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 seashore is a sort of neutral ground, a most advantageous point from which to contemplate this world. It is even a trivial place. The waves forever rolling to the land are too far-traveled and untamable to be familiar. Creeping along the endless beach amid the sun-squall and the foam, it occurs to us that we, too, are the product of sea-slime.”
    —Henry David Thoreau (1817–1862)