Fragments of iron pyrite, a rock that can be used with flint to make sparks, were found by a 400,000-year-old hearth in eastern Britain. (Jordan Mansfield | Courtesy Pathways to Ancient Britain ...

Something about a warm, flickering campfire draws in modern humans. Where did that uniquely human impulse come from? How did our ancestors learn to make fire? How long have they been making it?

It's easy to take for granted that with the flick of a lighter or the turn of a furnace knob, modern humans can conjure flames — cooking food, lighting candles or warming homes. For much of our ...