Hominids buried dead in caves, theory claims – 06/12/2023 – Science

In 2015, scientists reported a startling discovery deep inside a South African cave: more than 1,500 fossils of an ancient hominid species that had never been seen before.

The creatures, named Homo naledi, were short, with long arms, curved fingers, and a brain about one-third the size of a modern human. They lived at the time when the first humans roamed Africa.

Now, after years of analyzing the surfaces and sediments of the elaborate underground cavern, the same team of scientists is making another important announcement: the Homo naledi —despite their tiny brains—buried their dead in graves. They lit fires to light the way down to the cave and marked the graves with inscriptions on the walls.

Lee Berger, a paleoanthropologist at the University of the Witwatersrand in Johannesburg (South Africa) and leader of the project, said the discovery that a small-brained hominid was doing things similar to humans is profound. It suggests that big brains are not essential for sophisticated kinds of thinking, he said, like making symbols, cooperating in dangerous expeditions or even recognizing death.

“This is the ‘Star Trek’ moment,” he said. “You go out, you know a species, it’s not human, but it’s just as complex for humans. What do you do? This is our moment, now.”

But several experts on ancient inscriptions and cemeteries said the evidence still does not support these extraordinary conclusions about the Homo naledi. The cave evidence found so far could have a number of other explanations, they said. Skeletons may have simply been left on the cave floor, for example. And the charcoal and engravings found may have been left by modern humans who entered long after the extinction of the Homo naledi.

“It seems that the narrative is more important than the facts,” said Maxime Aubert, an archaeologist at Griffith University in Australia.

Berger was scheduled to describe the findings at a scientific meeting on Monday, and three papers detailing the evidence will be released by the journal eLife. The studies are currently under peer review, a spokesperson for the journal said, and those reviews will be published when they are complete.

the remains of Homo naledi were discovered in 2013 by two South African cavers exploring Rising Star Cave. Berger organized an expedition into the complex system of chambers and tunnels, which stretch for miles underground.

“Once you’re there, it’s like you’re on another planet,” said Tebogo Makhubela, a geologist at the University of Johannesburg who joined the team in 2014.

The researchers found a large amount of bones, but reaching them required risky excavations. Some passages were so narrow that only smaller members of the team could get through.

In all, the researchers found bones from at least 27 individuals. It seemed unlikely to Berger and his colleagues that they could have simply entered the depths of the cave.

In their 2015 report, researchers suggested that the Homo naledi moved the bodies there deliberately, but left them on the cave floor instead of burying them, an act archeologists call “deposit”. [ou esconderijo] funerary.” This was still a provocative statement, given the primitive appearance of the Homo naledi. Berger and his colleagues argued that the species belonged to a lineage that split from our own ancestors more than 2 million years ago. While our lineage grew up and gained a big brain, theirs did not.

At first, the scientists thought the fossils were evenly spread across the chamber floor. But as they excavated more sediment in 2018, they observed that two fairly complete skeletons rested within oval depressions.

And it didn’t look like the skeletons had formed the depressions by sinking into the sediment. For example, an orange layer of mud surrounded the depressions but was not inside them. Around the edges, the cut looked clean.

That discovery, as well as other lines of evidence, led Makhubela and his colleagues to conclude that the remains were buried. “Everyone seems to paint the same picture,” he said.

Until now, only humans were known to bury their dead, and the oldest known human burial dates back 78,000 years. O Homo naledi lived long before that. Makhubela said his fossils were at least 240,000 years old and could be as old as 500,000.

Scientists also found pieces of charcoal, burned bones of turtles and rabbits, and soot on the walls of caves near the fossils. They proposed that the Homo naledi he used glowing embers to light the way to the caves and brought back wood or some other fuel to make fires. They may have cooked the animals for food, or perhaps in rituals.

When these new discoveries came to light, Berger decided he should take a look at one of the chambers, known as the Dinaledi, which contained a supposed tomb. He had to lose 24 kilos to get through the pass. By July he was ready for the journey.

Berger went in alone and examined the fossils. On his way out, he passed a pillar. On the side, he noticed a set of grooves similar to “hashtag”, or “tic-tac-toe”, etched into the hard surface.

Getting out was harder than getting in. “I almost died,” said Berger, but he managed to escape with a shoulder injury. Two team members, Agustín Fuentes of Princeton University and John Hawks of the University of Wisconsin, were waiting for him in the adjacent chamber. Berger showed them the pictures of the ruts he had taken.

The two scientists immediately went to their phones and pulled up the same image: an engraving in a cave in Gibraltar made by Neanderthals. It was startlingly similar to what Berger had just seen.

Based on the growing number of fossils scientists are finding in Rising Star, Fuentes said, it looks like the Homo naledi it may have visited the cave for hundreds of generations, moving in droves into the dark depths to bury their dead and mark the spot with art.

This kind of cultural practice, he argued, would have required some kind of language. “You can’t do this without complex communication,” he said.

“I’m very optimistic that they have burials, but the jury is out,” said Michael Petraglia, director of the Australian Research Center for Human Evolution. Petraglia wanted to see a more detailed analysis of the sediment and other types of evidence before judging whether the oval holes were tombs. “The problem is that they are ahead of the science,” he said.

And Paul Pettitt, an archaeologist at the University of Durham in England, said it’s possible that the Homo naledi did not take the bodies to hide or bury them. The bodies may have been washed away by the flood. “I’m not convinced that the team demonstrated that this was a deliberate burial,” he said.

As for the recordings and bonfires, experts said it was unclear whether the Homo naledi was responsible for them. It is possible that they were the work of modern humans who entered the cave thousands of years later. “The whole thing is unconvincing, to say the least,” said Joao Zilhão, an archaeologist at the University of Barcelona.

One way to test these possibilities would be to collect samples of the engravings, charcoal and soot to estimate their age.

If a hominid like the Homo naledi could make recordings and dig up graves, that would mean that brain size is not essential for complex thinking, said Dietrich Stout, a neuroscientist at Emory University who was not involved in the studies.

“I think the interesting question going forward is what exactly are big brains needed for,” Stout said.

^{Translated by Luiz Roberto M. Gonçalves}