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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] |
Fixation Index
The fixation index (FST) is a measure of population differentiation due to genetic structure. It is frequently estimated from Polymorphism (biology), genetic polymorphism data, such as single-nucleotide polymorphisms (SNP) or Microsatellite (genetics), microsatellites. Developed as a special case of Sewall WWright's F-statistics, it is one of the most commonly used statistics in population genetics. Its values range from 0 to 1, with 0 being no differentiation and 1 being complete differentiation. Interpretation This comparison of genetic variability within and between populations is frequently used in applied population genetics. The values range from 0 to 1. A zero value implies complete panmixia; that is, that the two populations are interbreeding freely. A value of one implies that all genetic variation is explained by the population structure, and that the two populations do not share any genetic diversity. For idealized models such as Isolation_by_distance#Sewall_Wright-_Ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melrose, Massachusetts
Melrose is a city located in the Greater Boston metropolitan area in Middlesex County, Massachusetts, United States. Its population as of the 2020 census was 29,817. It is a suburb located approximately seven miles north of Boston. It is situated in the center of the triangle created by Interstates 93, 95 and U.S. Route 1. The land that comprises Melrose was first settled in 1628 and was once part of Charlestown and then Malden. It became the Town of Melrose in 1850 and then the City of Melrose in 1900. History Melrose was originally called "Ponde Fielde" for its abundance of ponds and streams or "Mystic Side" because of its location in a valley north of the Mystic River. The area was first explored by Richard and Ralph Sprague in 1628 and became part of Charlestown in 1633 along with a large area of land encompassing most of the surrounding communities. City of Melrose. Retrieved January 26, 2008. In 1649, the neighborhood of Charlestown known as Malden was incorpora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balzan Prize
The International Balzan Prize Foundation awards four annual monetary prizes to people or organizations who have made outstanding achievements in the fields of humanities, natural sciences, culture, as well as for endeavours for peace and the brotherhood of man. History The assets behind the foundation were established by the Italian Eugenio Balzan (1874–1953), a part-owner of who had invested his assets in Switzerland and in 1933 had left Italy in protest against fascism. He left a substantial inheritance to his daughter Angela Lina Balzan (1892–1956), who at the time was suffering an incurable disease. Before her death, she left instructions for the foundation and since then it has two headquarters, the Prize administered from Milan, the Fund from Zurich. The first award was in fact one million Swiss francs to the Nobel Foundation in 1961. After 1962, a gap of 16 years followed when prizes recommenced with an award of half a million Swiss francs to Mother Teresa. Award ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Hunt Morgan Medal
The Thomas Hunt Morgan Medal is awarded by the Genetics Society of America (GSA) for lifetime contributions to the field of genetics. The medal is named after Thomas Hunt Morgan, the 1933 Nobel Prize winner, who received this award for his work with Drosophila ''Drosophila'' (), from Ancient Greek δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or p ... and his "discoveries concerning the role played by the chromosome in heredity." Morgan recognized that Drosophila, which could be bred quickly and inexpensively, had large quantities of offspring and a short life cycle, would make an excellent organism for genetic studies. His studies of the white-eye mutation and discovery of sex-linked inheritance provided the first experimental evidence that chromosomes are the carriers of genetic information. Subsequent studies in his la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwin Medal
The Darwin Medal is one of the medals awarded by the Royal Society for "distinction in evolution, biological diversity and developmental, population and organismal biology". In 1885, International Darwin Memorial Fund was transferred to the Royal Society. The fund was devoted for promotion of biological research, and was used to establish the Darwin Medal. The medal was first awarded to Alfred Russel Wallace in 1890 for "his independent origination of the theory of the origin of species by natural selection." The medal commemorates the work of English biologist Charles Darwin (1809–1882). Darwin, most famous for his 1859 book ''On the Origin of Species,'' was a fellow of the Royal Society, and had received the Royal Medal in 1853 and the Copley Medal in 1864. The diameter of the Darwin Medal is inch (5.7 cm). It is made of silver. The obverse has Darwin's portrait, while the reverse has a wreath of plants with Darwin's name in Latin, "Carolus Darwin". It is surrounded by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Medal Of Science
The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral science, behavioral and social sciences, biology, chemistry, engineering, mathematics and physics. The twelve member presidential Committee on the National Medal of Science is responsible for selecting award recipients and is administered by the National Science Foundation (NSF). It is the highest science award in the United States. History The National Medal of Science was established on August 25, 1959, by an act of the Congress of the United States under . The medal was originally to honor scientists in the fields of the "physical, biological, mathematical, or engineering sciences". The Committee on the National Medal of Science was established on August 23, 1961, by Executive order (United States), executive order 10961 of President John F. Kennedy. O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weldon Memorial Prize
