Earliest use of fire thrown back by almost a million years, to 1.8 million years ago
New study doubles the timeline of fire use by early humans in Wonderwerk Cave, but why they brought it there remains unclear, and what do owls have to do with it?
Haaretz
75
13 min read
0 views
New study doubles the timeline of fire use by early humans in Wonderwerk Cave, but why they brought it there remains unclear, and what do owls have to do with it?
How hominins came to adopt fire is unclear, given that any animal's natural reaction to flames should be terror. Yet at some point, early humans overcame the fear and began to bend fire to their will, ultimately resulting in the military-industrial complex.
We cannot know why or how we overcame it, though we assume fire exploitation began with "harvesting" naturally occurring fire: see fire, help oneself to a flaming branch or bundle of grass, take elsewhere and apply. There is general agreement that the earliest adopters of flame didn't know how to light it. If there was fire in a cave, they "harvested" it and brought it there.
But we can ask when. Until now, the earliest known fire use was a million years ago, identified in South Africa's Wonderwerk Cave. Now a new study revisits the cavern and almost doubles the timeframe for the earliest fire found there, to about 1.8 million years ago, by identifying burned animal bones from that time. The results were published by M. Dolores Marin-Monfort of Consejo Nacional de Investigaciones Científicas y Técnicas, with Liora Kolska Horwitz of the Hebrew University of Jerusalem, Michael Chazan of the University of Toronto and Yolanda Fernández-Jalvo of the Natural Science Museum of Madrid, and colleagues, in the journal PLOS One.
The Wonderwerk Cave entrance.Credit: The Wonderwerk Cave Project
The Wonderwerk Cave entrance.Credit: The Wonderwerk Cave Project
The new research didn't set out to revisit the dating in Wonderwerk per se, Fernández-Jalvo explains. The team's purpose was to investigate whether bones found in the archaeological layer, Stratum 11, spanning 1.07 to 1.79 million years ago, were burned. They succeeded in doing this using two methods, including a new technique based on luminescence emitted by burned bones when exposed to light filters. The team is 100 percent confident in their result, she adds.
Haaretz Podcast
In Mamdani's NY, Israel's far right used Israel parade to flex their muscles
Haaretz Podcast
In Mamdani's NY, Israel's far right used Israel parade to flex their muscles
total-- : --time0:00
Previously, in 2012, the Wonderwerk Cave team reported on million-year-old fire in a layer called Stratum 10. The new work relates to the deeper, older Stratum 11, some 80 centimeters below Stratum 10 and tens of thousands of years older.
A new technique based on the luminescence emitted by burned bones when exposed to UV light filters.Credit: The Wonderwerk Cave ProjectA new technique based on the luminescence emitted by burned bones when exposed to UV light filters.Credit: The Wonderwerk Cave Project
The key bone samples exhibiting fire use in Stratum 11 are small rodent bones from the bottom of that layer, i.e., closer to the 1.79-million-year date, Kolska Horwitz explains. In future work, they plan to analyze the deepest layer of all, Stratum 12, for evidence of fire.
Interestingly, a white sediment layer in Stratum 12 was proposed in the 1970s by another archaeologist as representing a hearth. It wasn't, the team says. Now, in their present study, they report that there is evidence of fire in the overlying layer. Perhaps, down the line, the original researcher will be proved right, if not for the right reason.
So, what have we? Evidence that the hominins living in Wonderwerk Cave almost 2 million years ago used fire throughout this time span. They had already overcome the fear and understood how to use fire, if not how to start it.
"What this shows is human engagement with fire," co-author Chazan says by Zoom. As for how engagement with fire began, "there as many opinions as archaeologists who work on this topic, because the evidence isn't amazing. My perspective is we have no evidence for people making fire until much later, and no evidence of fire being maintained for very long periods of time, as we see at Qesem Cave in Israel from around 400,000 years ago," he says.
Where lightning strikes 1,000 times
"What we see at Wonderwek is an early stage of engagement with fire, where natural fires are part of the environment, as they have been for hundreds of millions of years. All ecosystems and animals and plants interact with fire. Humans started to do something new about 2 million years ago and this is what we start to see in the archaeological record at Wonderwerk," Chazan says.
Note that if ancient fire evidence is in an open-air site, not a cave, it's hard to nail down whether it was caused by hominin agency or nature. At Gesher Benot Ya'akov, however, actual hearths on the riverbank are claimed based on repeated use of the same combustion areas over thousands upon thousands of years. Lightning may strike twice in the same spot, but surely not thousands of times.
