Mutation Timer Built into DNA (VIDEO) Duke University This video is under embargo. Please login to access this video. Caption Scientists have discovered that DNA contains a kind of built-in timer that clocks the frequency with which mutations occur. They show that DNA bases can shape-shift for a thousandth of a second, transiently morphing into alternative states that allow the molecule's replication machinery to incorporate the wrong base pairs into its double helix. Such mismatches, though rare, serve as the basis of genetic changes that drive evolution and diseases like cancer. Credit Al-Hashimi Lab, Duke University 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.