Far, far below the surface of the ocean, stretching deeper than sunlight can penetrate, deeper at points than Mount Everest is tall, is the largest and most mysterious ecosystem on the planet: the deep sea. The water there is nearly freezing, the pressure enormous. Light is either scarce or completely absent. For much of human history, this punishing environment was thought to be completely devoid of life. It’s only in the last century and a half that scientists have realized the opposite: There are likely more animals down there than…
