Cave's ancient treasure
77,000-year-old artifacts could mean human culture began in Africa
In an African cave high above the rocky shores of the Indian Ocean, a group of anatomically modern humans left a legacy of finely wrought artifacts some 77,000 years ago that could place the origins of human culture many thousands of years before they emerged in Europe.
The artifacts include a trove of unusually sophisticated tools of stone and carved bone. Most dramatic are two small pieces of soft red stone on whose surface someone had inscribed crisscrossed triangles and horizonal lines believed to have symbolic meaning.
The patterns, say archaeologists who are reporting on the relics today in the journal Science, show that the capacity for creative and symbolic thinking must have come to humanity at least 35,000 years earlier than previously believed.
Anthropologists have long thought that the "creative explosion" of human culture began in the late Stone Age, with the Cro Magnon people of Europe, some 40,000 years ago. That era saw the emergence of bone tools, early statuary, beads and the extraordinary cave paintings of France's Lascaux and Chauvet and Spain's Alta Mira.
The new findings, the archaeologists say, indicate that human culture first emerged not in Europe, but in Africa, where anatomically modern humans are believed to have emerged some 130,000 years ago. The conclusion is bound to reopen debate about the origin and evolution of modern human behavior.
In a series of recent scientific articles, including today's in Science, an international team of scientists has described a hoard of unique artifacts discovered in South Africa's Blombos Cave, less than 200 miles from Cape Town.
The team's leader is Christopher Henshilwood, an archaeologist at Cape Town's South African Museum and an adjunct professor of anthropology at the State University of New York in Stony Brook. He has been exploring the Blombos Cave for more than 10 years with colleagues from America, Norway, France and Britain.
"We're pushing back the date of symbolic thinking in modern humans -- far, far back," Henshilwood said in a telephone interview from his office in Cape Town this week.
"It must change dramatically the model of cultural evolution that insists that symbolic thinking only evolved in Europe from 35,000 to 40,000 years ago, " he said. "The engraved designs on the ocher stones are the cherry on the top of our evidence. There's a system in the patterns, and though we may not know what they mean, they are obviously symbolic."
Ocher is a highly oxidized iron ore that appears in colors ranging from yellow to brown to red. In the Blombos cave next to a series of well-formed hearths, the research team discovered a flat piece of ocher about 2 inches long and 1.7 inches wide and another that is 4.6 inches long and 3 inches wide.
Both have intricate inscriptions -- one with a single horizontal line drawn through a complex design of triangles and crosses; the other with three lines drawn horizontally through a similar design.
On the backs of both, plus many of the 8,000 other ocher chunks found in the cave, are long groves from scraping -- probably to obtain red ocher powder for tanning hides, body painting or other symbolic decoration that has long since disappeared, Henshilwood said.
Also found were intricately flaked stone spear points and bone tools inscribed with waving lines, indicating a sophisticated use of awls for working soft materials. Carefully dated fish bones found in the cave show that the people were using advanced techniques for catching fish.
The dating methods used by Henshilwood's team are not under serious challenge, but the group's conclusions are.
One of the challengers is Richard G. Klein, a Stanford anthropologist who has worked with Henshilwood. Klein is on the scientific executive committee of the Leakey Foundation in San Francisco, which has helped finance the Blombos Cave project along with the National Science Foundation and the National Geographic Society.
"I think Chris' work is interesting," Klein said in an interview. "I'm intrigued, but it's still a unique find, and there are at least 30 other sites in the region that don't show anything like this one, so such a unique find cannot force us to revise our ideas of when and where modern symbolic thinking began."
In fact, Klein said, the markings on Henshilwood's prized ocher stones may not be deliberate designs at all, but merely "doodling."
Klein and other anthropologists have speculated that the "creative explosion" in human culture may have come about through an abrupt genetic change that altered the brain circuitry of European humans about 50,000 years ago and enabled them to think symbolically and creatively.
That explanation is controversial, but it could explain why, 35,000 to 40, 000 years ago, sophisticated cultures spread quickly in Europe, where gene changes could propagate rapidly through populations that were more dense than in the isolated sites of stone age peoples.
Sally McBrearty, an archaeologist and fossil expert at the University of Connecticut, argues that there is no evidence for genetic mutations encouraging symbolic thinking.
Her own research at sites in Kenya, she said in an interview, indicates that "even those early people more than 100,000 years ago showed symbolic behavior, cognition and as much intelligence as modern people." Henshilwood's evidence, she said, "is very convincing -- it's the real deal."
There is other tentative evidence for the emergence of complex symbolic thinking in Africa, according to John E. Yellen, an archaeologist at the National Science Foundation who has excavated a 90,000-year-old site in the Katanda region of Zaire.
Working at Katanda more than a decade ago with his wife, Alison S. Brooks of George Washington University, the two discovered bone points with barbs on three edges and rings carved at their bases to tie them to shafts -- evidence, he said, of sophisticated spears for organized fishing expeditions with giant fish as their prey.
The evidence, Yellen and Brooks said, indicates that the ancient people "not only possessed considerable technological capabilities at this time, but also incorporated symbolic or stylistic content into their projectile forms."