A neutral mutation, which can also be called a silent mutation, is, like all genetic mutations, a change in the deoxyribonucleic acid (DNA) that comprises the heredity material in all living organisms. Specifically, a neutral mutation is a mutation that does not affect the particular phenotype whose expression is under the genetic control of the mutated gene. An example of a neutral mutation would be the replacement of one base with another in the deoxyribonucleic acid comprising the gene, with the replacement having no effect on the protein encoded by the gene.

Neutral mutations can be divided into two kinds. First, the mutation can occur in a region of DNA called junk DNA--a region of DNA that is nonfunctional in terms of the phenotype of the organism. Only mutations in the coding regions of DNA contribute to the mutational change in organisms over time. The second...