Cooption Model (IMAGE) University of Pittsburgh Caption The original enhancer DNA (left) mutates to contain an additional protein-binding site (center), which causes low-level gene activity in a new location, illustrated by the light blue spine. Subsequent mutations (right) build on that activity to produce a novel characteristic, or the dark blue spine. Credit M. Rebeiz 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.