Did the tales told by firelight by our ancient ancestors play a role in human evolution?

According to one researcher, Polly Wiessner, from the University of Utah, the answer is "yes." She came to this conclusion after studying a group of Kalahari Bushmen currently living in Botswana and Namibia.

The study looked at data that rounded up conversations among groups of Bushmen, looking at the differences between daytime conversation and the conversation that took place at night around a fire. Weissner found a remarkable contrast between the two kinds of conversations.

Daytime conversations usually revolved around economics and work, including complaints and criticism. However, at night, that changed. Around the fire, Bushmen told stories, talked about people not present at the time, and discussed the nature of the spirit world. There was also singing and dancing.

"There is something about fire in the middle of the darkness that bonds, mellows and also excites people," says Wiessner. "It's intimate. Nighttime around a fire is universally time for bonding, for telling social information, for entertaining, for a lot of shared emotions."

These nighttime exchanges seem crucial for the Bushmen's social institutions, and play a part in how the groups organize themselves and get along. This is their form of social networking, their way of becoming part of a broader world.

The Bushmen are representative of our ancient ancestors because they lead similar lives. They are hunters and gatherers and do not have access to electricity. As our ancestors received fire nearly 1 million years ago and used it regularly after about 400,000 years ago, the Bushmen serve as an example of where we came from and how we, as humans, evolved.

It is this form of social networking that makes humans unique from other primates. Other primates do not form extended communities like we do and this is part of why we evolved as the superior species. Much of that evolution comes from these firelight stories and conversations, the sort of things that require imagination and unique cognitive abilities. This also helped us learn how to form views of other people, including those not in our own immediate circles.

Fire itself changed human evolution because it extended the day. Humans rose up to the challenge of longer days by using those extra hours for entertainment and conversation.

However, for most humans, fire gave way to electricity, which could be changing us dramatically. Because we now have light available at any time of the day or night, we're losing these social interactions, and instead, are working longer hours.

"Artificial light turned potential social time into potential work time," says Weissner. "What happens to social relations?"

Perhaps a new line of research will look at how electricity is affecting human evolution.