Vertebrate eye (IMAGE) University of California - San Diego Caption UC San Diego scientists have traced the origin of a unique protein considered key to the vertebrate’s camera-like vision back 500 million years to foreign bacterial sources. Credit Jenessa Daugherty Usage Restrictions Must be used in conjunction with PNAS paper on vertebrate eye innovation. License Original 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.