For me, it's much more important to document and to share than it be right.
Deep within a South African cave system, the bones of an ancient, small-brained hominin named Homo naledi have prompted a profound question: must the capacity for ritual, symbol, and remembrance of the dead require a large brain? A team of paleoanthropologists now claims that Homo naledi deliberately buried their dead, carried fire into darkness, and carved marks into stone some 240,000 to 500,000 years ago — behaviors long assumed to belong exclusively to cognitively advanced species. The claim remains contested, but the deeper provocation endures: we may have misunderstood what intelligence is, and where it lives.
- A species with a brain one-third the size of ours may have performed burial rituals and created symbolic engravings, threatening to overturn a foundational assumption of human evolution.
- The lead researcher had to lose 55 pounds just to enter the chamber — and on his way out, spotted carved grooves matching Neanderthal engravings found thousands of miles and hundreds of thousands of years away.
- Prominent archaeologists are pushing back hard, arguing the skeletal arrangements could be natural, the charcoal left by later modern humans, and the oval depressions mere geological formations.
- The team chose to publish before completing key dating work, inviting public scientific scrutiny rather than waiting years for certainty — a deliberate, if controversial, act of intellectual openness.
- Three papers are now under peer review at eLife, with reviewer responses to be made public, placing the burden of proof in full view of the global scientific community.
In 2015, more than 1,500 fossils were pulled from the Rising Star cave system in South Africa, revealing a previously unknown species: Homo naledi. Small-bodied, with arms built for climbing and brains roughly a third the size of ours, they walked the African landscape around the same time our own ancestors were beginning to spread across the continent.
Eight years later, the team behind that discovery is making a far more unsettling claim. The fossils, they argue, were not simply deposited by time and geology. Homo naledi appears to have carried their dead into the cave deliberately, laying them in shallow oval depressions dug into the floor. They brought fire into the darkness. And they carved deliberate grooves into the stone — markings that bear a striking resemblance to engravings attributed to Neanderthals in Gibraltar, separated by vast distances and deep time.
Lead researcher Lee Berger, who had to lose 55 pounds to squeeze through the cave's narrow passages and examine the site himself, describes it as a 'Star Trek moment' — the encounter with a mind that is not human, yet capable of something we thought only humans could do. If the evidence holds, it would mean that complex ritual behavior, symbolic thought, and the impulse to honor the dead do not require a large brain.
But the scientific community is not yet persuaded. Critics note that the skeletons in the oval depressions are incomplete and misaligned — not what one would expect from carefully arranged burials. The charcoal and engravings may have been left by modern humans who entered the cave long after Homo naledi vanished. Several leading archaeologists have called the interpretation premature, with one describing it as 'unconvincing, to say the least.'
The team has not yet directly dated the engravings or charcoal — work that could take years. Rather than wait, they chose to publish now and open the findings to public scrutiny, with peer reviews to be posted alongside the papers in eLife. The real question beneath all of this is not simply whether Homo naledi buried their dead. It is whether brain size was ever the true measure of what makes a mind capable of meaning.
In 2015, deep inside a South African cave called Rising Star, scientists pulled more than 1,500 fossils from the rock and sediment. They belonged to a species no one had ever catalogued before: Homo naledi. These creatures were small, with long arms and curved fingers suited for climbing. Their brains were roughly one-third the size of ours. They walked the African landscape around the time our own ancestors were beginning to spread across the continent.
Now, eight years later, the same team is making a claim that has shaken the field. Homo naledi, they say, did not simply die in that cave and get buried by time and geology. The evidence suggests they brought their dead there deliberately. They dug shallow graves—oval depressions in the cave floor—and laid their bodies to rest. They carried fire into the darkness, leaving charcoal and soot on the walls. And they carved marks into the stone, deliberate grooves that look strikingly similar to engravings found elsewhere, made by other ancient species. If true, this rewrites what we thought we knew about the relationship between brain size and the capacity for ritual, for symbol-making, for the kind of thinking we associate with being human.
