Wikipedia

Mutational meltdown

Mutational meltdown (not to be confused with the concept of an error catastrophe[1]) is the accumulation of harmful mutations in a small population, which leads to loss of fitness and decline of the population size, which may lead to further accumulation of deleterious mutations due to fixation by genetic drift.

A population experiencing mutational meltdown is trapped in a downward spiral and will go extinct if the phenomenon lasts for some time. Usually, the deleterious mutations would simply be selected away, but during mutational meltdown, the number of individuals thus suffering an early death is too large relative to overall population size so that mortality exceeds the birth rate.

The accumulation of mutations in small populations can be divided into three phases. In the second phase a population starts in mutation/selection equilibrium, mutations are fixed at a constant rate through time, and the population size is constant because the fecundity exceeds mortality. However, after a sufficient number of mutations have been fixed in the population, the birth rate is slightly less than the death rate, and the population size begins to decrease. The smaller population size allows for a more rapid fixation of deleterious mutations, and a more rapid decline of population size, etc.

See also

References

  1. ^ Eigen, M (15 October 2002). "Error catastrophe and antiviral strategy" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 99 (21): 13374–6. doi:10.1073/pnas.212514799. PMC 129678. PMID 12370416.

Further reading

This article is copied from an article on Wikipedia® - the free encyclopedia created and edited by its online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of Wikipedia® encyclopedia articles provide accurate and timely information, please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.

Copyright © 2003-2025 Farlex, Inc Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.