• asexual
  • In evolutionary genetics, Muller's ratchet (named after Hermann Joseph Muller, by analogy with a ratchet effect) is a process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner. (wikipedia.org)
  • Asexual reproduction compels genomes to be inherited as indivisible blocks so that once the least mutated genomes in an asexual population begin to carry at least one deleterious mutation, no genomes with fewer such mutations can be expected to be found in future generations (except as a result of back mutation). (wikipedia.org)
  • Indeed, the probability that the least mutated genomes in an asexual population end up carrying at least one (additional) mutation depends heavily on the genomic mutation rate and this increases more or less linearly with the size of the genome (more accurately, with the number of base pairs present in active genes). (wikipedia.org)
  • The study looked at sexual, as well as asexual, varieties of a New Zealand freshwater snail (left), Potamopyrgus antipodarum, by sequencing mitochondrial genomes and found that the sexually reproducing snails had accumulated harmful DNA mutations at about half the rate of the asexual snails. (redorbit.com)