Logan Pallin (IMAGE) University of California - Santa Cruz Caption UCSC postdoc Logan Pallin determined humpback pregnancies by taking small tissue samples and testing for progesterone. Credit © Chris-Johnson/WWF Usage Restrictions For use only with news coverage of this research 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.