The first explorers to brave the 7-metre perilous crawl leading to the Chauvet caves in southern France were rewarded with magnificent artwork to rival any modern composition. Stretching a full 3 metres in height, the paintings depict a troupe of majestic horses in deep colours, a pair of boisterous rhinos in the midst of a fight and a herd of prehistoric cows. When faced with such spectacular beauty, who could blame the visiting anthropologists for largely ignoring the modest semicircles, lines and zigzags also marked on the walls? Yet dismissing them has proved to be something of a mistake. The latest research has shown that, far from being doodles, the marks are in fact highly symbolic, forming a written 'code' that was familiar to all of the prehistoric tribes around France and possibly beyond.
     Until now, the accepted view has been that writing appeared to come much later than rock art, with the earliest records of a pictographic writing system dating back to just 5000 years ago. Few researchers, though, had given any serious thought to the relatively small and inconspicuous marks around the cave paintings. Genevieve von Petzinger, then a student at the University of Victoria in British Columbia (Canada), was surprised to find that no one had brought all these records together to compare signs from different caves. And so, under the supervision of April Nowell, also at the University of Victoria, she compiled a comprehensive database of all recorded cave signs from 146 sites in France, covering 25,000 years of prehistory from 35,000 to 10,000 years ago.
     What emerged was startling: 26 signs, all drawn in the same style, appeared again and again at numerous sites. Admittedly, some of the symbols are pretty basic, like straight lines, circles and triangles, but the fact that many of the more complex designs also appeared in several places hinted to von Petzinger and Nowell that they were meaningful - perhaps even the seeds of written communication.
     A closer look confirmed their suspicions. When von Petzinger went back to some of the records of the cave walls, she noticed other, less abstract signs that appeared to represent a single part of a larger figure - like the tusks of a mammoth without an accompanying body. This feature, known as synecdoche, is common in the known pictographic languages. To von Petzinger and Nowell, it demonstrated that our ancestors were indeed considering how to represent ideas symbolically rather than realistically, eventually leading to the abstract symbols that were the basis of the original study. "It was a way of communicating information in a concise way," says Nowell. "For example, the mammoth tusks may have simply represented a mammoth, or a mammoth hunt, or something that has nothing to do with a literal interpretation of mammoths."
     The real clincher came with the observation that certain signs appear repeatedly in pairs. Negative hands and dots tend to be one of the most frequent pairings, for example, especially during a warm climate period known as the Gravettian (28,000 to 22,000 years ago). One site called Les Trois-Frères in the French Pyrenees, even shows four sign types grouped together: negative hands, dots, finger fluting and thumb stencils. Grouping is typically seen in early pictographic languages - the combined symbols representing a new concept - and the researchers suspect that prehistoric Europeans had established a similar system.
     Suspecting that this was just the beginning of what the symbols could tell us about prehistoric culture, von Petzinger and Nowell's next move was to track where and when they emerged. The line turned out to be the most popular, being present at 70 per cent of the sites and appearing across all time periods, from 30,000 to 10,000 years ago. The next most prolific signs were the open angle symbol and the dots, both appearing at 42 per cent of the sites throughout this period.
     Yet while long winters spent in caves might have induced people to spend time painting wonder walls, there are reasons to think the symbols originated much earlier on. One of the most intriguing facts to emerge from von Petzinger's work is that more than three-quarters of the symbols were present in the very earliest sites, from over 30,000 years ago. "This incredible diversity and continuity of use suggests that the symbolic revolution may have occurred before the arrival of the first modern humans in Europe," she said.
     The idea would seem to fit with a few tantalising finds that have emerged from Africa and the Middle East over recent years. At Blombos cave on South Africa's southern Cape, for example, archaeologists have recently discovered pieces of haematite engraved with abstract designs that are at least 75,000 years old. Meanwhile, at the Skhul rock shelter in Israel, there are shell beads considered by some to be personal ornaments and evidence for symbolic behaviour as far back as 100,000 years ago. Does this suggest that these symbols travelled with prehistoric tribes as they migrated from Africa? Von Petzinger and Nowell think so. Iain Davidson, an Australian rock art specialist at the University of New England in New South Wales, on the other hand, is unconvinced that they have a common origin, maintaining that the creative explosion occurred independently in different parts of the globe around 40,000 years ago. Wherever these symbols did emerge, the acceptance of symbolic representation would have been a turning point for these cultures. For one thing, it would have been the first time they could permanently store information.
     One huge question remains, of course: what did the symbols actually mean? With no Rosetta Stone to act as a key for translation, the best we can do is guess at their purpose. Jean Clottes, former director of scientific research at the Chauvet cave, has a hunch that they were much more than everyday jottings, and could have had spiritual significance. With no key to interpret these symbols, though, we can't know whether ancient humans were giving false directions to rival tribes or simply bragging about their hunting prowess. Our ancestor's secrets remain safe - at least for now.

Source: New Scientist (17 February 2010)