How do predators and prey drive each other's evolution?

The answer

Predator-prey coevolution, sometimes called an evolutionary arms race, is one of the most powerful engines of adaptation in nature. The rough-skinned newt and the common garter snake illustrate this perfectly: the newt produces tetrodotoxin (the same toxin found in pufferfish), and certain garter snake populations have evolved resistance to this toxin, which in turn drives the newt to produce ever-higher toxin levels. Cheetah speed evolved in response to fast gazelles, and gazelle agility evolved in response to cheetah pursuit. Some prey species evolve features that specifically counter a predator's adaptations: moths developed ultrasonic ears specifically to detect bat echolocation, and some can even jam bat sonar with their own ultrasonic clicks. This ongoing reciprocal adaptation, described by the Red Queen hypothesis, explains much of the dizzying diversity and complexity of life.