA). Changes or repeats in the hypervariable region are highly polymorphic. Mitochondrial There are two MITOCHONDRIAL hypervariable regions used in human mitochondrial genealogical DNA testing. HVR1 is considered a "low resolution" region and HVR2 is considered a "high resolution" region. Getting HVR1 and HVR2 DNA tests can help determine one's haplogroup. In the revised Cambridge Reference Sequence of the human mitogenome, the most variable sites of HVR1 are numbered 16024-16383 (this subsequence is called HVR-I), and the most variable sites of HVR2 are numbered 57-372 (''i.e.,'' HVR-II) and 438-574 (''i.e.,'' HVR-III).''PhyloTree mt''"Annotated mtDNA reference sequences: revised Cambridge Reference Sequence (rCRS)" Retrieved on 4 February 2016. In some bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-spined Stickleback
The three-spined stickleback (''Gasterosteus aculeatus'') is a fish native to most inland and coastal waters north of 30°N. It has long been a subject of scientific study for many reasons. It shows great morphological variation throughout its range, ideal for questions about evolution and population genetics. Many populations are anadromous (they live in seawater but breed in fresh or brackish water) and very tolerant of changes in salinity, a subject of interest to physiologists. It displays elaborate breeding behavior (defending a territory, building a nest, taking care of the eggs and fry) and it can be social (living in shoals outside the breeding season) making it a popular subject of inquiry in fish ethology and behavioral ecology. Its antipredator adaptations, host-parasite interactions, sensory physiology, reproductive physiology, and endocrinology have also been much studied. Facilitating these studies is the fact that the three-spined stickleback is easy to find in na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lucania Goodei
''Lucania goodei'', the bluefin killifish, is a small species of fish in the topminnow family Fundulidae. It is native to the southeastern United States, but has been introduced to California, Texas and North Carolina. Other common names for the fish include Florida blue dace.Halstead, Bruce. Tropical Fish (A Golden Guide). Golden Books. New York: 1989. Distribution The bluefin killifish is found throughout Florida, except for its panhandle, where it is not found west of the Choctawhatchee River. It is found in the Chipola River drainage of southeastern Alabama, and sporadically along the Atlantic coast up to central South Carolina. It has been introduced to Texas, North Carolina, and California. Description Normally, the bluefin killifish can grow up to , but the maximum length recorded is . The maximum recorded age of the bluefin killifish is 2 years. Ecology ''Lucania goodei'' lives in heavily vegetated ponds and streams with little to no current. It is often found in spring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthopagrus Butcheri
''Acanthopagrus butcheri'', the black bream but also commonly known as the southern black bream, southern bream and blue-nosed bream, is a species of marine and freshwater fish of the porgy family, Sparidae. It is a deep-bodied fish, occasionally confused with other similar species that occur within its range, but is generally distinguished from these species by a lack of yellow ventral and anal fins. Southern black bream are endemic to Australia, inhabiting the southern coast from Shark Bay in Western Australia to Ulladulla, New South Wales, as well as Tasmania. The species is primarily an inhabitant of estuaries and coastal lakes, rarely entering the ocean, as it cannot complete its life cycle in a fully marine environment. During the breeding season, the species is known to penetrate into the upper reaches of rivers to spawn, causing an influx of juveniles in the estuaries a few months later. Black bream are opportunistic predators, consuming a wide range of crustaceans, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life forms on Earth. Evolution is based on the theory that all species are related and they gradually change over time. In a population, the genetic variations affect the physical characteristics i.e. phenotypes of an organism. These changes in the phenotypes will be an advantage to some organisms, which will then be passed onto their offspring. Some examples of evolution in species over many generations are the Peppered Moth and Flightless birds. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology. The importance of studying Evolutionary biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
