Researchers study how early humans thrived through volcanic winter

UTA researcher participates in Nature paper on early human survival
Main Map and profile. Credit: University of Texas at Arlington

UTA researcher Naomi Cleghorn has participated in a Nature paper that describes how humans thrived in South Africa through the Toba volcanic eruption about 74,000 years ago, which created a decades-long volcanic winter.

"We have demonstrated that in two sites along the south coast of South Africa that may have housed the origin population for all modern humans, our ancestors thrived through this volcanic event," Cleghorn, a UTA associate professor of sociology and anthropology, said.

"This may have been the combined result of the uniquely rich resource base of the region and a highly resilient adaptation - a hunting and gathering economy wielded by a modern human with an advanced cognition and high levels of cooperation," she added.

The scientific team found microscopic glass shards that had travelled nearly 9,000 kilometers from the eruption site and landed in the archeological sediments of two sites on the south coast of South Africa. One was a rockshelter at Pinnacle Point where people lived - sleeping at night, cooking food and sharing stories around the campfire. The others were at an open-air site just nine kilometers away, a location where humans collected stone and processed it for future tool manufacture.

"Finding the shards from Toba at these two sites means that we can link the sites at a temporal precision of about two weeks and say that the people at the sites were almost certainly of the same social group, and link activities at one site to the other," Cleghorn said. "For archaeologists, that is an extraordinary result."

Cleghorn began working with the Pinnacle Point archeological project directed by Dr. Curtis Marean of Arizona State University in 2011 and was invited to collaborate on the Toba project in 2012. After working on Pinnacle Point for four years she began research at her current site at Knysna, about 80 kilometers east of Pinnacle Point.

"We know that shortly after Toba, left Africa and conquered the planet," Cleghorn added. "My work at Pinnacle Point and now at Knysna aims to develop a high-resolution chronology of human evolution and social adaptation during that time."

The Toba shards provide a very reliable and precise means to date sites and could help tie together the chronologies of many sites across Southern Africa. Once two sites were identified, the process is extending to other sites, including Knysna, Cleghorn's current dig.

UTA researcher participates in Nature paper on early human survival
Naomi Cleghorn running the total station at the Pinnacle Point 5/6 site. Credit: UTA

UTA's support was instrumental in getting Cleghorn's project started at Knysna. Cleghorn used a Research Enhancement Program grant to run the initial test excavation, which provided the evidence needed to attract external funding for the project over several years from the Leakey Foundation, National Science Foundation, Templeton Foundation and Hyde Family Foundation. The College of Liberal Arts also supported research into mineral pigment use at the Knysna site.

So far, some dozen UTA students have participated in the Knysna field project, and this year Cleghorn is taking five current or former UTA students info the field with significant funding support.

"Naomi Cleghorn's work is foundational to paleosciences and her significant funding also demonstrates the value that leading foundations give to her work," said Elizabeth Cawthon, dean of UTA's College of Liberal Arts. "It is also cross-disciplinary work linking UTA's strategic themes of global environmental impact and sustainable urban communities."


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Humans thrived in South Africa through the Toba super-volcanic eruption about 74,000 years ago

More information: Eugene I. Smith et al, Humans thrived in South Africa through the Toba eruption about 74,000 years ago, Nature (2018). DOI: 10.1038/nature25967
Journal information: Nature

Citation: Researchers study how early humans thrived through volcanic winter (2018, April 25) retrieved 26 June 2019 from https://phys.org/news/2018-04-early-humans-volcanic-winter.html
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Apr 25, 2018
Toba volcanic eruption about 74,000 years ago


sigh . . . 800,000 years ago a meteor impacted southeast Asia creating a crater estimated to be 100 km in diameter.* Denisovan survived. H. Sapiens survived. H. floresiensis survived.

*hint, the world isn't as fragile as the alarmists would have you believe. And no, a tiny volcano like Toba doesn't compare, from a pollution standpoint, to a meteor impact creating a crater 100 km in diameter.

Apr 25, 2018
The most recent, undisputed impact feature with a diameter approaching 100 kilometers is the 35 million year old Popigai crater, which itself may have been responsible for the Eocene extinction event via climate change.

Heck, the only confirmed impact crater on the planet that even approaches your proposed time frame is the 900,000 year old Zhamanshin crater of Kazakhstan, which is not in East Asia and is only 14 kilometers in diameter.

Regardless: The oldest examples of Denisovan people and H. floresiensis date from 100,000 and 700,000 years ago respectively. Even if we assumed your alleged impact was real, neither groups would've been alive yet in the first place.

At any length, there actually isn't any evidence for severe climate change from the Toba eruption itself, courtesy of Lane, Chorn & Johnson's, "Ash from the Toba supereruption in Lake Malawi shows no volcanic winter in East Africa at 75 ka" Proceedings of the National Academy of Sciences 2013.

Apr 25, 2018
@Scolar_Visari quoted a study of volcanic ash in in Lake Malawi to deny climate change caused by the Toba eruption, neglecting to mention that Toba is in the northern hemisphere and Lake Malawi is in the southern hemisphere. The spread of ash and other particulate would vary between hemispheres.

Apr 25, 2018
At no point did I deny climate change from the Toba eruption: I specifically stated there wasn't any evidence for severe climate change. The only reason the Toba eruption is even mentioned at all as a potential climate disaster is because of its coincidental timing with a population bottleneck. The fact that we *don't* find evidence of a volcanic winter circa 75,000 years ago in Africa is quite relevant because the original champions of the Toba catastrophe hypothesis specifically claimed it had severe global effects that also (specifically) impacted the human population in Africa.

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