In the Kalahari Desert of South Africa, has produced a cornucopia of wonders for archaeologists searching for the truth about human origins. Cave art, stone tools, burned bones, soil, and ash, and a collection of crystals have all been found inside the immense 80-foot (25-meter) wide Wonderwerk Cave that runs 460 feet (140 meters) deep into the Earth.
These artifacts and remnants were clearly produced or accumulated in the vastest recesses of prehistory, reaching far back into antiquity.
The entrance to the Wonderwerk Cave, which is now the oldest human “home” known in the world. (Michael Chazan / Quaternary Science Reviews)
But how far back, exactly? According to a new study carried out by a team of archaeologists and geologists from the University of Toronto and Hebrew University in Jerusalem, Wonderwerk Cave was first occupied two million years ago (give or take a couple of hundred thousand years), by a hominin species that lived in southern Africa nearly 2000 millennia before modern humans first appeared in the fossil record.
Assuming their assertion is correct, this would make Wonderwerk Cave the oldest “human” home found anywhere on earth notes Haaretz.
Two of the scientists involved in the latest research, archaeologists Michael Chazen and Liora Kolska Horwitz from the University of Toronto and Hebrew University respectively, have been arguing since 2008 that Wonderwerk Cave was occupied two million years in the past. This hypothesis has been controversial, but sophisticated modern dating techniques have verified the accuracy of their conclusion.
“We can now say with confidence that our human ancestors were making simple Oldowan stone tools inside the Wonderwerk Cave 1.8 million years ago,” exclaimed Ron Shaar, a geologist from Hebrew University and the lead author of a report on this study published in Quaternary Science Reviews. “Wonderwerk is unique among ancient Oldowan sites, a tool-type first found 2.6 million years ago in East Africa, precisely because it is a cave and not an open-air occurrence.”
Delighted to find incontrovertible confirmation of their theories, Chazen and Horwitz refer to the latest findings as “an important step towards understanding the tempo of human evolution across the African continent. With a timescale firmly established for Wonderwerk Cave, we can continue studying the connection between human evolution and climate change, and the evolution of our early human ancestors’ way of life.”
The area of Wonderwerk Cave where 3D scanning was used to examine the evidence. (Zamani Project)
Wonderwerk Cave Dated With New Modern Technology
Dating cave deposits accurately can be extraordinarily difficult. But the Canadian and Israeli scientists found a way to overcome these challenges. Breaking new ground, they applied the principles of magnetic and isotopic analysis to clay and quartz particles removed from a thick sedimentary layer inside Wonderwerk Cave, which also contained stone tools, fire remnants, and animal remains.
In the case of the clay particles, they had been magnetized by their interactions with the earth’s magnetic field before settling inside the cave. And they’d been magnetized in an unusual way, as it turns out.
“Our lab analysis showed that some of the samples were magnetized to the south instead of the north, which is the direction of today’s magnetic field,” Shaar said. “Since the exact timing of these magnetic “reversals” is globally recognized, it gave us clues to the antiquity of the entire sequence of layers in the cave.”
Archaeologists working inside of Wonderwerk Cave. (Michael Chazan / Quaternary Science Reviews)
Paleomagnetic dating worked well with clay, and isotopic dating applied to quartz particles produced additional confirmatory results.
“Quartz particles in sand have a built-in geological clock that starts ticking when they enter a cave,” explained study participant Ari Matmon, the director of Hebrew University’s Institute of Earth Sciences. “In our lab, we are able to measure the concentrations of specific isotopes in those particles and deduce how much time had passed since those grains of sand entered the cave.”
Because the sediment layer analyzed contained actual remnants of human or proto-human activity, it was possible to correlate the dating of the clay and quartz particles with patterns of human occupation at Wonderwerk Cave.
While the dating of “human” occupation of the cave to two million BC was a highly significant discovery, it wasn’t the only enlightening finding to emerge from this sophisticated type of analysis.
Through their study of burned stones, bones, soil, and ash excavated from a spot located 30 meters inside the cave entrance, the scientists discovered that the cave dwellers had been building fires indoors more than one million years ago. As of now, no other cave anywhere in the world has produced evidence of intentional fire-making that dates so far back into the past.
“We don’t have combustion features like at Qesem [cave in Israel],” clarified Michael Chazan. “We’re talking about a burned patch, not a proper constructed hearth.” Chazan speculates that cave occupants may have started blazes by bringing burning pieces of wood harvested from wildfires into the cave, for use under more controlled conditions.
An Oldowan-style stone tool found inside the Wonderwerk Cave. (Michael Chazan / Quaternary Science Reviews)
Who Were the Tool-Making, Fire-Building Wonderwerk People?
Despite the abundance of interesting relics, remnants, and artifacts of hominin activity found inside Wonderwerk Cave, not a single hominin fossil has ever been found there.
It is perhaps not surprising that humanity’s ancestors neglected to bury or deposit deceased individuals in a location where they may have been eating, sleeping, making tools, and producing art. And since Wonderwerk Cave is a ground-level cave that lacks a complex internal architecture, predators and scavengers could have easily entered and removed the remains of anyone whose body had been left inside.
Regardless of the explanation, the lack of fossils either inside or directly outside the cave creates uncertainty as to what species lived there two million years ago.
At that time there were multiple hominin species in existence, and Southern Africa was occupied by at least three such species: two types of Australopithecus, and Homo habilis.
Homo habilis may have been an evolutionary forerunner of modern humans, or simply a variation on a theme that ultimately produced Homo sapiens (the point is disputed among evolutionary scientists). If there were other species around they haven’t been detected in the fossil record, but an absence of evidence isn’t necessary evidence of absence.
Currently, the researchers are strongly inclined to credit the cave’s earliest occupation to Homo habilis, which is known to have manufactured and used Oldowan-style tools in other locations.
“We are placing a sure bet on early Homo, since we are not very adventurous gamblers,” remarked Liora K. Horowitz.
Whoever the original occupants of Wonderwerk Cave were, they helped set a template for cave living that was destined to be followed by other hominin species for countless millennia.