
How did we cope? By getting smarter. The neurophysiologist William Calvin argues persuasively that modern human cognition—including sophisticated language and the capacity to plan ahead—evolved in response to the demands of this long age of turbulence. According to Calvin, the reason we survived is that our brains changed to meet the challenge: we transformed the ability to target a moving animal with a thrown rock into a capability for foresight and long-term planning. In the process, we may have developed syntax and formal structure from our simple language.