Illustration (IMAGE) University of Chicago Caption A new paper from the UChicago Pritzker School of Molecular Engineering, University of Houston Chemical Engineering Department and Chicago Center for the Origins of Life suggests rainwater could have helped create a meshy wall around protocells 3.8 billion years ago, a critical step in the transition from tiny beads of RNA to every bacterium, plant, animal, and human that ever lived. Credit UChicago Pritzker School of Molecular Engineering / Peter Allen, Second Bay Studios Usage Restrictions N/A License Original 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.