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J. B. S. Haldane
John Burdon Sanderson Haldane (; 5 November 18921 December 1964), nicknamed "Jack" or "JBS", was a British-Indian scientist who worked in physiology, genetics, evolutionary biology, and mathematics. With innovative use of statistics in biology, he was one of the founders of neo-Darwinism. He served in the Great War, and obtained the rank of captain. Despite his lack of an academic degree in the field, he taught biology at the University of Cambridge, the Royal Institution, and University College London. Renouncing his British citizenship, he became an Indian citizen in 1961 and worked at the Indian Statistical Institute for the rest of his life. Haldane's article on abiogenesis in 1929 introduced the " primordial soup theory", which became the foundation for the concept of the chemical origin of life. He established human gene maps for haemophilia and colour blindness on the X chromosome, and codified Haldane's rule on sterility in the heterogametic sex of hybrids in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford
Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the University of Oxford, the oldest university in the English-speaking world; it has buildings in every style of English architecture since late Anglo-Saxon. Oxford's industries include motor manufacturing, education, publishing, information technology and science. History The history of Oxford in England dates back to its original settlement in the Saxon period. Originally of strategic significance due to its controlling location on the upper reaches of the River Thames at its junction with the River Cherwell, the town grew in national importance during the early Norman period, and in the late 12th century became home to the fledgling University of Oxford. The city was besieged during The Anarchy in 1142. The university rose to dom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Genetics
Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as Adaptation (biology), adaptation, speciation, and population stratification, population structure. Population genetics was a vital ingredient in the emergence of the Modern synthesis (20th century), modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and Ronald Fisher, who also laid the foundations for the related discipline of quantitative genetics. Traditionally a highly mathematical discipline, modern population genetics encompasses theoretical, laboratory, and field work. Population genetic models are used both for statistical inference from DNA sequence data and for proof/disproof of concept. What sets population genetics apart from newer, more phenotypic approaches to modelling evolution, such as evolutionary game theory and evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charlotte Haldane
Charlotte Haldane (; 27 April 1894 – 16 March 1969) was a British feminist writer.Elizabeth Russell, "The Loss of the Feminine Principle in Charlotte Haldane's ''Man's World'' and Katherine Burdekin's "Swastika Night" in Lucie Armitt, ''Where no man has gone before : women and science fiction''. London Routledge, 1991. . (pp. 15-28) Her second husband was the biologist J.B.S. Haldane. Biography Charlotte Franken was born in Sydenham, London. W. D. Rubinstein; Michael Jolles; Hilary L. Rubinstein, ''The Palgrave dictionary of Anglo-Jewish history''. Basingstoke: Palgrave Macmillan, 2011. (pp. 387–388) Her parents were Jewish immigrants, her father, Joseph, a German fur trader. In 1906 the family moved to Antwerp. She enrolled on a typing course in London. Charlotte later described herself as a "feminist and suffragette" from the age of sixteen. During the First World War her parents were interned but emigrated in 1915 to the United States. She married Jack Burghes in 191 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darwin–Wallace Medal
The Darwin–Wallace Medal is a medal awarded by the Linnean Society of London for "major advances in evolutionary biology". Historically, the medals have been awarded every 50 years, beginning in 1908. That year marked 50 years after the joint presentation by Charles Darwin and Alfred Russel Wallace of two scientific papers—''On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection''—to the Linnean Society of London on 1 July 1858. Fittingly, Wallace was one of the first recipients of the medal, in his case it was, exceptionally, in gold, rather than the silver version presented in the six other initial awards. However, in 2008 the Linnean Society announced that due to the continuing importance of evolutionary research, the medal will be awarded on an annual basis beginning in 2010. Awardees 1908 The first award was of a gold medal to Alfred Russel Wallace, and silver medals to six other distinguished ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selection Shadow
The selection shadow is a concept involved with the evolutionary theories of aging that states that selection pressures on an individual decrease as an individual ages and passes sexual maturity, resulting in a "shadow" of time where selective fitness is not considered. Over generations, this results in maladaptive mutations that accumulate later in life due to aging being non-adaptive toward reproductive fitness. The concept was first worked out by J. B. S. Haldane and Peter Medawar in the 1940s, with Medawar creating the first graphical model. Model The model developed by Medawar states that due to the dangerous conditions and pressures from the environment, including predators and diseases, most individuals in the wild die not long after sexual maturity. Therefore, there is a low probability for individuals to survive to an advanced age and suffer the effects related to aging. In conjunction with this, the effects of natural selection decrease as age increases, so that later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kin Selection
