A new study adds to the long-running debate over when ancient humans learned to use fire. Evidence from South Africa’s Wonderwerk Cave suggests Homo erectus may have kept burning fires inside caves as early as 1.79 million years ago—far earlier than the oldest
For decades, the question has lingered like smoke over early human history: when did our ancestors really start using fire—and how did they manage it?
Now, a new study in PLOS One points to Homo erectus using fire inside caves as early as 1.79 million years ago, based on signs of burning preserved in ancient layers at Wonderwerk Cave in South Africa.
The finding matters because fire wasn’t just a convenience. It could have helped early humans cook food—making digestion easier and freeing up more energy for brain development. It also would have provided warmth and may have deterred predators. Yet exactly when and how hominins began relying on fire has remained murky.
The oldest direct evidence of ancient hominins actually making fire. the study notes. comes from a 400. 000-year-old Neanderthal site in England. Earlier ancestors such as Homo erectus likely couldn’t make fire from scratch. Instead, anthropologist Michael Chazan of the University of Toronto says they probably captured it from slow-burning bunches of grass.
Nick Ashton. an archaeologist at the British Museum and senior author of the Neanderthal fire research. praised the strength of the new evidence for the earliest known fires. He also warned that the authors of the newer work remain uncertain about exactly when the burning occurred. giving a wide time range between 1.79 million and 1.07 million years ago.
Chazan and his colleagues have been working on Wonderwerk Cave for about two decades. In 2012, they found signs of fire use—burned bones, ash, and sediment—in the million-year-old Stratum 10 archaeological layer at the site.
The team then turned to the layer below, Stratum 11, which can be up to 1.79 million years old. There, they looked for evidence tied to burning by studying fossilized barn owl pellets. They analyzed changes in texture and color linked to burning. and the distance helped tighten the interpretation: the pellets were about 30 meters away from the cave’s entrance. allowing the researchers to rule out incineration by a natural wildfire.
Stone hand axes also appeared in Stratum 11. The researchers suggest that individuals of Homo erectus living in the cave may have burned the pellets to help keep the fire going longer inside.
The cave’s bones provided additional clues. Researchers found ashy white bones that appeared to have been exposed to high heat. along with what looked like charred black and brown bones. But bones can look burned for reasons unrelated to fire; natural and chemical processes such as manganese staining or fluoridation can mimic burn marks in fossilized material.
To get around that problem, the team used Fourier transform infrared (FTIR) spectroscopy to identify the organic and inorganic substances present in the dark-colored bones from Stratum 11. That work indicated that four of the bones were burned.
They then analyzed the gray-white bones using a luminescence technique. The method can reveal whether a bone has been burned or not: burned bones undergo chemical changes that enable them to absorb short-wavelength light. like blue light. and emit longer-wavelength light. like red light. After exposing the bones to high-energy blue light, the team used an optical filter to check which samples glowed red. That showed some 21 of the 39 white-grayish bones in Stratum 10 had burned, and all 32 from the layer below had burned.
Still, one of the hardest parts is what the evidence can’t tell. It’s impossible, Chazan says, to know why Homo erectus kept a fire burning inside the cave.
Another key constraint comes from whether fire was being used in a way that resembles cooking. Geologist Yolanda Fernández-Jalvo of the National Museum of Natural Sciences in Spain ruled out cooking within Wonderwerk because fire was only brought in opportunistically—it was not domesticated yet.
What happens next is now on the team’s schedule. This summer, the researchers plan to look for additional clues and try to figure out how Homo erectus got the fire into the cave in the first place.
The question at the heart of the study isn’t just whether fire burned there long ago. It’s whether the earliest humans were already learning to control it—one cautious, smoky step at a time.
Homo erectus fire use Wonderwerk Cave South Africa PLOS One ancient humans barn owl pellets archaeology Neanderthal fire evidence FTIR spectroscopy luminescence technique
So basically they found cave ash and now we’re sure they were cooking? Sounds like a guess to me.
1.79 million years ago?? That’s wild. I always thought fire was way later like Neanderthals or something. Wonderwerk Cave sounds like the smoking gun.
Wait, if Homo erectus “couldn’t make fire from scratch” then how did the cave even have fires? Wouldn’t that mean someone else had to bring it in or something? Also the article says 1.79 to 1.07 million years which is a HUGE gap, so like… when was it actually?
This is why I don’t trust those studies, they always say “uncertain” at the end. Like ash could be from random stuff, right? Predators deterred?? Humans were that organized that long ago? Idk, but the idea that they managed fire in caves is kinda cool.