Giant clams write a “diary” of their lives in their shells – recording details of not only their own biology, but also the environment and climate conditions around them. Dan Killam, a postdoctoral researcher at the University of Arizona, studies these amazing bivalves up close in the controlled conditions of the university’s Biosphere 2, where a huge indoor tank replicates a tropical ocean. In this way, Killam combines his two greatest scholarly passions: undersea creatures and climate change.