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Neutral mutation has become a part of the neutral theory of molecular evolution, proposed in the 1960s. This theory suggests that neutral mutations are responsible for a large portion of DNA sequence changes in a species. For example, bovine and human insulin, while differing in amino acid sequence are still able to perform the same function ...
Nearly neutral mutations are those that carry selection coefficients less than the inverse of twice the effective population size. [30] The population dynamics of nearly neutral mutations are only slightly different from those of neutral mutations unless the absolute magnitude of the selection coefficient is greater than 1/N, where N is the ...
Neutral Evolution Theory, first proposed by Kimura in a 1968 paper, and later fully defined and published in 1983, is the basis for many statistical tests that detect selection at the molecular level. Kimura noted that there was much too high of a rate of mutation within the genome (i.e. high polymorphism) to be strictly under directional ...
Silent mutations, also called synonymous or samesense mutations, are mutations in DNA that do not have an observable effect on the organism's phenotype. The phrase silent mutation is often used interchangeably with the phrase synonymous mutation ; however, synonymous mutations are not always silent, nor vice versa.
A beneficial, or advantageous mutation increases the fitness of the organism. Examples are mutations that lead to antibiotic resistance in bacteria (which are beneficial for bacteria but usually not for humans). A neutral mutation has no harmful or beneficial effect on the organism.
Not all missense mutations lead to appreciable protein changes. An amino acid may be replaced by an amino acid of very similar chemical properties, in which case, the protein may still function normally; this is termed a neutral, "quiet", "silent" or conservative mutation.
A randomly evolving DNA sequence contains mutations with no effect on the fitness and survival of an organism. The randomly evolving mutations are called "neutral", while mutations under selection are "non-neutral". For example, a mutation that causes prenatal death or severe disease would be expected to be under selection.
A hitchhiker mutation (or passenger mutation in cancer biology) may itself be neutral, advantageous, or deleterious. [ 7 ] Recombination can interrupt the process of genetic hitchhiking, ending it before the hitchhiking neutral or deleterious allele becomes fixed or goes extinct. [ 6 ]