Genetic response to pollution in sticklebacks; natural selection

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This fact increases the trait frequency within the population and alleles and genes that help to inform it. Stabilizing selection is the exact opposite of disruptive selection, as it favors the intermediate form of a trait against the extreme forms. It causes a reduction in the variation observed in the expression of that trait and allows the propagation of the intermediate, most adapted trait in the population. Stabilizing selection results in a decrease of a population ‘s genetic variance when natural selection favors an average phenotype and selects against extreme variations.

Stabilizing selection

Translated by Isadore Dordick. Edited by Theodosius Dobzhansky. Pp. xiv + 327. SEVERAL workers1–3 have recently pointed out the importance of the stabilizing type of natural selection, in which the intermediate phenotype has an adaptive The multivariate trait combinations experiencing the strongest stabilizing selection harbored very little genetic variation while combinations under weak selection We investigate maintenance of quantitative genetic variation at mutation- selection balance for multiple traits. The intrinsic strength of real stabilizing selection on Stabilizing selection is the opposite of disruptive selection. Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants. Stabilizing phenotypic selection, sexual selection.

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Stabilizing selection is a descriptive term for what happens to an individual trait when the extremes of the trait are selected against. 2017-09-04 Stabilizing selection is thought to be common in wild populations and act as one of the main evolutionary mechanisms, which constrain phenotypic variation. When multiple traits interact to create a combined phenotype, correlational selection may be an important process driving adaptive evolution. stabilizing selection (normalizing selection) Natural selection that acts to maintain the constancy of a species over successive generations. It involves selection against the extremes of the range of phenotypes for a particular characteristic. 1 CHAPTER 5 -- EVOLVABILITY, STABILIZING SELECTION, AND THE PROBLEM OF STASIS BY THOMAS F. HANSEN & DAVID HOULE "Organisms.. have not done nearly as much evolving as we should reasonably expect" Williams (1992, p 128).

Peccaries are eating those plants with low-spine-number causing their alleles to vanish from the gene pool and enriching the remaining gene pool in those alleles that create cacti with high-spine-numbers. 1996-12-20 · Stabilizing selection on a deme within one local community does not necessarily translate to similar stabilizing selection pressures across all demes of the species inhabiting different environments and communities, though it is theoretically possible (see Fig. lb).
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Purifying / stabilizing selection is not the sole cause of stasis.

Digest: Stabilizing selection on an animal weapon in a wild population. av E Lind · 2013 · Citerat av 1 — Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).
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Directional Selection When the environment changes, populations will often undergo directional selection, which selects for phenotypes at one end of the spectrum of existing variation. 2020-08-11 Get an answer for 'Briefly explain the difference between stabilizing selection, directional selection, and disruptive selection.' and find homework help for other Science questions at eNotes http://braingenie.com/ 2020-09-03 Stabilizing Selection Definition. Stabilizing selection is any selective force or forces which push a population toward the average, or median trait.

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There has been a renewed interest in investigating the role of stabilizing selection acting on genome-wide traits such as codon usage bias. Codon bias, when Stabilizing selection on the population was infrequently detected in an. "empirical " sampling protocol, because (1) trait variation was low relative to the fitness stabilizing selection the tendency of natural selection to function so as to maintain the existing mean of a population characteristic (e.g., mean height, mean neck The Theory of Stabilizing Selection. JAMA. 1950;142(12):949. doi:10.1001/jama. 1950.02910300087029.

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The main novel conclusion is that the scaled measure of the intensity of selection for individual sites under stabilizing selection (defined here as γ = 4 Nes) is approximately independent of Ne over a wide range of parameters, provided that there is sufficient mutational bias to perturb the population mean from the optimal value by a small amount, thereby creating an overall pressure of selection in the opposite direction to the effect of mutational bias. http://braingenie.com/ Balancing selection refers to a number of selective processes by which multiple alleles (different versions of a gene) are actively maintained in the gene pool of a population at frequencies larger than expected from genetic drift alone. stabilizing selection is not the norm. There appears to be fairly general acceptance of the idea that stabilizing selection is the cause of stasis. Even Gould, who may have been the most prominent champion of constraint hypotheses, recently acknowledged stabilizing selection based on niche tracking as a likely Stabilizing selection is thought to be common in wild populations and act as one of the main evolutionary mechanisms, which constrain phenotypic variation.

6, 2020. Digest: Stabilizing selection on an animal weapon in a wild population. av E Lind · 2013 · Citerat av 1 — Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).