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Fisher's Principle
Fisher's principle is an evolutionary model that explains why the sex ratio of most species that produce offspring through sexual reproduction is approximately 1:1 between males and females. A. W. F. Edwards has remarked that it is "probably the most celebrated argument in evolutionary biology". Fisher's principle was outlined by Ronald Fisher in his 1930 book ''The Genetical Theory of Natural Selection'' (but has been incorrectly attributed as original to Fisher). Fisher couched his argument in terms of parental expenditure, and predicted that parental expenditure on both sexes should be equal. Sex ratios that are 1:1 are hence known as "", and those that are ''not'' 1:1 are "" or "" and occur because they break the assumptions made in Fisher's model. Basic explanation W. D. Hamilton gave the following simple explanation in his 1967 paper on "Extraordinary sex ratios", given the condition that males and females cost equal amounts to produce: # Suppose male births are less commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation. The scientific theory of evolution by natural selection was conceived independently by two British naturalists, Charles Darwin and Alfred Russel Wallace, in the mid-19th century as an explanation for why organisms are adapted to their physical and biological environments. The theory was first set out in detail in Darwin's book ''On the Origin of Species''. Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) phenotypic variatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Descent Of Man
''The Descent of Man, and Selection in Relation to Sex'' is a book by English natural history, naturalist Charles Darwin, first published in 1871, which applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biological adaptation distinct from, yet interconnected with, natural selection. Darwin used the word "descent" to mean lineal descendant of ancestors. The book discusses many related issues, including evolutionary psychology, evolutionary ethics, evolutionary musicology, differences between human Race (classification of human beings), races, differences between sexes, the dominant role of women in mate choice, and the relevance of the evolutionary theory to society. Publication As Darwin wrote, he sent chapters to his daughter Darwin — Wedgwood family, Henrietta for editing to ensure that damaging inferences could not be drawn, and also took advice from his wife Emma Darwin, Emma. The zoological illustrator T. W. Wood, (who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene-centered View Of Evolution
The gene-centered view of evolution, gene's eye view, gene selection theory, or selfish gene theory holds that adaptive evolution occurs through the differential survival of competing genes, increasing the allele frequency of those alleles whose phenotypic trait effects successfully promote their own propagation. The proponents of this viewpoint argue that, since heritable information is passed from generation to generation almost exclusively by DNA, natural selection and evolution are best considered from the perspective of genes. Proponents of the gene-centered viewpoint argue that it permits understanding of diverse phenomena such as altruism and intragenomic conflict that are otherwise difficult to explain from an organism-centered viewpoint. Some proponents claim that the gene-centered view is the aspect of evolutionary theory that is the most empirically validated, has the greatest predictive power, and has the broadest applicability. The gene-centered view of evolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randolph M
Randolph may refer to: Places In the United States * Randolph, Alabama, an unincorporated community * Randolph, Arizona, a populated place * Randolph, California, a village merged into the city of Brea * Randolph, Illinois, an unincorporated community * Randolph, Indiana, an unincorporated community * Randolph, Iowa, a city * Randolph, Kansas, a city * Randolph, Maine, a town and a census-designated place * Randolph, Massachusetts, a city * Randolph, Minnesota, a city * Randolph, Mississippi, an unincorporated community * Randolph, Missouri, a city * Randolph, Nebraska, a city * Randolph, New Hampshire, a town * Randolph, New Jersey, a township * Randolph, New York, a town ** Randolph (CDP), New York * Randolph, Oregon, an unincorporated community * Randolph, Pennsylvania, an unincorporated community * Randolph, South Dakota, an unincorporated community * Randolph, Tennessee, an unincorporated community * Randolph, Texas, an unincorporated community * Randolph, Ut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Dawkins
Richard Dawkins (born 26 March 1941) is a British evolutionary biology, evolutionary biologist, zoologist, science communicator and author. He is an Oxford fellow, emeritus fellow of New College, Oxford, and was Simonyi Professor for the Public Understanding of Science, Professor for Public Understanding of Science at the University of Oxford from 1995 to 2008, and is on the advisory board of the University of Austin. His book ''The Selfish Gene'' (1976) popularised the gene-centred view of evolution and coined the word ''meme''. Dawkins has won several academic and writing awards. A vocal Atheism, atheist, Dawkins is known for his criticism of creationism and intelligent design. He wrote ''The Blind Watchmaker'' (1986), in which he argues against the watchmaker analogy, an argument for the existence of a creator deity based upon the Evolution of biological complexity, complexity of living organisms. Instead, he describes evolutionary processes as analogous to a ''blind'' watc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Christopher Williams
George Christopher Williams (May 12, 1926 – September 8, 2010) was an American evolutionary biologist. Williams was a professor of biology at the State University of New York at Stony Brook who was best known for his vigorous critique of group selection. The work of Williams in this area, along with W. D. Hamilton, John Maynard Smith, Richard Dawkins, and others led to the development of the gene-centered view of evolution in the 1960s. Academic work Williams' 1957 paper ''Pleiotropy, Natural Selection, and the Evolution of Senescence'' is one of the most influential in 20th century evolutionary biology, and contains at least 3 foundational ideas. The central hypothesis of antagonistic pleiotropy remains the prevailing evolutionary explanation of senescence. In this paper Williams was also the first to propose that senescence should be generally synchronized by natural selection. According to this original formulation ... if the adverse genic effects appeared earlier in one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology
Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere levels. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and is the study of abundance (ecology), abundance, biomass (ecology), biomass, and distribution of organisms in the context of the environment. It encompasses life processes, interactions, and adaptations; movement of materials and energy through living communities; ecological succession, successional development of ecosystems; cooperation, competition, and predation within and between species; and patterns of biodiversity and its effect on ecosystem processes. Ecology has practical applications in fields such as conservation biology, wetland management, natural resource m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Trivers
Robert Ludlow "Bob" Trivers (; born February 19, 1943) is an American evolutionary biologist and sociobiologist. Trivers proposed the theories of reciprocal altruism (1971), parental investment (1972), facultative sex ratio determination (1973), and parent–offspring conflict (1974). He has also contributed by explaining self-deception as an adaptive evolutionary strategy (first described in 1976) and discussing intragenomic conflict. Education Trivers studied evolutionary theory with Ernst Mayr and William Drury at Harvard from 1968 to 1972, when he earned his PhD in biology. At Harvard he published a series of some of the most influential and highly cited papers in evolutionary biology. His first major paper as a graduate student was "The evolution of reciprocal altruism", published in 1971. In this paper Trivers offers a solution to the longstanding problem of cooperation among unrelated individuals and by doing so overcame a crucial problem for how to police the sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parental Investment
Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure (e.g. time, energy, resources) that benefits offspring.Clutton-Brock, T.H. 1991. ''The Evolution of Parental Care''. Princeton, NJ: Princeton U. Press. pg. 9Trivers, R.L. (1972). Parental investment and sexual selection. In B. Campbell (Ed.), ''Sexual selection and the descent of man'', 1871-1971 (pp. 136–179). Chicago, IL: Aldine. . Parental investment may be performed by both males and females (called ''biparental care''), females alone (''exclusive maternal care'') or males alone (''exclusive paternal care''). Care can be provided at any stage of the offspring's life, from pre-natal (e.g. egg guarding and Egg incubation, incubation in birds, and placental nourishment in mammals) to post-natal (e.g. food provisioning and protection of offspring). Parental investment theory, a term coined by Robert Trivers in 1972, predicts that the sex that invests more in its offsprin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George R
George may refer to: Names * George (given name) * George (surname) People * George (singer), American-Canadian singer George Nozuka, known by the mononym George * George Papagheorghe, also known as Jorge / GEØRGE * George, stage name of Giorgio Moroder * George, son of Andrew I of Hungary Places South Africa * George, South Africa, a city ** George Airport United States * George, Iowa, a city * George, Missouri, a ghost town * George, Washington, a city * George County, Mississippi * George Air Force Base, a former U.S. Air Force base located in California Computing * George (algebraic compiler) also known as 'Laning and Zierler system', an algebraic compiler by Laning and Zierler in 1952 * GEORGE (computer), early computer built by Argonne National Laboratory in 1957 * GEORGE (operating system), a range of operating systems (George 1–4) for the ICT 1900 range of computers in the 1960s * GEORGE (programming language), an autocode system invented by Charles L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Maynard Smith
John Maynard Smith (6 January 1920 – 19 April 2004) was a British mathematical and theoretical biology, theoretical and mathematical evolutionary biologist and geneticist. Originally an aeronautical engineer during the Second World War, he took a second degree in genetics under the biologist J. B. S. Haldane. Maynard Smith was instrumental in the application of game theory to evolution with George R. Price, and theorised on other problems such as the evolution of sex and signalling theory. Biography Early years John Maynard Smith was born in London, the son of the surgeon Sidney Maynard Smith, but following his father's death in 1928, the family moved to Exmoor, where he became interested in natural history. Quite unhappy with the lack of formal science education at Eton College, Maynard Smith took it upon himself to develop an interest in Darwinism, Darwinian evolutionary theory and mathematics, after having read the work of old Etonian J. B. S. Haldane, whose books were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unbeatable Strategy
In biology, the idea of an unbeatable strategy was proposed by W.D. Hamilton in his 1967 paper on sex ratios in ''Science''. In this paper Hamilton discusses sex ratios as strategies in a game, and cites Verner as using this language in his 1965 paper which "claims to show that, given factors causing fluctuations of the population's primary sex ratio, a 1:1 sex-ratio production proves the best overall genotypic strategy". : "In the way in which the success of a chosen sex ratio depends on choices made by the co-parasitizing females, this problem resembles certain problems discussed in the "theory of games." In the foregoing analysis a game-like element, of a kind, was present and made necessary the use of the word ''unbeatable'' to describe the ratio finally established. This word was applied in just the same sense in which it could be applied to the "minimax" strategy of a zero-sum two-person game. Such a strategy should not, without qualification, be called optimum because it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
