Backwell says their results have shown without a doubt that at around 44,000 years ago the people at Border Cave were using digging sticks weighted with perforated stones, like those traditionally used by the San.
"They adorned themselves with ostrich egg and marine shell beads, and notched bones for notational purposes. They fashioned fine bone points for use as awls and poisoned arrowheads. One point is decorated with a spiral groove filled with red ochre, which closely parallels similar marks that San make to identify their arrowheads when hunting," says Backwell.
Chemical analysis of residues on a wooden stick decorated with incisions reveals that, like San objects used for the same purpose, it was used to hold and carry a poison containing ricinoleic acid found in castor beans. This represents the earliest evidence for the use of poison.
A lump of beeswax, mixed with the resin of toxic Euphorbia, and possibly egg, was wrapped in vegetal fibres made from the inner bark of a woody plant. "This complex compound used for hafting arrowheads or tools, directly dated to 40,000 years ago, is the oldest known evidence of the use of beeswax," says Backwell.
Warthog tusks were shaped into awls and possibly spear heads. The use of small pieces of stone to arm hunting weapons is confirmed by the discovery of resin residue still adhering to some of the tools, which chemical analysis has identified as a suberin (waxy substance) produced from the sap of Podocarpus (yellowwood) trees.
The study of stone tools discovered in the same archaeological layers as the organic remains, and from older deposits, shows a gradual evolution in stone tool technology. Organic artifacts, unambiguously reminiscent of San material culture, appear relatively abruptly, highlighting an apparent mismatch in rates of cultural change. This finding supports the view that what we perceive today as "modern behaviour" is the result of non-linear trajectories tha
|Contact: Erna van Wyk|
University of the Witwatersrand