variation이 있으나 selectively advantage 하지도 disadvantage 하지도 않은 variation을 의미합니다. 

neutral 의 오타입니다 ㅠ

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.