Ruins in the Ethiopian lowlands where ancient humans lived 74,000 years ago
John Kappelman
A campsite in what is now Ethiopia may have been used in the years before, during, and after a massive volcanic eruption 74,000 years ago that changed the Earth’s climate.
The eruption of supervolcano Toba on the Indonesian island of Sumatra was the largest eruption on Earth in the past 2 million years. Some researchers believe it may have caused a volcanic winter that lasted several years and wiped out most humans alive at the time, but the magnitude of that effect is debated .
Bones found at Ethiopian ruins suggest people living there had to adapt their diet to survive the dry year or two after the eruption, but the effects were mild It seems like it was.
“It was a pretty lucky discovery,” he says. John Kappelman A team from the University of Texas at Austin discovered the site in 2002. “There’s no question about that.”
Most of the remains of early humans are caves that were inhabited for tens of thousands of years, he says. However, this camp is an outdoor location near the Simfa River, a tributary of the Blue Nile. “Our intuition is that this place has probably been occupied for about five to 10 years,” Kappelman said.
The researchers found thousands of stone fragments from the tool’s manufacture, along with several stone tips believed to be among the oldest arrowheads ever discovered. “We have evidence of archery in the form of these small stone points,” Kappelman says.
Researchers also found ostrich eggshells and numerous animal bones, some with cuts and signs of cooking. Therefore, it is believed that people brought animals back to the site for slaughter and cooking.
The researchers also found volcanic ash in the form of tiny glass shards, known as cryptephra, in the middle of layers of sediment containing stone chips and bones. “They’re just tiny little glass shards,” Kappelman says – and their composition matches other debris from the Toba supereruption.
Isotopic analysis of ostrich shells suggests that the climate became drier after the eruption. This is consistent with a four-fold increase in the amount of fish carcasses identified and a decrease in other types of animal carcasses.
The research team explains that the Shinfa River is seasonal, and during the dry season it dries up to create a water hole. Immediately after the Toba eruption, the dry season was long, making it easier to catch fish in the narrowed water holes. The researchers suggest that this compensated for the decline in terrestrial predators.
Over the next few years, food debris returned to pre-eruption levels and there were no signs of mass mortality, Kappelman said.
Other researchers argue that early humans moved to wetter areas as conditions dried, he says. For this reason, it is also believed that the migration of people from Africa took place during times when the climate was wetter, allowing them to survive in the usually arid region between Africa and Eurasia.
“Our remains show that humans adapted to seasonally dry conditions,” Kappelmann says. He thinks this means that the migration of modern humans from Africa, which may have occurred as recently as 65,000 or 60,000 years ago, may have occurred during a dry period.
However, Kappelman agrees that early migration from Africa by less sophisticated peoples may have been limited to wet periods.
“This is an interesting paper for many reasons: the likely precise link to the Toba supereruption, environmental evidence, survival behaviors including fishing, the possible use of bows and arrows, and the possibility that it facilitated dispersal from Africa. “A certain behavioral adaptation,” says chris stringer At the Natural History Museum in London.
“While each of these proposals will certainly stimulate debate, I think the authors have presented a plausible, if not conclusive, case for each scenario they propose,” he says.
The study also adds to the evidence that the global effects of the Toba supereruption were relatively small and short-lived, Stringer said.
but stanley ambrose One researcher at the University of Illinois at Urbana-Champaign believes that Toba wiped out most humans, but he disagrees. He said the site may represent a much longer period of time than Kappelman’s team thinks, meaning the impact on people could have been much greater. There is.
“Material deposited by humans long before and long after the eruption, perhaps centuries to more than a thousand years ago, was deposited by well-known disturbance processes such as rodent burrowing and cracks forming during desiccation. It could have been juxtaposed with a volcanic ash layer, season,” Ambrose says.
Source: www.newscientist.com
