The earliest evidence of our hunter-gatherer ancestors using fire in a controlled way is from about 3- to 4-hundred-thousand years ago. It was most likely for cooking and warding off predators. But new research by Dr. Polly Wiessner, from the Department of Anthropology at the University of Utah in Salt Lake City, suggests that, at some point, fire and firelight extended the day and gave rise to the culture of storytelling, which, in turn, fostered a sense of community and reinforced social traditions. As this tradition is still carried on by contemporary hunter-gatherers - the Bushmen of Africa's Kalahari Desert - Dr. Wiessner recorded and analyzed their day and night-time conversations Day-time conversation were largely gossip, complaints and criticisms, often related to events and people involved in the hunt. But at night, the conversations were mostly stories, often accompanied by singing and dancing, that stretched the imagination and broadened the sense of community beyond the village.