 The name emphasizes the fact that the genetic background, or genomic environment, of a neutral mutation has a significant impact on whether it will be preserved (genetic hitchhiking) or purged (background selection) from a population.In some cases, the term background selection is used broadly to refer to all forms of linked selection, but most often it is used only when neutral variation is reduced due to negative selection against deleterious mutations.Background selection and all forms of linked selection contradict the assumption of the neutral theory of molecular evolution that the fixation or loss of neutral alleles is entirely stochastic, the result of genetic drift.