The Weldon Memorial Prize, also known as the Weldon Memorial Prize and Medal, is given yearly by the University of Oxford. The prize is to be awarded without regard to nationality or membership of any University to the person who, in the judgement of the electors, has, in the ten years next preceding the date of the award, published the most noteworthy contribution to the development of mathematical or statistical methods applied to problems in Biology. (Biology shall, for the purposes of this clause, be interpreted as including Zoology, Botany, Anthropology, Sociology, Psychology, and Medical Science.) It is named in honor of Walter Frank Raphael Weldon, former Linacre Professor of Zoology at the University. It was established through the efforts of Francis Galton and Karl Pearson. Although intended to be given yearly, it has in the past been given less often. Recipients * 1911 David Heron [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Giraud Elliot Medal
The Daniel Giraud Elliot Medal is awarded by the U.S. National Academy of Sciences "for meritorious work in zoology or paleontology study published in a three to five year period." Named after Daniel Giraud Elliot, it was first awarded in 1917. List of Daniel Giraud Elliot Medal winners SourceNational Academy of Sciences * Terrie M. Williams (2024) :For her seminal work on the ecological physiology of large mammals. * Günter P. Wagner (2018) :For his fundamental contributions to the integration of developmental and evolutionary biology, including his rich and penetrating book ''Homology, Genes and Evolutionary Innovation'', which will orient research in evolutionary developmental biology for decades to come. * Jonathan B. Losos (2012) :For his novel and penetrating studies of adaptive radiation in vertebrates, notably his comprehensive study of Anolis lizards in tropical America, as summarized in his recent book, ''Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threshold Model
In mathematical or statistical modeling a threshold model is any model where a threshold value, or set of threshold values, is used to distinguish ranges of values where the behaviour predicted by the model varies in some important way. A particularly important instance arises in toxicology, where the model for the effect of a drug may be that there is zero effect for a dose below a critical or threshold value, while an effect of some significance exists above that value.Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. Certain types of regression model may include threshold effects. Collective behavior Threshold models are often used to model the behavior of groups, ranging from social insects to animal herds to human society. Classic threshold models were introduced by Sakoda, in his 1949 dissertation and the Journal of Mathematical Sociology (JMS vol 1 #1, 1971). They were subsequently developed by Schelling, Axelrod, and Granovetter to model collectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shifting Balance Theory
The shifting balance theory is a theory of evolution proposed in 1932 by Sewall Wright, suggesting that adaptive evolution may proceed most quickly when a population divides into subpopulations with restricted gene flow. The name of the theory is borrowed from Wright's metaphor of fitness landscapes ( evolutionary landscapes), attempting to explain how a population may move across an adaptive valley to a higher adaptive peak. According to the theory, this movement occurs in three steps: #Genetic drift allows a locally adapted subpopulation to move across an adaptive valley to the base of a higher adaptive peak. #Natural selection will move the subpopulation up the higher peak. #This new superiorly adapted subpopulation may then expand its range and outcompete or interbreed with other subpopulations, causing the spread of new adaptations and movement of the global population toward the new fitness peak. Although shifting balance theory has been influential in evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Path Analysis (statistics)
In statistics, path analysis is used to describe the directed dependencies among a set of variables. This includes models equivalent to any form of multiple regression analysis, factor analysis, canonical correlation analysis, discriminant analysis, as well as more general families of models in the multivariate analysis of variance and covariance analyses (MANOVA, ANOVA, ANCOVA). In addition to being thought of as a form of multiple regression focusing on causality, path analysis can be viewed as a special case of structural equation modeling (SEM) – one in which only single indicators are employed for each of the variables in the causal model. That is, path analysis is SEM with a structural model, but no measurement model. Other terms used to refer to path analysis include causal modeling and analysis of covariance structures. Path analysis is considered by Judea Pearl to be a direct ancestor to the techniques of causal inference. History Path analysis was developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coefficient Of Relationship
The coefficient of relationship is a measure of the degree of consanguinity (or biological relationship) between two individuals. The term coefficient of relationship was defined by Sewall Wright in 1922, and was derived from his definition of the coefficient of inbreeding of 1921. The measure is most commonly used in genetics and genealogy. A coefficient of inbreeding can be calculated for an individual, and is typically one-half the coefficient of relationship between the parents. In general, the higher the level of inbreeding the closer the coefficient of relationship between the parents approaches a value of 1, expressed as a percentage, and approaches a value of 0 for individuals with arbitrarily remote common ancestors. Coefficient of relationship The coefficient of relationship r between two people B and C is obtained by a summation of coefficients calculated for every line by which they are connected to their identical ancestors point, common ancestors. Each such line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