The Wonderwerk Cave.Credit: The Wonderwerk Cave ProjectThe Wonderwerk Cave.Credit: The Wonderwerk Cave Project
Kolska Horwitz stresses that at Wonderwerk, the team is not suggesting that the hominins had "domesticated" fire – not 1.8 million years ago and not one million years ago. Maybe they did, but we have no smoking matchbox, and they had ample opportunity to help themselves to Nature's wrath. Wildfire is common in the African savanna. So the team thinks the hominins carried burning vegetation into the cave.
What sort of vegetation? One assumes a burning branch, but the hominins lived in a savanna bushland, and the evidence in both Strata 11 and 10 actually suggests that the hominins introduced grasses, Chazan says. How would they transport flaming grass? Wouldn't it burn up in a flash? Perhaps not if it was tightly bunched up, he suggests – grab a handful of grass, carefully let the tips ignite and race for the cave? Maybe.
Why did they take the fire? We don't actually know. To deter scavengers and predators is one possibility; sensible animals steer clear of fire. To cook? It has been posited that the evolution of meal processing didn't start with cooking per se, but with smoking leftover meats, so maybe they did that, and/or cooked. For warmth, to chase away the night – we cannot know. But nearly two million years later, we appreciatively applaud their initiative. Never mind imagining life without electricity; try imagining life without fire.
Who's whoo in Wonderwerk
Excavations in Wonderwerk, which is inland in the Kalahari Desert, began in the 1940s. Starting in the 1970s, excavations led by the archaeologist Peter Beaumont of the McGregor Museum in Kimberley, South Africa, revealed the incredible 2-million-year sequence of occupation, the longest known habitation in a cave anywhere, and a stunning gradient of tools, from crude Oldowan-style, or "pebble" tools at the bottom, to more refined Acheulean oval and pear-shaped hand-axes as time advanced.
Excavations in Wonderwerk revealed an incredible 2-million-year sequence of occupation and a stunning array of tools.Credit: The Wonderwerk Cave ProjectExcavations in Wonderwerk revealed an incredible 2-million-year sequence of occupation and a stunning array of tools.Credit: The Wonderwerk Cave Project
The thinking is that after splitting from the chimpanzee line, the hominin set evolved in savanna conditions, and there is quite the question about why we entered caves in the first place. Based on the Wonderwerk case, Fernández-Jalvo has an interesting hypothesis based on the discovery of "scorched microfauna" in Stratum 11.
"Finding signs of fire on small mammals is curious," she points out. Were the hominins crunching on roast vole? Maybe, but the parsimonious explanation begins with the owl pellets carpeting the cave floor.
The Wonderwerk Cave floor with concentrations of owl pellets marked with red arrows.Credit: The Wonderwerk Cave ProjectThe Wonderwerk Cave floor with concentrations of owl pellets marked with red arrows.Credit: The Wonderwerk Cave Project
When an owl eats, any bones and fur or scales that it cannot digest form a compact pellet in its stomach that the bird throws up, she cheerfully explains. Said pellets are a veritable richness of flammable organics. The burned bones come from mice and whatever else the owls ate; they threw up indigestibles as pellets, and then the hominins came along and possibly discovered that fire they opportunistically collected would burn longer on the floor of the cave than in the open air, she proposes.
That is because the pellets covering the cave floor would catch fire, burn richly and make the fire last longer. "That is the interest Homo erectus had in the cave – they could take advantage of refuge and could get fire to last longer," she sums up. And thus began the cave life.
As for cooking mice, voles or anybody else, Kolska Horwitz notes that they can't categorically say the occupants were doing that, despite the burned micromammals from 1.8 million years ago in Stratum 11 or scorch marks on large-animal bones found in Stratum 10.
Stages of burning in bone samples, from unburned beige bone at left to heavily burned white bone at right.Credit: The Wonderwerk Cave ProjectStages of burning in bone samples, from unburned beige bone at left to heavily burned white bone at right.Credit: The Wonderwerk Cave Project
"We assume they cooked," she says. "But it's difficult to determine whether burned bones were the result of intentional cooking as opposed to accidentally falling onto a fire. We are being cautious because there are such enormous implications for evolution. Also, we have no 'constructed combustion area,' aka fireplace, just burned bones."
