Life's Grand Explosions

Evolution favors grand entrances and dramatic exits. Thanks to the dinosaurs, we’re most familiar with the latter, in the form of sudden extinctions, but there have been equally spectacular, if less ballyhooed, bursts of creation as well. Figuring out just what drives the process has long been a favorite focus of scientific theorizing, and in this past year alone, researchers weighed in with three new theories about possible agents of change, involving underwater volcanoes, gluttony, and the evolution of feces.