When primatologist Jill Pruetz found herself threatened by wildfires in the savannas of Fongoli, Senegal, in 2006 she had two options: stay with the chimpanzees she was studying, or run. She chose the chimps. The primates were calm, and--with her in tow--they carefully made their way around the blaze. "I was very surprised at how good they were at judging the threat and predicting the behavior of fire," says Pruetz. The chimps' actions, she would later report, set them apart from other nonhuman animals--and they may reveal the evolutionary origins of how we came to master fire.
According to Pruetz, who works at Iowa State University in Des Moines and has studied the Fongoli chimps since 2001, there are three steps to mastering fire: conceptualizing it, starting it, and containing it. Most animals fail the first step, reacting by instinct. West African reed frogs flee at the sound of fire, brush-tailed bettongs in Australia become dazed and confused, and stress hormones jump in African elephants.
Chimps, on the other hand, take a more nuanced approach. Pruetz witnessed the primates calmly moving around wildfires on two occasions. Other times, the chimps rested and groomed while smoke began to obscure the sun. They seem to realize, says Pruetz, that fire has a behavior--just like another forest animal--and that its movements can be predicted.
Pruetz and paleontologist Thomas LaDuke of East Stroudsburg University in Pennsylvania reported their analysis of these observations online 21 December in the American Journal of Physical Anthropology. They do not contend that chimps will one day start and contain fires, though captive apes can start fires with a cigarette lighter (see video, start at 6:05). But the chimps' behavior may reveal a primitive hominid trait.
A key to their argument is that the chimpanzees, like humans, can control their fear of fire. Sociologist Joop Goudsblom, an emeritus professor at the University of Amsterdam who has published extensively on the evolution of human mastery of fire, says this description of the Fongoli chimps comes close to how he imagines early hominins behaved. "To manipulate fire and use it for your purposes you have to step back from it, not run away," says Goudsblom, who speculates that early humans also saw fire as something alive. "It sounds a bit odd, but it makes sense if you go back a million years. Somehow, we managed to find the proper combination of curiosity and foresight--which is what's needed if you want regular association with fire."
Pruetz and LaDuke suspect that other primates and "cognitively sophisticated" species might similarly conceptualize fire. But Pruetz says next to nothing has been published on the subject. "I was really surprised at how little information there was available," she says. Perhaps her findings will spark more interest in the topic.