Learning the secret of fire was a tremendous leap forward for early humans. Fire provided light and heat, cooked food and kept predators at bay. In later epochs, it was used to clear land for agriculture, make pottery and forge metal. Though dependable techniques for making fire were not available until around 7,000 BC, the unearthed remains of simple hearths provide unquestionable evidence that controlled fire was in use at least 500,000 years ago.

Primitive town centers were little more than the fire pits where members of a nomadic tribe would gather socially, perhaps to celebrate a successful hunt. Food meant survival, so when hunters returned with a kill, it was cause for rejoicing.

Given the immense importance of obtaining food, tribes must have come into conflict with one another for control over fertile hunting grounds and foraging areas, especially in times of overall scarcity. These early struggles for survival were the likely precursors of the large-scale battles and wars that have dogged our species throughout recorded history.