Oscillations (image) University of Wisconsin-Madison Share Print E-Mail Caption When the researchers extended their experiment to 40 generations, they spotted repeating oscillations in the concentration of phosphate, one of the key starting materials in their chemical soups. These oscillations suggest the development of feedback loops, which are one characteristic of life. Credit Image courtesy of David Baum lab Usage Restrictions None Share Print E-Mail 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.