This activity explores the research presented in the short film The Making of the Fittest: The Birth and Death of Genes, which illustrates how gene duplications and mutations have allowed some fish to adapt to extreme environments.

The discovery of the Antarctic icefish has provided a stunning example of adaptation in an environment that is both hostile and abundant. Scientists 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. The “Student Handout” probes students’ understanding of the key concepts addressed in the film. The “Educator Materials” document provides suggested pause points in the film with questions for students, background information, and detailed discussion points; a list of related resources and references; and an answer key for the “Student Handout.”