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Disruptive selection is a specific type of natural selection that actively selects against the intermediate in a population, favoring both extremes of the spectrum. Disruptive selection is inferred to oftentimes lead to sympatric speciation through a phyletic gradualism mode of evolution. Disruptive selection can be caused or influenced by ...
The uncommon disruptive selection also acts during transition periods when the current mode is sub-optimal, but alters the trait in more than one direction. In particular, if the trait is quantitative and univariate then both higher and lower trait levels are favoured. Disruptive selection can be a precursor to speciation. [57]
Natural selection has driven the ptarmigan to change from snow camouflage in winter to disruptive coloration suiting moorland in summer. Selective breeding transformed teosinte's small spikes (left) into modern maize (right). Darwin argued that evolution worked in a similar way.
Background selection describes the loss of genetic diversity at a locus due to negative selection against deleterious alleles with which it is in linkage disequilibrium. [1] The name emphasizes the fact that the genetic background, or genomic environment, of a mutation has a significant impact on whether it will be preserved versus lost from a population.
Coincident disruptive coloration is seen in other amphibians including the common frog, Rana temporaria, in which the dark and light bands that cross the body and hind legs coincide in the resting position, joining separate anatomical structures visually and breaking up and taking attention away from the body's actual outlines.
It is the selection against the heterozygote, causing disruptive selection [2] and divergent genotypes. Underdominance exists in situations where the heterozygotic genotype is inferior in fitness to either the dominant or recessive homozygotic genotype.
Disruptive selection is a specific type of natural selection that actively selects against the intermediate in a population, favoring both extremes of the spectrum. Disruptive selection is inferred to often times lead to sympatric speciation through a phyletic gradualism mode of evolution.
The maintenance of the ancestral flower color in the allopatric population is favored weakly by selection, where the derived color in the sympatric population is being driven by strong selection. [56] Similarly, in P. pilosa and P. glaberrima, character displacement of petal color has been driven by selection, aided by pollen discrimination. [57]