A closer look
Drop an invasive species into a predator-free paradise, and they'll aggressively consume their way to an apocalypse. In 1944, the Coast Guard left 29 reindeer on St. Matthew Island. With infinite lichen and zero wolves, the population exploded to 6,000 by 1963 in a textbook case of ecological overshoot. The animals devoured their entire food supply before a harsh winter hit, starving the herd down to just 42 females and one completely sterile male. Nature's ultimate boom-and-bust startup.
