A mutagen is a chemical or environmental agent that can alter the specific base sequence within DNA. Although most mutations are considered spontaneous, the rate of mutation can be increased through exposure to mutagens. Mutagens are linked to cancer and can be considered carcinogens. Physical mutagens include ionising radiations such as x-rays and gamma rays. Chemicals that cause alkylation, oxidation and deamination of DNA also cause mutations.
Discovery of Mutagens
The first evidence of agents in the environment increasing mutation probability was shown in Drosophila Melanogaster, a model organism, in 1927 by Hermann Muller. He showed that x-rays were mutagenic using the ClB Method.