Lee Berger, the paleoanthropologist who led the expedition, calls it a "Star Trek moment"—the discovery of a species that is not human but possesses a complexity we thought required a much larger brain. The evidence comes from years of careful excavation in the Rising Star cave system, a labyrinth of chambers and tunnels that extends for miles underground. The passageways are so narrow that only smaller team members could squeeze through. When Berger himself wanted to examine the chamber containing the purported graves, he had to lose 55 pounds to fit. He made the journey alone, examined the fossils, and on his way out spotted those grooves carved into a stone pillar. He took photographs. When he showed them to colleagues waiting in an adjoining chamber, they immediately recognized the pattern: it matched engravings made by Neanderthals in Gibraltar, separated by hundreds of thousands of years and thousands of miles.
But the scientific community is not yet convinced. The evidence, critics argue, admits of other explanations. The skeletons might simply have been left on the cave floor and scattered by decomposition and water movement—a practice called funerary caching, which is different from deliberate burial. The charcoal and engravings could have been left by modern humans who entered the cave long after Homo naledi went extinct. The oval depressions might be natural formations, not graves dug by intention. María Martinón-Torres, director of Spain's National Research Center on Human Evolution, points out that the skeletons in the ovals are not complete or fully aligned, which would be expected if they had been carefully positioned in graves. Michael Petraglia, director of the Australian Research Center for Human Evolution, says the team is "ahead of the science"—they have presented a narrative before the evidence has been fully tested. Paul Pettitt, an archaeologist at Durham University, is not convinced the bodies were brought into the cave at all. João Zilhão, from the University of Barcelona, calls the whole thing "unconvincing, to say the least."
The team has not yet dated the engravings, charcoal, or soot directly. That work is on their list, but it could take years given the number of samples. Rather than wait, they decided to publish their findings now and invite the broader scientific community into the conversation. John Hawks, from the University of Wisconsin, explained the choice: "For me, it's much more important to document and to share than it is to be right." Three papers detailing the evidence are being released by the journal eLife, currently under peer review, with those reviews to be posted publicly when complete.
What hangs in the balance is not merely the question of whether Homo naledi buried their dead. It is a fundamental assumption about human evolution itself. Scientists have long believed that large brains conferred major evolutionary advantages—advantages significant enough to justify the enormous metabolic cost of maintaining them and the danger that large infant heads pose to mothers during childbirth. Complex thinking, tool use, symbolic behavior, language—these have been tied to brain size. If a hominin with a brain one-third the size of ours could create engravings and dig graves, then brain size was not essential to these capacities. The question becomes not why we developed large brains, but what exactly large brains are for. That is the real discovery waiting beneath the cave floor.
Citações Notáveis
This is the 'Star Trek' moment. You go out, you meet a species, it's not human, but it's equally complex to humans.— Lee Berger, paleoanthropologist
It seems that the narrative is more important than the facts.— Maxime Aubert, archaeologist at Griffith University
A Conversa do Hearth Outra perspectiva sobre a história
Why does it matter whether Homo naledi buried their dead rather than just leaving bodies in the cave?
Because burial is a ritual. It requires intention, planning, and the ability to imagine that death means something. Leaving a body on the ground is one thing. Digging a hole, placing the body inside, and marking it—that's a statement about meaning.
But couldn't the bones have just ended up in those oval depressions naturally, through decomposition?
That's exactly what the skeptics are saying. The bones could have sunk into soft sediment, or water could have arranged them. The team argues the edges of the depressions are too clean, the surrounding mud layer too distinct. But clean edges can form other ways too.
What about the engravings? Couldn't modern humans have carved those?
Absolutely. That's the hardest part to prove. The grooves Berger found look like Neanderthal engravings, which is striking. But Homo naledi went extinct hundreds of thousands of years before modern humans arrived in Africa. Without dating the marks themselves, you can't be certain who made them.
So why publish now instead of waiting for the dating results?
Hawks said they wanted to document and share rather than wait to be right. It's a choice to invite scrutiny early, to let other minds work on the problem. But it also means the strongest claims are still unproven.
If they're right, what changes?
Everything about what we think brains are for. We've assumed that complex behavior—ritual, symbol-making, cooperation on dangerous tasks—requires a large brain. If Homo naledi did these things with a brain one-third our size, then brain size isn't the limiting factor. Something else is.
What else could it be?
That's the question nobody can answer yet. Language, maybe. Social structure. Time. The ability to pass knowledge between generations. We don't know what Homo naledi had or didn't have.