How old is modernity?
Evolution A study has pushed the anitiquity of Stone Age settlements from 20,000 years ago to 44,000 years back. Discoveries at a site in South Africa show that the lifestyle of these ancient people bears a close resemblance to the San people who still live in Southern Africa, writes Ananthanarayanan S .
The earliest Stone Age settlements have been traced to southern Africa, and are said to have existed 20,000 years ago. A group of scientists, including those from the University of Witwatersrand, Johannesburg, have firmly dated evidence of a similar culture that thrived nearly 44,000 years ago. The findings have been reported in the Proceedings of the National Academy of Sciences.
The study is based on analysis of objects, including well preserved organic remains which were found in archaeological layers, at Border Cave, South Africa.Border Cave is a rock shelter in the mountain range that runs across South Africa's border with Swaziland. This cave was discovered in the 1940s and signs of well preserved timeline of human activity are said to be visible here. A detailed study in the 1970s revealed skeletons of animals and humans, apart from thousands of antique articles.
A notable and earliest of these is a piece of baboon bone that bears 29 notches and may have been used as a calendar, in the manner of other ancient communities in southern Africa. The current study, by an international team, has pushed the antiquity further back. "The dating and analysis of archaeological material discovered at Border Cave in South Africa has allowed us to demonstrate that many elements of material culture that characterise the lifestyle of San hunter-gatherers in southern Africa, were part of the culture and technology of the inhabitants of this site 44,000 years ago," says Lucinda Backwell, a senior researcher in palaeoanthropology at Wits University.
Hunter-gatherers
The earliest human communities known so far are said to be ancestors of the hunter-gatherer community, ancestral population clusters that still exist in southern Africa. Hunting and gathering are considered to have been the subsistence mode of humans till 10,000 years ago. Their characteristic feature is the reliance on food from wild plants and free running animals, as distinct from cultivated plants and domesticated or reared animals. The beginning of agriculture put an end to the nomadic lifestyle. It gave rise to settlements and large population. Evidence also suggests that this shift, also called the Neolithic revolution, started in various locations nearly 10,000 - 8,000 years ago.
Remnants of these ancient people are found even today among the hunter-gatherer communities of South Africa. This group in South Africa is identified as the San people. This community does not practise agriculture and bears a resemblance to the Stone Age culture. Women of the community gather wild fruits, berries, tubers, bush onions, and other plant materials for consumption. Also, ostrich eggs are gathered and empty shells are used as water containers.
Many species of insects, including grasshoppers, beetles, caterpillars, moths, butterflies, and termites, form an important part of their diet, especially during the dry season when procuring animal meat is difficult. Hunting is practised with poisoned arrows and spears. These indigenous people have proved to be valuable resources for genetic and anthropological research and their lifestyle has been identified with archeological findings that date from 10,000 to 20,000 years ago.
The significance of the Border Cave discoveries is that it pushes the date of such living practices back to 44,000 years. Examination of stone tools that were found in the same archaeological layers as the organic remains, and from older deposits, reveals the path of evolution in stone tool technology.
Organic artifacts are clearly similar to the material culture of San communities. "This finding supports the view that what we perceive today as modern behaviour is the result of non-linear trajectories that may be better understood when documented at a regional scale," argue researchers from the Wits University.
Vegetable poisons
An interesting part of this discovery is that a wooden stick decorated with incisions, used to hold poison, was used on arrow heads. "They fashioned fine bone points for use as awls and poisoned arrowheads. One point is decorated with a spiral groove filled with red ochre. It closely parallels similar marks that San people make to identify their arrowheads when hunting," says Lucinda Backwell.
The purpose of smearing poison in the arrowheads was to kill tougher animals that could not be easily hunted. The arrow would break, but the head remained and it weakened the prey, over days or weeks. The hunters would follow the prey until it collapsed.
The poison was derived from ricinoleic acid, found in castor seeds. Castor seeds contain ricin, a poisonous protein. The heat used in extracting castor oil denatures and inactivates the protein and castor oil has many uses and commands a good price. But gathering raw castor seeds, during harvest and before processing, is hazardous.
Compounds found on the plant surface can cause permanent nerve damage. In fact, farm workers in India, Brazil and China have been affected by it. Pure, extracted ricin, a protein, is highly toxic and a small dose is enough to kill a human. This poison was found in the arrow heads that were discovered in the Border Cave.
The castor seed poison, along with poisonous plant resin, was mixed with bee wax and wrapped in fibres made from the inner bark of a tree. Backwell says, "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."
Such knowledge of plant based poisons has a link with the tradition of using plant materials for medicinal purposes among the san people. In fact, the San people are one of the first indigenous communities to receive royalties for the use of some of their traditional knowledge by drug companies. Hoodia gordonii, a juicy plant used by the San bushmen to suppress the appetite during long hunting missions, was patented by the South African Council for Scientific and Industrial Research (CSIR) in 1998.
A license was granted to a pharmaceutical concern for development of the active ingredient in the Hoodia plant into a drug for dieting. When the patent came to the attention of the San people, a benefit-sharing agreement was reached between them and the CSIR in 2003. The San were represented by the Working group of Indigenous Minorities in Southern Africa (WIMSA), a regional organisation formed under San leadership.