A mutagen is a physical, chemical, or biological agent able to increase the occurrence of mutations above the spontaneous level. Mutations produced by the action of mutagens are called induced mutations. The effect of most mutagens is due to their ability to modify a particular nucleic acid base or to become incorporated into the nucleic acid. As a high amount of mutations have deleterious effects on fitness, exposure to mutagens usually has negative consequences. Nonetheless, at early evolutionary stages, certain environmental mutagens could have had a positive effect, increasing the extent of genetic diversity accessible to natural selection.
Among chemical mutagens, the most important are nucleic acid base analogs – which due to their similitude with natural bases can be incorporated into DNA or RNA during replication – and compounds that produce chemical alterations in the bases (Drake and Baltz 1976). The result in both cases is the induction of erroneous base...
KeywordsBase analogs Evolution Genetic damage Genetic diversity Mutation Radiation
References and Further Reading
- Friedberg EC, Walker GC, Siede W, Wood RD (2005) DNA repair and mutagenesis. ASM Press, Washington, DCGoogle Scholar