Stone Age man wasn't so dumb
Archaeologists are rethinking our cultural origins in the light of new discoveries in South Africa. Andrew Luck-Baker reports
IN a cramped cave that looks out across the swell of the Indian Ocean,
South African archaeologists are unearthing evidence of Middle Stone Age
people well ahead of their time. The prehistoric occupants were painting
their bodies red for rituals and carving abstract symbols. They were fishing
and using bone awls, perhaps for leather working.
This is a South African team's interpretation of life in Blombos Cave some time between 80,000 and 100,000 years ago. If correct, many prehistorians will be inclined to change their views about the origins of modern human culture and mind. Our ancestors should not have been doing these sophisticated things for another 40,000 years at least.
The cave is high in a limestone cliff on a wild stretch of the Southern Cape coast of South Africa. The first hints of something extraordinary came in 1993 with the discovery, by Dr Chris Henshilwood of the South African Museum, of stone artefacts known as bifacial points. They look like spear tips and some are symmetrical, shaped like leaves. Their most remarkable aspect is that they've been made in a style that has only been seen before in Europe, dated at 19,000 years old.
Further excavations highlighted the Blombos people's sophistication - implements of ground and polished animal bone. At 80,000 to 100,000 years old, these are among the oldest bone tools in Africa, and much older than shaped tools discovered elsewhere. Although our ancestors worked stone 2.5 million years ago, they learnt relatively late that bone could be fashioned into something useful. But, as with stone technology, it looks as though the idea started in sub-Saharan Africa.
Fishing is another activity humans invented late in prehistory, and Blombos has the earliest evidence for that, too. Dr Judy Sealy of the University of Cape Town says the Middle Stone Age cave floor layers contain fish bones. Fishing is thought to be a much later innovation, so the question at Blombos is whether these fish were caught, or scavenged. If people picked up dead fish from the shore, different species should be represented. The fish in the cave have been identified by Cedric Poggenpoel as the remains of only a few species, so are likely to have been caught.
At Blombos, we have African hunter-gatherers at 80,000 years ago doing many things associated with the Late Stone Age "cultural explosion" 40,000 to 30,000 years ago - when Homo sapiens arrived in Europe for the first time. In fact, the notion of a recent origin of cultural modernity has been under attack anyway. American researchers have found barbed bone harpoons and catfish remains at another, albeit controversial, site dated 80,000 to 100,000 years old in the Democratic Republic of Congo. There are other sites in Africa of similar age with some elements of the Blombos cultural package.
Further afield, it looks as though Homo sapiens was smart enough to travel by sea from Indonesia to Australia about 60,000 years ago. The fossil remains, and genetic analyses of living people, point to an origin for our species somewhere in sub-Saharan Africa about 150,000 years ago, and the first dispersals of Homo sapiens out of Africa perhaps 50,000 years later. However, the archaeological record in the near East indicates that the earliest migrants weren't behaving any more fancily than the Neanderthal people who had already been in the Levant and Europe for about 200,000 years. Consequently, there is much debate about when and where anatomically modern bodies started acting and thinking in modern ways.
For archaeologists, symbolic behaviour - manifest in art and body decoration - is the great hallmark of modern behaviour and mind. Some even argue that the appearance of symbolism correlates with the origin of syntactical language in our ancestors. The most obvious examples of symbolism are the carved figurines and cave paintings of Upper Palaeolithic Europe (African Later Stone Age). But there is evidence of symbolic behaviour much earlier at Blombos. Ochre, and lots of it.
Ochre is natural red iron oxide, and is used by hunter-gatherers today as a pigment for body paint. Dr Henshilwood believes the occupants of the Blombos cave used it for the same purpose. The ochre here is not the oldest on record. Small amounts show up at African sites as old as 300,000 years, but its occurrence is sporadic until about 120,000 years ago. Thereafter, in southern Africa, it appears more regularly and seems to have played a more important role in Stone Age life.
At Blombos, the archaeologists have found hundreds of lumps, as well as powder traces on stone and bone tools. Many pieces have been ground and worked. "The most intensively ground pieces take the form of crayons," says Ian Watts, a British archaeologist studying Blombos ochre. "Some are beautiful and the implication of such honed points is that they were used for design."
There is even one piece with a carved cross-hatched design - three straight lines with another set of three at a diagonal to them. "This," says Dr Henshilwood, "is undoubtedly a symbolic act - the earliest evidence in the world for that kind of symbolism." It reinforces the South African team's belief that the ochre was for symbolic body decoration. Dr Henshilwood imagines the Middle Stone Agers would have ground powder from the raw chunks and then mixed it with animal fat. They would have smeared the bright red mixture on their bodies for rituals.
Explanations for why our ancestors took to painting their bodies are speculative. Dr Geoffrey Miller, an evolutionary psychologist at University College, London, and author of a forthcoming book, The Mating Mind, believes the custom began as a way of attracting sexual partners. "In many traditional societies today," he says, "people only start to paint their bodies once they've reached adolescence." The practice tails off once they have passed the peak of their sexual lives and settled down to family life.
Dr Miller believes it makes evolutionary sense to pick the best body decorator. As well as choosing someone who looks good, you're also selecting valuable genetic endowments for any children you have; genes for assets such as dexterity, creativity, conscientiousness and resourcefulness, because ochre can be hard to find. These are traits for survival as well as for artistry.
A competing hypothesis gives women the credit for inventing body painting. It proposes they did so as a method of birth control about 300,000 years ago, when ochre first appears in the archaeological record. At this time, the brain size of our ancestors was rising steeply towards modern levels and there was a prolonged period of childhood dependency.
Modern human babies take much longer than other infant species to develop to the point when they can look after themselves. As brains became large, it would have been advantageous for a mother to have some means of limiting the number of dependant children on her hands at any one time. That would bolster the survival chances of her family and, therefore, her genes. Camilla Power of University College London proposed that related women smeared themselves with red ochre to mimic menstrual blood and make it difficult for men to distinguish cycling from non-cycling females.
An extra zap of girl power is added to this hypothesis at 100,000-120,000 years ago, according to Ian Watts, when ochre use was more frequent and widespread in southern Africa. At this time, all the women in a group painted themselves red for regular sex strikes: the message to the men being not to hang around, expecting sex, but to go and do something useful such as hunting, fishing or collecting ochre.
Maintained by Francis F. Steen, Communication Studies, University of California Los Angeles