Earliest evidence of humans eating starchy food found

Modern humans were cooking carbohydrate-rich food as early as 1,70,000 years ago, according to a study which has found the first evidence of this kind from charred remains of plant parts found during excavations in South Africa. The researchers, including those from the University of the Witwatersrand (Wits) in South Africa, said edible root parts from the plant Hypoxis sp. - a genus of small flowering plants - may have been a reliable and transportable staple food for Middle Stone Age humans who lived between 2,80,000-25,000 years ago. According to the scientists, the starchy root may have also been a familiar source of food for early human populations travelling throughout Africa and beyond.

"This discovery is much older than earlier reports for cooking similar plants and it provides a fascinating insight into the behavioural practices of early modern humans in southern Africa. It also implies that they shared food and used wooden sticks to extract plants from the ground," said study co-author Lyn Wadley from Wits. While researchers have been able to re-imagine early human hunting strategies, and animal-based diets based on clues from bones and stone tools they left behind, their plant-based diets have often been difficult to determine due to their perishable nature as evidence in archeological sites.

"It is extraordinary that such fragile plant remains have survived for so long," Christine Sievers, study co-author at Wits, said. The scientists recognised the small, charred cylinders as the root parts, rhizomes. Using a scanning electron microscope, the researchers zoomed in on the food and water transport channels - xylem and phloem, in the rhizomes, and identified the 55 charred remains as those of Hypoxis, commonly called the Yellow Star flower.

"The most likely of the species growing in KwaZulu-Natal today is the slender-leafed Hypoxis angustifolia that is favoured as food. It has small rhizomes with white flesh that is more palatable than the bitter, orange flesh of rhizomes from the better known medicinal Hypoxis species (incorrectly called African Potato)," Sievers said.