Mesocosms (IMAGE) Duke University Caption Mark Wiesner stands with rows of mesocosms -- small, manmade structures containing different plants and microorganisms meant to represent a natural environment with experimental controls. Credit Duke University 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.