Imagine a world sixty thousand years in the past. The day begins not with a sunbeam, but with a shiver of cold against the skin. You are part of a small, tightly-knit band of early humans, huddled for warmth in a shelter of woven branches and animal hides. Before the sun graces the horizon, the singular, driving purpose of the day is already clear: survival.
Every meal is a victory wrested fro...
