In 1991, Henshilwood, by then an archeologist at the State University of New York at Stoneybrook, returned to Blombos Cave in search of answers. Current theories don’t give the former cave occupants much credit. Homo sapiens may have developed anatomically in Africa 100,000 years or so ago, but only after migrating to Europe about 35,000 years ago did they undergo the “behavioral explosion” that led to modern thought. This was how scientists explained the cave paintings and bone tools of Europe and the lack of such finds in Africa. But Henshilwood and his team soon cast doubt on this view.
Early on they found 28 sharp bone tools–awls to pierce hides or make clothing. What really got attention in archaeology circles, however, were two pieces of red ochre engraved with cross-hatched designs–decorative pieces adorned with what appeared to be a “complex geometric motif,” a sign of advanced thought. “The bone tools and the engraved ochre show the capacity for decoration, ceremony, artwork, conscious forward planning with steps involved–all things that we associate with modern human behavior,” says Dr. Lawrence Tucker, a neurologist at the University of Cape Town.
To establish the age of the objects, Henshilwood analyzed the layers of sand lying above and below them, using a new technique to date individual grains (no dating techniques work on ochre). “If there had been any disturbance of the site, we would have seen a mixture of different grains from different time periods,” said researcher Geoff Duller of the University of Wales. “But we didn’t see that.” After much painstaking work, Henshilwood and his team concluded that the ochre pieces were about 77,000 years old; in other words, they were fashioned more than 40,000 years before Homo sapiens reached Europe. The results were published last week in the journal Science.
Henshilwood says these objects may give scientists a clearer picture of what motivated Homo sapiens to migrate from Africa to Europe. If early humans had the advanced skills needed to catch lots of fish, for instance, perhaps they moved in search of better waters, eventually making their way up the coastline. “We’re looking at an entirely new model for human behavior,” he says.
Some archaeologists are skeptical about that highfalutin claim. “The Neanderthals sometimes scratched on rocks, but that doesn’t mean they were like you and me,” says Richard Klein, a Stanford University anthropologist. They also cite the lack of similar African finds, though neglect may have something to do with it: archaeologists have excavated thousands of Middle Stone Age sites in Europe but only a dozen in Africa. Further research is needed. Whether or not the very first Homo sapiens were capable of abstract reasoning and language is a question that won’t be settled quickly.
