Fires are paving the way for humans to evolve into the species we are today. Scientists think that without a control over fire, humans would probably never have developed large brains and the benefits that come with it. But when did people first discover how to use fire?
“That’s a tricky question,” said Ian Tattersall, a paleoanthropologist and curator emeritus of human descent at the American Museum of Natural History in New York City. “Maybe the evidence for fire does not prove so good, and what we see are just the remains of what used to be a much richer plate. But again, that’s guesswork. We do not know.”
What experts know is that around 400,000 years ago, fire began to appear much more frequently in the archaeological record in Europe, the Middle East, Africa and Asia, according to a 2016 article in the journal Philosophical Transactions of the Royal Society B. Experts consider these fires to be widespread, although evidence pages are still relatively sparse.
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At least two isolated sites show former humans using fire 400,000 years ago, Tattersall said. For example, on a site in Israel dating back some 800,000 years, archaeologists have found hearts, flints and burnt wood fragments, according to a 2012 study in the journal Science. On another site, the one called Wonderwerk Cave in South Africa, scientists found evidence that humans used fire about 1 million years ago, according to a 2012 study in the journal Procedures of the National Academy of Sciences. In that cave they found remains of burning bones and plants and what turned out to be hearts.
“Where the evidence comes from the site is really far back in the cave,” said Sarah Hlubik, a paleoanthropologist and postdoctoral researcher at George Washington University in Washington, DC. “Even a landscape fire that has been circulating is not reachable that far back.” In other words, there is little chance that the data is a fluke, even if they are isolated in space and time.
Although Miracle is the first site where most experts agree that humans used fire, in theory they should have used it much earlier. About 2 million years ago, the gut of the human ancestor Homo erectus began to shrink, suggesting that something like cooking digestion made a lot easier. Meanwhile, her brain was growing, which requires a lot of energy. “Where else would you get the energy without using fire to cook food?” Tattersall told Live Science, referring to eating meat and vegetables.
To make that argument, Hlubik is looking for signs of ancient controlled fires at sites in Koobi Fora, a region in northern Kenya rich in paleoanthropological remains that are about 1.6 million years old. So far, she has found burning bones clustered with other artifacts there. Burning sediment was compiled separately, suggesting that there was one area for fire conservation and another area where old people spent most of their time.
“At this point, I’m sure to say, ‘Yes, there was fire that was used by people on this particular site,’ ‘Hlubik said. “The next phase of the investigation is then to say: ‘How many other sites in the region also have evidence of fire?'”
But not all experts agree with Hlubik. The fires at the site they are digging may not have been started by humans. It is possible that the evidence could have originated from buses that were torched by natural wildfire.
When fires broke out, humans’ catching and controlling fires – or creating their own fires – had a massive impact on the evolution of the species. Tattersall said it is likely to extend life span, make people more social by giving them a place to gather and co-invent clothing. Fires are also likely to increase human cognition, Hlubik added. “The benefits of using it reinforce the cognitive gains you’ve already made and then create more. Because fire is a complex thing,” she said. “You can get a lot of pain if you use it incorrectly.”
Originally published on Live Science.
