Extremotolerance

True hunger for extremity is rare. Most animals that can temporarily survive in an extreme environment would prefer a less stressful one. Extremophiles—species that thrive in extremes—make up a much smaller percentage of life on earth, occupying places whose conditions would kill most other organisms. But beyond extremophilia, there is a second category: organisms that don’t love extremes but manage to be exceptionally resilient. For example, the tardigrade, a micro-animal that lives all across the world, from the tallest of the Himalayas to the abyssal deep. These organisms exist among us, functioning well in temperate environments, but they can also withstand many forms of harshness—freezing, aridity, toxic chemicals, radiation, lack of oxygen, salinity, pressure. Biologists refer to tardigrades as extremotolerant.