Evolutionary Tree Diagram (IMAGE) University of California - Santa Cruz Caption This evolutionary tree shows the split between primate and rodent lineages about 90 million years ago, before the emergence of Alu elements in primates and B/ID elements in rodents. These short interspersed elements evolved independently in the two lineages to play the same role in gene regulation. Credit Bronwyn Lucas Usage Restrictions For use only with news coverage of this research 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.