In the 1970s, scientists proposed what has become known as the Gaia Hypothesis: the idea that earth is best understood not as a passive substrate or background to life but as a life form in its own right. Our guest, journalist Ferris Jabr, believes the time has come to revive that idea. To understand how sentient creatures have evolved on this planet, he suggests, is not only to grasp that animals—human and otherwise—are offshoots of an evolutionary tree; it’s to see the tree itself as one element of a dynamic, interrelated organism. We speak with Jabr about the art of science reporting, the limits of life, and what the white cliffs of Dover are made of.