∞ generated and posted on 2016.12.25 ∞
Polymorphisms that are a consequence of natural selection not being sufficiently strong relative to genetic drift to modify the frequency of specific alleles.
| Neutral Variation means that multiple alleles are present at a given genetic locus because those alleles are not distinguishable by natural selection. |
These are alleles, in other words, which neither greatly add to nor greatly detract from organism fitness, and it is the collection of such alleles found within a population that can be described as representing neutral variation. See by contrast detrimental allele as well as beneficial allele.
Alleles that have a neutral impact on organism fitness also tend to accumulate within populations precisely because they are not being purged by natural selection. See also neutral allele as well as neutral mutation.