The New York Times – Life/Style – In 2015, scientists reported a surprising discovery deep in a cave in South Africa: more than 1,500 fossils of an ancient species of human that had never been seen before.
The creatures are named Homo nalediIt was short, with long arms, curved fingers, and a brain about one-third the size of modern humans. They lived at the time when the first humans roamed Africa.
Now, after years of analyzing surfaces and sediments in the cavern’s elaborate underground, the same team of scientists makes another eye-catching announcement: Homo naledi – despite their small brains – they buried their dead in graves. They lit a fire to light their way through the cave and placed inscriptions on the graves on the walls.
The discovery that hominids with small brains did such hominin things was profound, said Lee Berger, a paleoanthropologist at the University of the Witwatersrand in Johannesburg and leader of the project. This, he said, suggests that big brains are not necessary for sophisticated types of thinking, such as making symbols, cooperating on dangerous expeditions, or even recognizing death.
“This is the moment Star TrekHe said. “You come out, you kind of know, it’s not human, but it’s quite complex. What do you do? This is our moment now.”
The evidence is not enough yet
But many experts on ancient carvings and burials said the evidence still did not support these unusual conclusions about Homo naledi. They said the cave evidence found so far could hold a host of other explanations. The skeletons may simply have been left on the cave floor, for example. The charcoal and inscriptions found in the cave may have been left by modern humans who entered it long after the extinction of Homo naledi.
“The narrative seems to be more important than the facts,” said Maxime Aubert, an archaeologist at Griffith University in Australia.
Berger will describe the findings at a scientific meeting, and the journal will release three papers detailing the evidence eLife. A spokesperson for the journal said the studies are currently under peer review, and those reviews will be published when they are completed.
remains Homo naledi It was discovered in 2013 by two South African cavers exploring the Rising Star Cave. Berger organized an expedition into the complex system of chambers and tunnels, which stretch for miles underground.
“Once you’re in, it’s like you’re on a different planet,” said Tibogo Makhopela, a geologist at the University of Johannesburg who joined the team in 2014.
The researchers found a large amount of the bones, but getting to them required access to some dangerous caves. Some of the lanes were so narrow that only the smaller team members could pass through.
In all, the researchers found the bones of at least 27 individuals. It seemed unlikely to Berger and his colleagues that they had simply been dragged deeper into the cave.
In their 2015 report, the researchers suggested that Homo naledi The bodies were deliberately brought there, but left on the cave floor instead of buried, an act archaeologists call “funerary storage.” This was still a provocative statement, given the primitive appearance of Homo naledi. Berger and his colleagues have argued that the species belongs to a lineage that split off from our ancestors more than 2 million years ago. While our offspring grew up and acquired a large brain, theirs did not.
At first, scientists thought the fossils were evenly spread across the floor of the chamber. But when they dug up more of the sediment in 2018, they noticed two more or less complete skeletons inside the oval depressions.
The skeletons do not appear to have formed the depressions by sinking into the sediment. For example, an orange layer of clay surrounded the oval depressions but was not inside them. Along the edges, the scope looked clean.
This discovery, along with other evidence, led Makhopela and his colleagues to conclude that the remains were buried. “They all seem to show the same thing,” he said.
Until now, only humans were known to bury their dead, and the oldest known human burial dates back 78,000 years. a Homo naledi He lived long before that. Mkhupila said his fossils are at least 240,000 years old and could be as old as 500,000 years.
Scientists also found pieces of charcoal, burnt bones of turtles and rabbits, and soot on cave walls near the excavations. They suggested that Homo naledi Use the glowing embers to light the way to the caves and bring back wood or some other fuel to light the fires. They may have cooked the animals as a meal, or perhaps as a ritual.
When these new discoveries came to light, Berger decided to take a look at one of the chambers, known as Dinaledi, which contained a supposed tomb. He had to lose about 25 kg before he could enter the lane. By July, he was ready for the trip.
Berger went in alone and examined the fossils. On his way out, he passed a pillar. On the side, notice a set of hashtag-like grooves etched into the solid surface.
Getting out was more difficult than getting in. “I almost died,” Berger said, but managed to escape with an injured rotator cuff. Two of the team members, Agustin Fuentes of Princeton University and John Hawkes of the University of Wisconsin, were waiting for him in the next room. Berger showed them pictures of the grooves he had made.
The two scientists immediately went to their phones and brought back the same image: an inscription in a cave in Gibraltar made by Neanderthals. It was strikingly similar to what Berger had just seen.
Fuentes said that based on the increasing number of fossils scientists are finding on the rising star, it looks like Homo naledi They may have visited the cave for hundreds of generations, moving together into the dark depths to bury their dead and mark the place with art.
He argued that this kind of cultural practice would have required some kind of language. “You can’t do it without some complicated connections,” he said.
“I’m very hopeful they’ve buried them, but the jury is out,” said Michael Petraglia, director of the Australian Research Center for Human Evolution. Petraglia wanted to see more detailed analysis of the sediments and other types of evidence before ruling on whether or not the oval depressions were burials. “The problem is that they are ahead of science,” he said.
It could be, said Paul Pettit, an archaeologist at Durham University in England Homo naledi He did not bring the corpses to hide or burial. The corpses could have been dragged there. “I am not convinced that the team has established that this was intentional burial,” he said.
For inscriptions and flames, experts said it was not clear whether Homo naledi He was responsible for them. It could have been the work of modern humans who entered the cave thousands of years later. “It’s all unconvincing, to say the least,” said Joao Zelhao, an archaeologist at the University of Barcelona.
One way to test these possibilities is to collect samples of petroglyphs, coal, and soot to estimate their age.
If human ancestors were like Homo naledi It can take pictures and dig graves, said Dietrich Stout, an Emory University neuroscientist who wasn’t involved in the studies, which means brain size isn’t necessary for complex thinking.
“I think the interesting question going forward is what exactly do big brains need,” said Stout. / Translated by LÍVIA BUELONI GONAALVES
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