Web edition: July 31, 2012
Print edition: August 25, 2012; Vol.182 #4 (p. 16)
People living in a South African cave 44,000 years ago crafted the same kinds of blades, beads and tools as hunter-gatherers of the region today. The artifacts push the history of modern human behavior in southern Africa back more than 20,000 years, archaeologists report online July 30 in the Proceedings of the National Academy of Sciences, forging a link between the cultures of ancient and present-day humans.
“We’re not just looking at people who were modern. We’re looking at people who were modern in a way that we know,” says study coauthor Francesco d’Errico of the University of Bourdeaux in Talence, France.
Many of the artifacts from South Africa’s Border Cave represent tools and technologies identical to those used by the San hunter-gatherers of southern Africa today.
Using radiocarbon dating, researchers pinpointed the ages of wooden digging sticks, ostrich shell beads, bone awls and stone flakes that may have been part of a sophisticated hunter-gatherer tool kit cum jewelry box.
The collection is characteristic of the Later Stone Age, a time period many archaeologists believed began in southern Africa about 20,000 years ago. But the new radiocarbon dates show the Later Stone Age actually emerged between 44,000 and 42,000 years ago, says study author Paola Villa of the University of Colorado Museum of Natural History in Boulder. The new dating aligns South Africa’s Later Stone Age with Europe’s Upper Paleolithic — a time also known for cultural and technological innovations.Archaeologists have previously dug up hunter-gatherer artifacts in southern Africa that date back as far as 75,000 years ago. But the artifacts’ link to present-day people is unclear; they may be leftovers from cultural experiments that didn’t stick, d’Errico says. Scientists can link more recent artifacts — from 20,000 years ago — to today’s hunter-gatherers, but gaps in the archaeological record between the two time periods present “one of the enigmas of southern African archaeology,” says Christopher Henshilwood, an archaeologist at the University of the Witwatersrand in Johannesburg. The new findings help close the gap, he says. “It gives us a much better view of what happened during this time period.”
D’Errico and colleagues spotted microscopic smudges of dark orange residue at the tip of a thin wooden stick. In another artifact — a lump of mysterious material — they saw fiber-filled grooves. Chemical analysis revealed the orange residue was likely poison made from castor beans; the lump was beeswax wrapped in twine and laced with poison.
The beeswax had the utility of a Swiss army knife, d’Errico says. Stone Age MacGyvers could use the wax to stick poison to an arrow’s bone tip, or to carry extra twine for hafting arrowheads to shafts. The handy tool dates to 40,000 years ago, and is the oldest evidence for the use of beeswax.The complex hunter-gatherer tool kit also included flakes of stone “about the size of your fingernail,” says Villa. Her team sorted through thousands of stones from the cave’s sedimentary layers, and analyzed bits of brown residue that still clung to some of the flakes. The residue — sticky pitch made from tree bark — glued handles to stones, says Villa. The small stones, or microliths, were buried in the same layer as the beeswax, marking a gradual shift away from the types of tools used in earlier times.
F. d’Errico. Early evidence of San material culture represented by organic artifacts from Border Cave, South Africa. Proceedings of the National Academy of Sciences. Published online July 30, 2012. doi:10.1073/pnas.1204213109. [Go to]
P. Villa. Border Cave and the beginning of the Later Stone Age in South Africa. Proceedings of the National Academy of Sciences. Published online July 30, 2012. doi:10.1073/pnas.1202629109. [Go to]
B. Bower. Deep African roots for toolmaking method. Science News. Vol.178, November 20th, 2010, p. 5.