Photo supplied by Wits University Research department. (professor Sara Wurz)
New discoveries made at the Klasies River Caves (above) in the Humansdorp area of Kouga in South Africa’s eastern Cape, where charred food remains from hearths were found, provide the first archaeological evidence that anatomically modern humans were roasting and eating plant starches, such as those from tubers and rhizomes, as early as 120,000 years ago.
The researchers who found the evidence say these early human beings who lived around 120 000 years ago in South Africa were “ecological geniuses” who were able to exploit their environment intelligently.
The Klasies River Caves are a series of caves located to the east of the Klasies River mouth, south of Tsitsikamma River, in the Humansdorp district of Eastern Cape Province, South Africa. The three main caves and two shelters at the base of a high cliff have revealed evidence of middle stone age-associated human habitation from approximately 125,000 years ago.
Photo supplied by Wits University Research department (professor Sara Wurz)
The new research by an international team of archaeologists, published in the Journal of Human Evolution, provides archaeological evidence that has previously been lacking to support the hypothesis that the duplication of the starch digestion genes is an adaptive response to an increased starch diet.
“This is very exciting. The genetic and biological evidence previously suggested that early humans would have been eating starches, but this research had not been done before,” says Lead author Cynthia Larbey of the Department of Archaeology at the University of Cambridge.
According to Professor Richard Cowling from Cape St Francis in the Eastern Cape Province of South Africa, “This study shows that the earliest inhabitants of our region – indeed, possibly the progenitors of the entire human species – made use of our plants to supplement their diet. They probably relied on the starch from watsonias and other bulbs as a “fall back food”, i.e a source of sustenance when they were unable to harvest shellfish or hunt game. Knowing which plants to use and which to avoid (many are poisonous) must have involved a great deal of plant knowledge. What is important is that this is the earliest evidence anywhere of humans cooking starch foods such as bulbs.”
Photos: (supplied by Professor Richard Cowling of Cape St Francis,) show early diets of Watsonia Aletroides (top) and Pelargonium Triste 9above)
Larbey relates further that at Klasies River a team approach was taken, firstly to find and analyse undisturbed hearths and secondly, to take botanical samples from those hearths and compare findings. “Our results showed that these small ashy hearths were used for cooking food and starchy roots and tubers were clearly part of their diet, from the earliest levels at around 120,000 years ago through to 65,000 years ago,” says Larbey.
“Despite changes in hunting strategies and stone tool technologies, they were still cooking roots and tubers. “This is very exciting. The genetic and biological evidence previously suggested that early humans would have been eating starches, but this research had not been done before.”
Professor Sarah Wurz from the School of Geography, Archaeology and Environmental Studies at the University of the Witwatersrand in Johannesburg, South Africa (Wits University) and principal investigator of the site says the research shows that “early human beings followed a balanced diet and that they were ecological geniuses, able to exploit their environments intelligently for suitable foods and perhaps medicines”.
By combining cooked roots and tubers as a staple with protein and fats from shellfish, fish, small and large fauna, these communities were able to optimally adapt to their environment, indicating great ecological intelligence as early as 120 000 years ago.
“Starch diet isn’t something that happens when we started farming, but rather, is as old as humans themselves,” says Larbey. Farming in Africa only started in the last 10 000 years of human existence.
Humans living in South Africa 120 000 years ago formed and lived in small bands.
“Evidence from Klasies River, where several human skull fragments and two maxillary fragments dating 120 000 years ago occur, show that humans living in that time period looked like modern humans of today. However, they were somewhat more robust,” says Wurz.
Klasies River is a very famous early human occupation site on the Cape coast of South Africa excavated by Wurz, who, along with Susan Mentzer of the Senckenberg Institute and Eberhard Karls Universiteit Tübingen, investigated the small (c. 30cm in diameter) hearths.
The research to look for the plant materials in the hearths was inspired by Prof Hilary Deacon, who passed on the Directorship of the Klasies River site on to Wurz. Deacon has done groundbreaking work at the site and in the 1990’s pointed out that there would be plant material in and around the hearths. However, at the time, the micro methods were not available to test this hypothesis
This research is part of an ongoing investigation into how Middle Stone Age communities interacted with and made use of plants and fire. The investigation dates back to the 1990s, when the archaeologist Hilary Deacon first suggested that these hearths contained charred plants. (At the time, the proper methods to examine the residue were not yet available.) We now know not only that Deacon was right, but also that human beings have always been undaunted in pursuit of their cravings. “Starch diet isn’t something that happens when we started farming,” said Larbey—it’s “as old as humans themselves.”
Permission to reprint the article has been given by Professor Sarah Wurz from the School of Geography, Archaeology and Environmental Studies at the University of the Witwatersrand in Johannesburg.
Edited by Bev Mortimer