Aphid Endosymbionts Affected by Selection (IMAGE) Drexel University Caption Researchers at Drexel University have revealed the evolutionary forces that affect endosymbiont dynamics in pea aphids. Credit Drexel University/Linyao Peng 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.