Multi-nucleotide Mutation (IMAGE) Indiana University Caption If mutations only happened one-at-a-time, three separate mutation events would be required to convert ACT to GGA (top). Multi-nucleotide mutation, facilitated by error-prone polymerases, can allow for 2 to 9 simultaneous mutations, opening up whole new considerations for protein evolution. Credit Image by Dan Schrider Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.