Shell beads newly unearthed from four sites in Morocco confirm early humans were consistently wearing and potentially trading symbolic jewellery as early as 80,000 years ago. These beads add significantly to similar finds dating back as far as 110,000 in Algeria, Morocco, Israel and South Africa, confirming these as the oldest form of personal ornaments.
     A team of researchers recovered 25 marine shell beads dating back to around 70,000 to 85,000 years ago from sites in Morocco. The shells have man-made holes through the centre and some show signs of pigment and prolonged wear, suggesting they were worn as jewellery. Across all the locations shells were found from a similar time period from the Nassarius genus. That these shells were used similarly across so many sites suggests this was a cultural phenomenon, a shared tradition passed along through cultures over thousands of years. Several of the locations where shells have been found are so far inland that the shells must have been intentionally brought there.
     "We found evidence they had been strung together as in a necklace or bracelet,' said Professor Nick Barton of the University of Oxford, one of the authors of the study. The shells had been deliberately perforated using stone tools and the researchers found distinctive wear patterns which suggested they had been rubbing together. Wear marks around the perforations indicated the shells had been threaded on a string. Several had also been covered with a pigment called red ochre and one shell showed evidence of heating, possibly to alter its colour.
     "Either people went to sea and collected them, or more likely marine shell beads helped create and maintain exchange networks between coastal and inland peoples. This shows well-structured human culture that attributed meaning to these things," said Francesco d'Errico, lead author and director of research at the French National Centre for Scientific Research (CNRS). For scientists, beadworks are not simply decoration, they also represents a specific technology that conveys information through a shared coded language. "The early invention of the personal ornament is one of the most fascinating cultural experiments in human history," d'Errico continued. "The common element among such ornaments is that they transmit meaning to others. They convey an image of you that is not just your biological self."
     Until recently the invention of personal ornaments was thought to coincide with the colonisation of Europe some 40,000 years ago, linking advanced cognitive capacity to early human dispersal. Yet this changed with the 2006 discovery of shell beads in Africa and the Near East dating back 35,000 years earlier, showing that symbolic thinking emerged more gradually through human evolution. Curiously, shell beads disappear from the archaeological record in Africa and the Near East 70,000 years ago, along with other cultural innovations such as engravings on ochre slabs, and refined bone tools and projectile points. They reappear in different forms up to 30,000 years later, with personal ornaments simultaneously re-emerging in Africa and the Near East, and for the first time in Europe and Asia.
     The researchers suggest the gap was due to climate change. As the world slid into another ice age the warm, humid North African climate dried out. As a result, human populations shrank, and cultural innovations such as shell beads may have been lost. Only with the expansion of the human population 20,000 years later were these cultural ideas rediscovered.

Sources: Planet Earth Online (25 August 2009), EurekAlert! (27 August 2009)