Neutral Mutation

In genetics, a neutral mutation is a mutation that has no effect on fitness. In other words, it is neutral with respect to natural selection.

For example, some mutations in a DNA triplet or codon do not change which amino acid is introduced: this is known as a synonymous substitution. Unless the mutation also has a regulatory effect, synonymous substitutions are usually neutral. Some non-synonymous mutations, i.e. mutations that do change the amino acid, are also neutral: these neutral changes are often to a chemically similar amino acid that may not affect the functionality of the overall protein or complex with which it associated. Such mutations may be widely present in individuals within a population through neutral drift.

Neutral mutations can accumulate over time due to genetic drift or genetic draft. According to the neutral theory of molecular evolution, even if most mutations are deleterious rather than neutral or adaptive, the majority of mutations that go on to become fixed as differences between species are neutral.

Many or even most mutations to noncoding DNA are neutral.

Mutation
Mechanisms of mutation
  • Insertion
  • Deletion
  • Substitution
    • Transversion
    • Transition
Mutation with respect to structure
Point mutation
  • Nonsense mutation
  • Missense mutation
  • Silent mutation
  • Frameshift mutation
  • Dynamic mutation
Large-scale mutation
  • Chromosomal translocations
  • Chromosomal inversions
Mutation with respect to overall fitness
  • Deleterious mutation
  • Advantageous mutation
  • Neutral mutation
  • Nearly neutral mutation

Famous quotes containing the word neutral:

    “The United States must be neutral in fact as well as in name.... We must be impartial in thought as well as in action ... a nation that neither sits in judgment upon others nor is disturbed in her own counsels and which keeps herself fit and free to do what is honest and disinterested and truly serviceable for the peace of the world.”
    —Woodrow Wilson (1856–1924)