For life to survive, it must adapt and readapt to an ever-changing Earth. The discovery of the Antarctic icefish has provided a stunning example of adaptation in an environment both hostile and abundant, where the birth of new genes and the death of old ones have played crucial roles. Researchers Bill Detrich, Christina Cheng, and Art DeVries have pinpointed the genetic changes that enable icefish to thrive without hemoglobin and red blood cells and to avoid freezing in the icy ocean.