For example, did it really coincide with a jump in brain size, which would indicate it may have helped make us deep thinkers?īut to consider how fire impacted the development of hominins, researchers must first unearth the basics: the initial fleeting evidence of flames that were in any way tended or used by our ancestors. Understanding when people mastered fire could help archaeologists figure out if and how it contributed to these major events in the evolution of the human body and mind. Plus, tending a blaze and gathering around it could have helped shape us into the social animals we are now. Fire provides protection from predators and a warmth that may have allowed humankind to extend its geographical reach. Roasting foodstuffs meant a calorie-rich diet, which may have fueled our big brains into existence. The question gets at the very root of what it means to be human: Fire is one of the things that pushed human evolution along. Even harder to decipher is whether people were using those fires “regularly,” and whether that means every week, year, or decade. Even if evidence for flames is more certain, it can be tricky to tell if the fire was the result of a natural blaze or a human-made spark, or if people harvested it from a nearby wildfire for their own use. Researchers recently determined that the “burned” darkened wood and reddened sediments found at a site in northern Germany, now a coal mine called Schöningen, were really colored by water exposure and soil decomposition, not ancient flames. Even when signs of potential burning are present, it can be surprisingly hard to understand their exact origin. Evidence of fire is ephemeral: Its traces, in the form of ashes or baked soils, are usually eroded away by wind or water. “In order to find early fire, we have to work really, really hard,” says Michael Chazan, director of The Archaeology Centre at the University of Toronto. It’s a deceptively hard question to answer. That leaves a big gap, with plenty to investigate. It probably wasn’t as early as 2 million years ago-but it almost certainly occurred by 300,000 years ago. Her question is a basic one about a crucial early technology: When did humankind first put fire to work for them, using it regularly for heat and cooking? Hlubik and other archaeologists who sift through the long-cold ashes of fires past cannot say for sure. On her summer expeditions, she collects bits of burned bone and soil samples in the hope of proving her case. Those early people likely butchered animals and fashioned stone tools, and Hlubik, a graduate student at Rutgers University in New Brunswick, New Jersey, thinks they did so around a flickering campfire.
Each summer, archaeologist Sarah Hlubik treks rutted dirt tracks to a dry riverbed in Kenya, following, approximately, in the footsteps of ancient hominins who camped there about 1.6 million years ago.