Primate Skulls (IMAGE) Duke University Caption This shows the skulls of a human, a gorilla and a macaque -- three of the species in which researchers looked at the genomics of enamel evolution. Credit Les Todd 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.