Sample preparation (IMAGE) Purdue University Caption Erangi Heenkenda, co-lead author of the PNAS paper who received her PhD in forestry and natural resources from Purdue this month, prepares to take a sample from a frozen pupfish that will be used for genome sequencing. Credit Purdue Agricultural Communications/Tom Campbell Usage Restrictions News organizations may use this image in reports about the work of Purdue University’s Andrew DeWoody and his associates. 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.