Kin selection is the evolutionary strategy that favours the reproductive success of an organism's relatives, even when at a cost to the organism's own survival and reproduction. Kin altruism can look like altruistic behaviour whose evolution is driven by kin selection. Kin selection is an instance of inclusive fitness, which combines the number of offspring produced with the number an individual can ensure the production of by supporting others, such as siblings. Charles Darwin discussed the concept of kin selection in his 1859 book, ''On the Origin of Species'', where he reflected on the puzzle of sterile social insects, such as honey bees, which leave reproduction to their mothers, arguing that a selection benefit to related organisms (the same "stock") would allow the evolution of a trait that confers the benefit but destroys an individual at the same time. R.A. Fisher in 1930 and J.B.S. Haldane in 1932 set out the mathematics of kin selection, with Haldane famously jokin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is the quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Darw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterotrophic Theory
Primordial soup, also known as, primordial goo, primordial ooze, prebiotic soup and prebiotic broth, is the hypothetical set of conditions present on the Earth around 3.7 to 4.0 billion years ago. It is an aspect of the heterotrophic theory (also known as the Oparin–Haldane hypothesis) concerning the origin of life, first proposed by Alexander Oparin in 1924, and J. B. S. Haldane in 1929. As formulated by Oparin, in the primitive Earth's surface layers, carbon, hydrogen, water vapour, and ammonia reacted to form the first organic compounds. The concept of a primordial soup gained credence in 1953 when the "Miller–Urey experiment" used a highly reduced mixture of gases—methane, ammonia and hydrogen—to form basic organic monomers, such as amino acids. Historical background The notion that living beings originated from inanimate materials comes from the Ancient Greeks—the theory known as spontaneous generation. Aristotle in the 4th century BCE gave a proper explanation, wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primordial Soup
Primordial soup, also known as, primordial goo, primordial ooze, prebiotic soup and prebiotic broth, is the hypothetical set of conditions present on the Earth around 3.7 to 4.0 billion years ago. It is an aspect of the heterotrophic theory (also known as the Oparin–Haldane hypothesis) concerning the origin of life, first proposed by Alexander Oparin in 1924, and J. B. S. Haldane in 1929. As formulated by Oparin, in the primitive Earth's surface layers, carbon, hydrogen, water vapour, and ammonia reacted to form the first organic compounds. The concept of a primordial soup gained credence in 1953 when the "Miller–Urey experiment" used a highly reduced mixture of gases—methane, ammonia and hydrogen—to form basic organic monomers, such as amino acids. Historical background The notion that living beings originated from inanimate materials comes from the Ancient Greeks—the theory known as spontaneous generation. Aristotle in the 4th century BCE gave a proper explanation, wri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haldane's Dilemma
Haldane's dilemma, also known as "the waiting time problem", is a limit on the speed of beneficial evolution, calculated by J. B. S. Haldane in 1957. Before the invention of DNA sequencing technologies, it was not known how much polymorphism DNA harbored, although alloenzymes (variant forms of an enzyme which differ structurally but not functionally from other alloenzymes coded for by different alleles at the same locus) were beginning to make it clear that substantial polymorphism existed. This was puzzling because the amount of polymorphism known to exist seemed to exceed the theoretical limits that Haldane calculated, that is, the limits imposed if polymorphisms present in the population generally influence an organism's fitness. Motoo Kimura's landmark paper on neutral theory in 1968 built on Haldane's work to suggest that most molecular evolution is neutral, resolving the dilemma. Although neutral evolution remains the consensus theory among modern biologists, and thus Ki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haldane's Principle
John Burdon Sanderson Haldane (; 5 November 18921 December 1964), nicknamed "Jack" or "JBS", was a British-Indian scientist who worked in physiology, genetics, evolutionary biology, and mathematics. With innovative use of statistics in biology, he was one of the founders of neo-Darwinism. He served in the Great War, and obtained the rank of captain. Despite his lack of an academic degree in the field, he taught biology at the University of Cambridge, the Royal Institution, and University College London. Renouncing his British citizenship, he became an Indian citizen in 1961 and worked at the Indian Statistical Institute for the rest of his life. Haldane's article on abiogenesis in 1929 introduced the "primordial soup theory", which became the foundation for the concept of the chemical origin of life. He established human gene maps for haemophilia and colour blindness on the X chromosome, and codified Haldane's rule on sterility in the heterogametic sex of hybrids in sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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