An international team of researchers has found numerous fragments of charred starch plant tissues in 120,000-year-old hearths at the archaeological site of Klasies River, the complex of caves and rock shelters located on the Tsitsikamma coast between Port Elizabeth and Plettenberg Bay in South Africa. This new evidence supports the hypothesis that the duplication of the starch digestion genes in early Homo sapiens is an adaptive response to an increased starch diet.
“This is very exciting,” said study lead author Cynthia Larbey, Ph.D. student at the University of Cambridge.
“The genetic and biological evidence previously suggested that early humans would have been eating starches, but this research had not been done before.”
Larbey and colleagues searched for and analyzed undisturbed hearths at the Klasies River site.
“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,” Larbey said.
“Despite changes in hunting strategies and stone tool technologies, they were still cooking roots and tubers.”
“Our research shows that early humans followed a balanced diet and that they were ecological geniuses, able to exploit their environments intelligently for suitable foods and perhaps medicines,” said co-author Dr. Sarah Wurz, from the University of the Witwatersrand in Johannesburg.
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.
“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,” Dr. Wurz said.
Cynthia Larbey et al. 2019. Cooked starchy food in hearths ca. 120 kya and 65 kya (MIS 5e and MIS 4) from Klasies River Cave, South Africa. Journal of Human Evolution 131: 210-227; doi: 10.1016/j.jhevol.2019.03.015