Photo 3 (IMAGE) University of Chicago Caption University of Houston Prof. Alamgir Karim first suggested rain as a possible source of distilled water that would have existed in the era when protocells first formed. Credit University of Houston 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.