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Price Equation
In the theory of evolution and natural selection, the Price equation (also known as Price's equation or Price's theorem) describes how a trait or allele changes in frequency over time. The equation uses a covariance between a trait and fitness, to give a mathematical description of evolution and natural selection. It provides a way to understand the effects that gene transmission and natural selection have on the frequency of alleles within each new generation of a population. The Price equation was derived by George R. Price, working in London to re-derive W.D. Hamilton's work on kin selection. Price equation examples, Examples of the Price equation have been constructed for various evolutionary cases. The Price equation also has applications in economics. It is important to note that the Price equation is not a physical or biological law. It is not a concise or general expression of experimentally validated results. It is rather a purely mathematical relationship between variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Price Equation Examples
In the theory of evolution and natural selection, the Price equation expresses certain relationships between a number of statistical measures on parent and child populations. Without training in the understanding of these measures, the meaning of Price equation is rather opaque. For the less experienced person, simple and particular examples are vital to gaining an intuitive understanding of these statistical measures as they apply to populations, and the relationship between them as expressed in the Price equation. Evolution of sight As an example of the simple Price equation, consider a model for the evolution of sight. Suppose ''z''''i'' is a real number measuring the visual acuity of an organism. An organism with a higher ''z''''i'' will have better sight than one with a lower value of ''z''''i''. Let us say that the fitness of such an organism is ''W''''i''=''z''''i'' which means the more sighted it is, the fitter it is, that is, the more children it will produce. Beginnin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fisher's Fundamental Theorem Of Natural Selection
Fisher's fundamental theorem of natural selection is an idea about genetic variance in population genetics developed by the statistician and evolutionary biologist Ronald Fisher. The proper way of applying the abstract mathematics of the theorem to actual biology has been a matter of some debate. It states: :"The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time." Or in more modern terminology: :"The rate of increase in the mean fitness of any organism, at any time, that is ascribable to natural selection acting through changes in gene frequencies, is exactly equal to its genetic variance in fitness at that time". History The theorem was first formulated in Fisher's 1930 book ''The Genetical Theory of Natural Selection''. Fisher likened it to the law of entropy in physics, stating that "It is not a little instructive that so similar a law should hold the supreme position among the biological sciences". The model of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The Royal Society B
''Proceedings of the Royal Society'' is the main research journal of the Royal Society. The journal began in 1831 and was split into two series in 1905: * Series A: for papers in physical sciences and mathematics. * Series B: for papers in life sciences. Many landmark scientific discoveries are published in the Proceedings, making it one of the most historically significant science journals. The journal contains several articles written by the most celebrated names in science, such as Paul Dirac, Werner Heisenberg, Ernest Rutherford, Erwin Schrödinger, William Lawrence Bragg, Lord Kelvin, J.J. Thomson, James Clerk Maxwell, Dorothy Hodgkin and Stephen Hawking. In 2004, the Royal Society began ''The Journal of the Royal Society Interface'' for papers at the interface of physical sciences and life sciences. History The journal began in 1831 as a compilation of abstracts of papers in the ''Philosophical Transactions of the Royal Society'', the older Royal Society publication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BioShock 2
''BioShock 2'' is a first-person shooter video game developed by 2K Marin and published by 2K Games. It was released worldwide for PlayStation 3, Windows, and Xbox 360 on February 9, 2010; Feral Interactive released an OS X version on March 30, 2012. The game takes place in the dystopian underwater city of Rapture, eight years after the events of ''BioShock''. In the single-player campaign, players control the armored protagonist Subject Delta as he fights through Splicers—the psychotic human population of the city—using weapons and an array of genetic modifications. The game includes a story-driven multiplayer mode that takes place before the events of ''BioShock'', during Rapture's civil war. After the success of ''BioShock,'' 2K Games formed a new studio, 2K Marin, to create the sequel. 2K Australia, Arkane Studios, and Digital Extremes provided additional support. The developers focused on improving gameplay elements from the first game, and return to the Rapture sett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WΔZ
''WΔZ'' (pronounced ''double-u delta zed'') is a 2007 British crime horror thriller film directed by Tom Shankland and starring Stellan Skarsgård, Melissa George, Selma Blair and Tom Hardy. The film was released in the United States with the title ''The Killing Gene''. Plot A pair of detectives attempt to solve a series of grisly murders in a dark rain soaked New York in which each victim has the Price equation (wΔz = Cov (w,z) = βwzVz) carved into their chests . Detective Eddie Argo (Skarsgard) and his new partner Helen Westcott (George) decipher the strange equation and realize each victim must make a heinous choice: kill your loved ones or be killed. Soon, it is clear the perpetrator has suffered a similar fate and is now coping by attempting to solve this philosophical quandary. Cast * Stellan Skarsgård as Eddie Argo * Melissa George as Helen Westcott * Selma Blair as Jean Lerner * Tom Hardy as Pierre Jackson * Ashley Walters as Daniel Leone * Paul Kaye as Gelb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Dynamics
Evolutionary dynamics is the study of the Mathematics, mathematical principles according to which biological organisms as well as cultural ideas evolve and Evolution, evolved. This is mostly achieved through the mathematical discipline of population genetics, along with evolutionary game theory. Most population genetics considers changes in the frequencies of alleles at a small number of gene locus (genetics), loci. When infinitesimal effects at a large number of gene loci are considered, one derives quantitative genetics. Traditional population genetic models deal with alleles and genotypes, and are frequently stochastic. In evolutionary game theory, developed first by John Maynard Smith, evolutionary biology concepts may take a deterministic mathematical form, with selection acting directly on inherited phenotypes. These same models can be applied to studying the evolution of human preferences and ideologies. Many variants on these models have been developed, which incorporate we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Mutability
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Ratios
The sex ratio (or gender ratio) is usually defined as the ratio of males to females in a population. As explained by Fisher's principle, for evolutionary reasons this is typically about 1:1 in species which reproduce sexually. Many species deviate from an even sex ratio, either periodically or permanently. Examples include parthenogenic species, periodically mating organisms such as aphids, some eusocial wasps, bees, ants, and termites. The human sex ratio is of particular interest to anthropologists and demographers. In human societies, sex ratios at birth may be considerably skewed by factors such as the age of mother at birth and by sex-selective abortion and infanticide. Exposure to pesticides and other environmental contaminants may be a significant contributing factor as well. As of 2014, the global sex ratio at birth is estimated at 107 boys to 100 girls (1,000 boys per 934 girls).. Types In most species, the sex ratio varies according to the age profile of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterozygote Advantage
A heterozygote advantage describes the case in which the heterozygous genotype has a higher relative fitness (biology), fitness than either the homozygous Dominance (genetics), dominant or homozygous recessive gene, recessive genotype. Loci exhibiting heterozygote advantage are a small minority of loci. The specific case of heterozygote advantage due to a single locus (genetics), locus is known as overdominance. Overdominance is a rare condition in genetics where the phenotype of the heterozygote lies outside of the phenotypical range of both homozygote parents, and heterozygous individuals have a higher fitness (biology), fitness than homozygous individuals. Polymorphism (biology), Polymorphism can be maintained by Natural selection, selection favoring the heterozygote, and this mechanism is used to explain the occurrence of some kinds of genetic variation, genetic variability. A common example is the case where the heterozygote conveys both advantages and disadvantages, while bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Sickle Cell Anemia
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Sight
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
