Disruptive Selection
Disruptive selection - Wikipedia, the free encyclopedia
When disruptive selection operates, individuals at the extremes contribute more ... Disruptive selection is of particular significance in the history of ...
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Evolution
Disruptive Selection ... But evidently, disruptive selection is at work. ... The evolutionary significance of disruptive selection lies in the possibility ...
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natural selection: disruptive
Disruptive selection differs in that sudden changes in the environment creates a ... So disruptive selection occurs quickly, selecting for those extreme traits that ...
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Natural Selection and Variation
stabilizing, and disruptive forms of selection. We then ... illustrate disruptive selection and it does not much matter whether Figure 4.5a is called ...
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Parasite-mediated disruptive selection in a natural Daphnia population
Disruptive selection should not only increase a trait's variance but also can ... More specifically, disruptive selection can lead to a bimodal trait distribution ...
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natural selection: stabilizing
Stabilizing Selection. Directional Selection. Disruptive Selection. Speciation. Extinction ... Stabilizing selection favors the norm, the common, average ...
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Disruptive selection in a bimodal population of Darwin's ?nches
Supporting the theory, disruptive selection was strong. between the two beak size modes. ... process starts with divergent/disruptive selection causing ...
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Disruptive selection Summary and Analysis Summary
Disruptive selection summary with 5 pages of encyclopedia entries, essays, summaries, research information, and more. ... In disruptive selection, extremes of ...
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EvoTutor: Selection Modes
There are three general modes of selection: Directional Selection ... Disruptive Selection. Stabilizing Selection. Choose a selection mode to the right: ...
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Long-term Buildup of Reproductive Isolation Promoted by Disruptive ...
we thus conclude that disruptive selection per se is ... arises which is maintained by disruptive selection, ... tion under disruptive selection concentrate on the ...
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Disruptive selection is a descriptive term used to describe changes in population genetics that simultaneously favor individuals at both extremes of the distribution. When disruptive selection operates, individuals at the extremes contribute more offspring than those in the center, producing two peaks in the distribution of a particular Trait (biological).
Suppose there is a population of rabbits. The color of the rabbits is governed by two incompletely dominant traits: black fur represented by “B” and white fur represented by “b”. A rabbit with the genotype of “BB” would have a phenotype of black fur, a genotype of “Bb” would have gray fur (a display of both black and white) and a genotype of “bb” would have a phenotype of white fur.
If this population of rabbits were put into an area that had very dark black rocks as well as very white colored stone, the rabbits with black fur would be able to hide from predators amongst the black rocks and the white furred rabbits would be able to hide in the white rocks, but the gray furred rabbits would stand out in both of the habitats and thus would not survive.Disruptive Selection is believed to be the driving force behind sympatric speciation.
Disruptive selection is of particular significance in the history of evolutionary study, as it is involved in one of evolution's "cardinal cases", namely the Darwin's finches in the Galápagos.
He observed that the species of finches were similar enough to ostensibly have been descended from a single species. However, they exhibited disruptive variation in beak size. This variation appeared to be adaptively related to the seed size available on the respective islands (big beaks for big seeds, small beaks for small seeds). Medium beaks had difficulty retrieving small seeds and were also not tough enough for the bigger seeds, and were hence maladaptive.
While it is true that disruptive selection can lead to speciation, this is not as quick or straightforward of a process as other types of speciation or evolutionary change. This is largely because the results of disruptive selection are less stable than the results of directional selection (directional selection favours individuals at only one end of the spectrum).
For example, let us take the mathematically straightforward yet biologically improbable case of the rabbits: Suppose directional selection were taking place. The field only has dark rocks in it, so the darker the rabbit, the better. Eventually there will be a lot of black rabbits in the population (hence lots of B alleles) and a lesser amount of gray rabbits (who contribute 50% B chromosomes and 50% b chromosomes to the population). There will be few white rabbits (not very many contributors of b chromosomes to the population). This could eventually lead to a situation in which b chromosomes die out, making black the only possible colour for all subsequent rabbits. The reason for this is that there is nothing "boosting" the level of b chromosomes in the population. They can only go down, and eventually die out.
Consider now the case of disruptive selection. The result is equal numbers of black and white rabbits, and hence equal numbers of B and b chromosomes, still floating around in that population. Every time a white rabbit mates with a black one, a gray one results. So, in order for the results to "click", there needs to be a force causing white rabbits to choose other white rabbits, and black rabbits to choose other black ones. In the case of the finches, this "force" was geographic/niche isolation.
See also
Disruptive selection - Wikipedia, the free encyclopedia
Disruptive selection, also called diversifying selection, is a descriptive term used to describe changes in population genetics that simultaneously favor individuals at both ...
disruptive element films | homepage
video, sounds, blogs from disruptive element films ... July 7, 2008 FIRST - Offical Selection Edinburgh International Film Festival
Evolution - A-Z - Disruptive selection
Natural selection can sometimes favor extremes over the intermediate types. This is called disruptive selection. In nature, sexual dimorphism is probably a common example; but here ...
Disruptive selection definition of Disruptive selection in the Free ...
selection. In Darwinism Darwinism, concept of evolution developed in the mid-19th cent. by Charles Robert Darwin . Darwin's meticulously documented observations led him to question ...
disruptive technology definition of disruptive technology in the Free ...
A new technology that has a serious impact on the status quo and changes the way ... Disruptive selection Disruptive selection Disruptive selection Disruptive selection
BioMed Central | Full text | Analysis of disruptive selection in ...
Émile Ajar. Laboratoire Génétique et Environnement, Institut des Sciences de l'Évolution, CC065, USTL, Place E. Bataillon, 34095 Montpellier Cedex 05, France
Disruptive selection - definition of Disruptive selection by the Free ...
a. The act or an instance of selecting or the fact of having been selected. b. One that is selected.
EvoTutor: Selection Modes
Directional Selection. X Directional O Stabilizing O Disruptive. Stabilizing Selection. O Directional X Stabilizing O Disruptive. Disruptive Selection. O Directional
Disruptive selection - Psychology Wiki
Disruptive selection is a type of natural selection that simultaneously favors individuals at both extremes of the distribution. When disruptive selection operates, individuals ...
23:Disruptive (=diversifying) selection and speciation
23:Disruptive (=diversifying) selection and speciation. This could cause speciation if there is a link between the trait undergoing disruptive selection and assortative mating