Omar Freilla grew up in the South Bronx amid burnt-out buildings, waste transfer stations and power plants. He spent his childhood watching the PBS show “Nature,” dazzled by scenes of pristine wilderness—the rainforest, the mountains and the arctic. “There was one thing that always bothered me about those shows, though,” he recalled in a talk at a Bioneers Conference in San Rafael, California. “You never saw any people on them.”