A scandal erupted between scientists because of the mind of primitive people with a small brain

It was an announcement that shocked the scientific world and made headlines around the world, writes The Observer. Last month, researchers reported that they had discovered burials, carved symbols and tools made by an ancient species of humans with small brains. Finds in the Rising Star cave system in South Africa have shown that members of the Homo naledi species exhibited complex behavior almost a quarter of a million years before modern humans began making graves and making art, even though the brain of this primitive species was not much larger than that of a chimpanzee.

These discoveries were described online in papers yet to be peer-reviewed, but were nonetheless hailed by the authors as an intellectual revolution, a paradigm shift that challenged previous assumptions about human evolution. It has been argued that religion and the arts were in our ancestry long before humans developed large brains.

“Now we are faced with the prospect that a being who lived before the advent of humans was contemplating an afterlife. It completely changes how we should think about human evolution,” said anthropologist Lee Berger, who led Rising Star research.

This statement certainly raised key questions about human nature. If small-brained creatures like Homo naledi (Iced Man, or Dinaledi Man) could already make fire, create art, tools, and graves, then what was the function of all the extra gray matter that modern humans have evolved? This question sparked the prospect of an intriguing scientific debate.

Then the tide changed, says The Observer. Peer reviews of the Homo naledi study have appeared. These documents are “imprudent and incomplete,” it was announced last week. “These claims are inadequate, incomplete and largely based on conjecture rather than evidence,” warned another expert, while a third expert dismissed the documents because they “do not provide conclusive evidence.”

As a result, the team, led by Lee Berger, was at the center of a scientific storm. “I have no objection to the idea that non-Homo sapiens species disposed of their dead, but I expect there will be solid scientific evidence to support such claims before scientists launch massive media campaigns about these ideas,” says paleoanthropologist Andy Harris of La Trobe University in Melbourne, Australia.

This view was echoed by Paige Madison, a researcher at Arizona State University. “To put forward an idea that is so unfounded that it has met with rejection from the scientific community is irresponsible,” she said.

The exaggeration of the intellectual abilities of Homo naledi, shown in a recent Netflix documentary, may detract from exploring the site in the future, added Professor Chris Stringer of the Natural History Museum in London. “Rising Star is such a great site and the naledi stuff is so great that there really was no need to overcook the pudding,” he said. “This will cause trust issues in the future, which may even affect funding for additional work.”

The resting place of Homo naledi was found by amateur speleologists in a chamber littered with bones in the Rising Star Caves near Johannesburg (South Africa) in 2013.

According to The Observer, Lee Berger, then at the University of the Witwatersrand in Johannesburg, organized an expedition that included six female paleoanthropologists slender enough to fit through an 6-inch gap in the rock and into the camera. The remains of several small, human-like specimens have been discovered, which have been named oledi after the local Sesotho word for star, and their remains are estimated to be about 300,000 years old. Homo naledi were about 1.5 meters tall, slender, walked upright, but were adapted to climbing, and had a brain the size of an orange.

However, it was not clear how their remains got deep into the cave system. There was no sign that predators had carried them into the chamber, or that underground streams had taken them there. Thus, Berger’s team concluded that the bones were placed intentionally, and that idea has since been taken to extremes, according to the Netflix documentary Unknown: The Cave of Bones, shown last week and highlighting the Homo naledi team’s research.

Berger and company claim that the bones were not only thrown into the cave, but carefully placed in scraped out depressions and covered with earth. For credibility, a piece of stone in the hand of a Homo naledi child is interpreted as a tool, scratches around the cave are said to be fine art attempts, and darkened patches of soil have been accurately identified as hearths.

However, none of these claims impressed the reviewers of the papers written by Berger and his team. Detractors argue that other interpretations of these results have not been adequately explored. “The hasty publication of such an important unconfirmed finding is likely to lead to dangerous consequences,” said one reviewer.

Lee Berger, whose book Cave of Bones will be published by National Geographic next month, is unrepentant. In an interview with The Observer, he insisted that his team’s recent research was sound and reliable. The exploration of the Rising Cave is not just the work of one or two scientists, there are dozens of researchers behind it. “Their scientific opinions should not be outweighed by two, three or four reviewers. That’s not how it works,” Berger said.

However, not every scientist is convinced by such a position. “Instead of dealing with the issues, the team seems to deny issues with their methods and analysis and attack the motives of the reviewers in an attempt to undermine their criticism,” says Paige Madison.

Nevertheless, Berger remained adamant: “More and more evidence is coming in. We will continue to present more evidence and we will keep these criticisms to ourselves, but I will say to those critics who demand more evidence: we will provide this evidence, so be careful what you wish for.”