What is a lemming, exactly? Most of us, I’m guessing, could name few of its basic biological attributes. (It’s a rodent weighing one to four ounces and measuring three to six inches in length that lives in the Arctic.) The primary thing we think we know about lemmings—that they throw themselves off cliffs in inexplicable mass suicides—is actually false. This myth originally arose as a folk explanation for the wide variances in lemming populations from year to year, and was cemented by White Wilderness, a nature film produced by Walt Disney that won the Academy Award for best documentary in 1958. In one sequence, lemmings are shown leaping off a cliff into the Arctic Ocean, destined to drown. “They’ve become victims of an obsession,” intones the narrator. In reality, the lemmings were flown to Alberta by the film’s producers and herded off the cliff.

The popular conception of a lemming blindly rushing to its death does a poor job of describing the animal’s nature, but an excellent job of describing human nature—lemmings has entered the vernacular to denote any group of unthinking followers hastening their own demise. To paraphrase Voltaire’s chestnut on God, since no animal that regularly commits mass suicide exists, it was necessary to invent one. We turn to nature documentaries not to understand nature, but to see our own behavior reflected back at us. The natural world—wild, chaotic, mutable—can be endlessly recut to tell whatever story we need to tell ourselves.

Last November, two days after the election, Ellen DeGeneres played a clip for her viewers that had recently gone viral on the internet: A group of baby marine iguanas in the Galápagos make their way from the sand to the safety of the rocks, but are suddenly beset on all sides by racer snakes. As the iguanas are picked off and devoured, one sprints for cover, only to run into an ambush. Then, just as a snake coils around its body, the iguana miraculously breaks free, squirming out of the death grip. After a series of fantastic leaps, still dodging a tangle of snakes, the iguana finally makes it to safety.

“He made it!” DeGeneres exulted. “That little baby iguana got away!” The audience cheered. Then DeGeneres made the moral of the story explicit for her viewers, who found themselves living, suddenly, in Donald Trump’s America. “And that’s what we’re gonna do,” she assured everyone. “No matter what your snake is, there is hope for your little iguana.”

The clip was part of a promotion for Planet Earth II, which has its U.S. premiere this month on BBC America. It’s the much-anticipated sequel to Planet Earth, the groundbreaking BBC documentary from 2006 whose calming narration by David Attenborough and vivid, high-definition sequences of migrating birds, shark attacks, swimming elephants, bat-catching snakes, and polar bear hunts became a favorite of stoners everywhere. Five years in the making, Planet Earth was produced and released before climate change became Oscar-winning entertainment. The sequel, by contrast, was prepared after David Cameron rode to victory as prime minister in part by arguing that global warming is “one of the biggest threats facing the world.” Planned for release ten years after the original series, Planet Earth II was supposed to arrive, triumphant, as a rising tide against the rising tides of climate change.