Yeonwoo Park (IMAGE) University of Chicago Caption Graduate student Yeonwoo Park holding a tube containing a library of thousands of mutants of a 700-million-year-old gene. Credit Joe Thornton, UChicago Usage Restrictions Please credit 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.