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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.
The first is directional selection, which is a shift in the average value of a trait over time—for example, organisms slowly getting taller. [80] Secondly, disruptive selection is selection for extreme trait values and often results in two different values becoming most common, with selection against the average value. This would be when ...
Disruptive (or diversifying) selection is selection favouring extreme trait values over intermediate trait values. Disruptive selection may cause sympatric speciation through niche partitioning . Some forms of balancing selection do not result in fixation, but maintain an allele at intermediate frequencies in a population.
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 ...
Variation over time, unlike variation over space, is not in itself enough to maintain multiple types, because in general the type with the highest geometric mean fitness will take over, but there are a number of mechanisms that make stable coexistence possible. [10]
Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes through time, often leading to reproductive isolation and continued mutation even after the populations have become reproductively isolated for some period of time, as there is not any genetic exchange anymore. [1]
In population genetics, directional selection is a type of natural selection in which one extreme phenotype is favored over both the other extreme and moderate phenotypes. This genetic selection causes the allele frequency to shift toward the chosen extreme over time as allele ratios change from generation to generation.
In a population, heritable traits that increase an organism's ability to survive and reproduce tend to increase in frequency over generations through a process known as natural selection. [4] The selection gradient shows how much an organism's relative fitness (ω) changes in response to a given increase or decrease in the value of a trait. It ...