Tikal (3 of 3) (IMAGE) University of Cincinnati Caption University of Cincinnati researchers Nicholas Dunning, Vernon Scarborough and David Lentz collect sediment samples for DNA analysis. Credit Liwy Grazioso Sierra 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.