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The neutral theory of molecular evolution, proposed by Motoo Kimura in 1968, holds that at the molecular level most evolutionary changes and most of the variation within and between species is not caused by natural selection but by genetic drift of mutant alleles that are neutral.
A 2019 review by Svensson and David Berger concluded that "we find little support for mutation bias as an independent force in adaptive evolution, although it can interact with selection under conditions of small population size and when standing genetic variation is limited, entirely consistent with standard evolutionary theory."
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 ...
The mechanisms of evolution focus mainly on mutation, genetic drift, gene flow, non-random mating, and natural selection. Mutation: Mutation [12] is a change in the DNA sequence inside a gene or a chromosome of an organism. Most mutations are deleterious, or neutral; i.e. they can neither harm nor benefit, but can also be beneficial sometimes.
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
The neutral theory of molecular evolution holds that most evolutionary changes occur at the molecular level, and most of the variation within and between species are due to random genetic drift of mutant alleles that are selectively neutral.
Example: We would like to model the substitution process in DNA sequences (i.e. Jukes–Cantor, Kimura, etc.) in a continuous-time fashion. The corresponding transition matrices will look like: The corresponding transition matrices will look like:
selection – selective breeding – selfish DNA – The Selfish Gene – sexual selection – signalling theory – sociobiology – social effects of evolutionary theory – species – speciation – species flock – sperm competition – stabilizing selection – strain (biology) – subspecies – survival of the fittest – symbiogenesis ...