South African paleoanthropologist and National Geographic explorer Lee Berger said nine years ago the team found soot-covered walls, charcoal, burnt antelope bones and rocks arranged in a hearth in the Rising Star cave system, where the team uncovered the bones of a new member. human family homo naledi.
The control of fire is considered a crucial milestone in human evolution by providing light for navigating dark places, enabling activity at night, and cooking food, followed by an increase in body mass. However, exactly when the breakthrough occurred has been one of the most debated questions in all of paleoanthropology.
Their discovery is not published in a peer-reviewed journal, but in a press release, and Martin Luther King Jr. Memorial Library in Washington on Thursday. Berger, a professor at the University of the Witwatersrand in Johannesburg, said in an interview with The Washington Post that official documents are under review. “There are a number of big discoveries that will come out in the next month.”
He stressed that his team’s discoveries this summer answer a critical question posed when they announced the first treasure trove of 1,500 fossil bones: How did this ancient species get into a devilishly elusive place, a cave system about 100 to 130 feet below the ground? reach and, in his words, “horribly dangerous”?
The research team now believes that H. naledi used small fires in chambers in the cave system to light its paths. Berger based the claim in part on his personal journey through the narrow passages of the cave, which required him to lose 55 pounds.
Moreover, he argued that the use of fire by a human relative with a brain slightly larger than a large orange upsets the traditional story of our development. For years, experts have portrayed evolution as a “ladder” that is constantly moving upwards towards larger-brained and more intelligent species, while leaving smaller-brained species to extinction.
However, there is growing evidence that the process may be more complex than previously thought; this view would indeed be supported if he had been this small-brained contemporary of the early period. homo sapiens He was advanced enough to use fire.
Berger’s lecture drew criticism, as did some of his earlier claims about H. naledi fossils, rather than using carbon dating and other traditional scientific methods, but accompanied by photographs from the cave.
“There’s a long history of claims that fire was used in caves in South Africa,” said Tim D. White, director of the University of California’s Human Evolution Research Center at Berkeley and a former critic of Berger. “Any claim regarding the existence of a controlled fire would be met with high suspicion if it came through a press release contrary to the data.”
Past reports of humanity’s use of early fire have proven controversial, even when presented with scientific evidence. In 2012, archaeologists using advanced technology reported “conclusive evidence, in the form of burnt bone and ashes of plant remains, that burning events occurred at Wonderwerk Cave around 1 million years ago in South Africa.” Critics have questioned this age estimate, and scientists revised the date to at least 900,000 years after using a sophisticated technique called cosmogenic nuclide dating.
For Berger’s team to prove that they both came from the same period, meticulous studies would need to date both the fire evidence and the H. naledi bones, White said. Other studies should show not only the presence of fire but also its controlled use. The test needs to determine that the material believed to be soot is in fact soot and is not discolored by chemicals or other factors.
Berger acknowledged that one of the biggest challenges he and his colleagues will face will be to date with the materials they find. So far, they said the H. naledi bones date from 230,000 to 330,000 years ago, but Berger stressed that these dates should not be seen as the first or last appearances of the species.
White seemed very skeptical about the absence of stone tools found in the caves. He said archaeologists would expect to find thousands of stone tools at a location that human relatives used to light fires and cook food.
“I will tell you that at this stage there were no stone tools that we found in the presence of a quarry,” Berger said in the interview. “This is a strange thing.” Still, he told listeners in Carnegie Science, “Fires don’t start by themselves within 250 meters of a wet cave, and animals don’t just get into the fires and get burned.”
He said stone tools were found in the general landscape outside the caves. It also repulsed criticism that what the team found was not evidence of an old stove.
“We found not just one hearth, but dozens of hearths,” Berger said when asked about the evidence during the interview. “100 percent. No doubt. … We are now entering a stage where this is just turning from bones into a rich understanding of the environment in which they live.”
Berger had previously been involved in controversy during the initial announcement of the discovery of H. naledi., when he suggested that these ancient relatives deliberately used the caves to lay their dead. Despite the controversy, Berger repeated the claim at several points during the lecture, admitting that it was “perhaps not well received by most of the academy.”
Other researchers said that while there is still a lot of testing to be done, the latest findings in Rising Star are impressive.
“I think it’s great. It looks very believable,” said Richard W. Wrangham, professor of biological anthropology at Harvard University and author of the 2009 book “”.Catching Fire: How Cooking Made Us Human”
“Of course it’s fascinating because of the small and often mysterious nature of these people.”
Wrangham said that when H. naledi’s discovery was announced, Berger had discussed the dark caves where the bones were found with one of his colleagues and said, “This must mean they certainly had light.”
However, Wrangham said he was confused about one thing: “How did they endure the smoke? Was there an air current that was making smoke out of the cave?”
Based on early evidence, Wrangham said he was willing to believe Berger’s word about the use of fire. That said, the strongest evidence for early control of the fire came from an archaeological site in Israel called Gesher Benot Ya’aqov. cook fish about 780,000 years ago.
During the lecture, Berger also shared live descriptions of some of the 50 H. naledi individuals the team found.
He described the fossil bones of a hand “curled into a deadly grip”; the skull of a child sitting on a shelf in the rock; and the skeleton of another child stuck in a recess in one of the rooms. The dramatic displays required an equally dramatic journey through a rift in the dolomite that narrowed to just seven inches and required extreme bending of an explorer’s body.
“You’re basically kissing the ground,” said Keneiloe Molopyane, a 35-year-old researcher at the South African university’s Center for Exploring Deep Human Journeys. “Explorers,” he continued, climbed a dangerous hill about 25 meters above the cave floor. Inside, it’s pitch dark, bats buzzing on both sides. If you fall, you belong in the cave.”
But the reward is something Molopyane vividly remembers from her first descent into the cave system: “Oh my God. I don’t know how many millennia I was the first to see these relics and now I’m touching them.”
About 150 scientists worldwide are involved in efforts to excavate, date and study the remains and artifacts found in the Rising Star cave system, Berger said.
Asked to speculate on possible interactions and possible conflicts between H. naledi and H. sapiens, Berger replied, “Everything you just asked will be answered within the next 36 months.”
