&#x27;Junk&#x27; DNA doesn&#x27;t actually contain genes. By definition, a gene encodes a functional polypeptide or RNA. This is different from alleles that are neutral for viability. An example of such an allele might be connected earlobes -- this phenotype is genetically determined, but unless there&#x27;s sexual selection I&#x27;m not aware of, you are correct that we wouldn&#x27;t necessarily expect the alleles involved in this phenomenon to go away. However, they might as a result of an accident of history or genetic drift.