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In evolutionary biology, disruptive selection, also called diversifying selection, describes changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups.
disruptive selection. Also diversifying selection. A mode of natural selection in which the extreme values of a trait or phenotype within a breeding population are favored over intermediate values, causing allele frequencies to shift over time away from the intermediate. This causes the variance in the trait to increase and results in the ...
In general, two types of experiments have been conducted: using artificial selection to mimic natural selection that eliminates the hybrids (often called "destroy-the-hybrids"), and using disruptive selection to select for a trait (regardless of its function in sexual reproduction).
Genetic divergence will always accompany reproductive isolation, either due to novel adaptations via selection and/or due to genetic drift, and is the principal mechanism underlying speciation. On a molecular genetics level, genetic divergence is due to changes in a small number of genes in a species, resulting in speciation . [ 2 ]
The so-called 'dosage' of a gene refers to the amount of mRNA transcripts and subsequently translated protein molecules produced from a gene per time and per cell. If the amount of gene product is below its optimal level, there are two kinds of mutations that can increase dosage: increases in gene expression by promoter mutations and increases ...
Stabilizing selection conserves functional genetic features, such as protein-coding genes or regulatory sequences, over time by selective pressure against deleterious variants. [105] Disruptive (or diversifying) selection is selection favoring extreme trait values over intermediate trait values.
The Black Queen hypothesis is a theory of reductive evolution that suggests natural selection can drive organisms to reduce their genome size. [37] In other words, a gene that confers a vital biological function can become dispensable for an individual organism if its community members express that gene in a "leaky" fashion.
It is sometimes called the invasion fitness of mutants. To make use of these ideas, a mathematical model must explicitly incorporate the traits undergoing evolutionary change. The model should describe both the environment and the population dynamics given the environment, even if the variable part of the environment consists only of the ...