Do chimps cooperate even when they’re not related? The traditional answer is no, but primatologist Linda Vigilant explains how genetics is revising this belief.
In this interview from Greenland, glaciologist Mark Fahnestock describes the roar of a 1000-foot iceberg dropping off the Jakobshavn Isbræ into the Ilulissat Icefjord. Includes time-lapse photography of this massive calving event.