Chazan is even more cautious. "There is a model," he says. "About 2 million years ago people started using fire and that changed everything. Suddenly they had energy from cooked food that had not been available before. But I know that at Wonderwerk, that is not the signature we're seeing. We are not seeing fires lit at all seasons, or in every occupation level. They're more ephemeral."
So what have we? A turning point in humanity's road that may have been less about roasting the meat – though once that delight was discovered, there was no turning back – and more about warmth and chasing away the demons of the night.
Slow-release owl pellet
Clearly, owl vomit does not a bonfire make. But were the owl pellets used as supplementary fuel? "Some of us think the hominins were using the pellets as kindling to keep the fire going," Kolska Horwitz sums up, exactly as people feed fires with dried cow dung to this day. "It's not that the entire floor burned. We have small concentrations of burned materials and think those were the points where people were burning pellets instead of, say, plants, to keep the fire going." These concentrations do not add up to a hearth, she says.
Owl pellets from the Wonderwerk Cave's floor.Credit: The Wonderwerk Cave ProjectOwl pellets from the Wonderwerk Cave's floor.Credit: The Wonderwerk Cave Project
It must have smelled horrible too, she adds, but that's a study for another day.
Chazan doesn't agree that the pellets were tapped for fuel. "The hominins were not gathering owl pellets. They'd go up in seconds – they're just fur and bones - they really are disgusting," he adds. Yet if they didn't flash into fire but were more like a slow-release medicine capsule, and gradually charred beneath the burning branch, they could help the fire last longer.
And thus began the cave life, perhaps – suddenly, warmth and illumination that lasts longer under shelter, nurtured by owl vomit. Wonderwerk may be the world's first home, so why not throw in a cozy fire, nurtured by raptor ejecta? Perhaps the icon of real estate agents worldwide should be the owl.
Pellet from a Long-eared Owl (Asio otus) and its components.Credit: BastienMPellet from a Long-eared Owl (Asio otus) and its components.Credit: BastienM
The prehistoric pyromaniac
Who was it that brought fire into Wonderwerk Cave? Not a single hominin bone has been discovered there, Kolska Horwitz notes. Moreover, we now know the tree of human evolution is less a linear sequence and more like a burning bush, and South Africa had quite the selection of possibly relevant hominids, such as:
Australopithecus sediba, which was there almost 2 million years ago, but didn't make tools and wasn't even on the hominin line.
Reconstruction of Australopithecus afarensisCredit: ShutterstockReconstruction of Australopithecus afarensisCredit: Shutterstock
Homo erectus (or Homo ergaster), whose remains were identified at Drimolen, north of Johannesburg, aka the "Cradle of Humankind," from about 2 million years ago. Erectus is one of the hominins who expanded out of Africa, passing through Israel and crossing into Eurasia, where it only died out about 100,000 years ago.
Homo habilis, who is primarily known from East Africa, but there are possible similar forms in South Africa including at Sterkfintein, Swartkrans, and Drimolen. But maybe they weren't Homo habilis, maybe they were late australopithecines. Human evolution research is fun.
Also, there was Paranthropus, a burly australopithecine that coexisted with early Homo, and Australopithecus africanus which overlapped in South Africa with early Homo and Paranthropus. In short the place was crawling with hominins. "But our money is on the pyromaniac Homo erectus," Kolska Horwitz sums up.
The results aren't surprising, in the sense that the Wonderwerk team thought the evidence for fire earlier than a million years was there – "We saw burned bones," says Kolska Horwitz – black charring and white calcination. Even Beaumont thought so in the 1970s. "He didn't test the theory, but he was a very good archaeologist, so we took what he says seriously," she adds. True, "what he thought was the sign of fire wasn't, but the fact that he suggested it made us receptive to the concept."
Kolska Horwitz shares that the luminescence technology they used to identify burned bones was also employed after October 7, 2023, to find bodies of terror victims in arson sites. This basically forensic methodology helped find the last few missing people, she says.
So what have we? At Wonderwerk, the archaeologists detected 2 million years of occupation and show sporadic fire use from the beginning. If the denizens cooked, they didn't do it a lot, the team members agree. However, Chazan notes that at this stage archaeologists cannot distinguish whether a burned ancient bone was the result of "cooking."
"We have more and more evidence that fire is present – the question is how they were using fire, what is it for and does [its use] intensify at a certain point," he says. "Finding burned animal bones doesn't tell you the full story."
That is sad. On the other hand, it's enjoyable to think that we may owe the very fact that we live in homes to owls and their digestive peculiarities.
