Abby Stewart sometimes thought that she was born to be a teacher. At the small college in Colorado where she was an instructor in the biology department, she enjoyed preparing lectures for business or history majors who were simply fulfilling a requirement by taking her course in anatomy and physiology. She worked hard to prove to these students that they should still care about biology, and one way she captured their attention was by describing natural phenomena that, at first glance, might seem peculiar. She revealed that clown fish—like Nemo, in the Pixar movie—are hermaphrodites, starting out as male but sometimes becoming female as they mature. And she talked about how fungi send out subterranean tentacles, which fuse with those of other fungi. When you eat a mushroom, Abby told her students, you are eating combined sex organs.