Sea urchins are weird, spiky, and at first glance, don’t seem all that interesting. But beneath that uncharismatic appearance is a creature that has been central to scientific discoveries? that changed the way we understand the natural world. In part 1 of the urchin’s tale, I highlighted what these unassuming critters have taught us about the processes that shape ecosystems. In part 2, I will explore their role in developing our understanding of the fundamental processes that shape us, as well as the other animals that share our world. . . .