Cave debris may be the oldest known example of people eating starch

Small fire pits in a South African cave have yielded what researchers regard as the oldest known examples of a key dish in ancient humans’ daily menu. No, not dessert. Think roasted plant starches.

Charred plant remains found in Klasies River Cave date to as early as around 120,000 years ago, and as late as roughly 65,000 years ago, say archaeologist Cynthia Larbey of the University of Cambridge in England and her colleagues. The organic fragments contain starch granules, but can’t be linked to any known starchy plant species, the team reports in the June Journal of Human Evolution.

Based on plants that would have been locally available, Stone Age people likely cooked tubers and roots in the cave, the scientists say. Compared with raw starchy plants, their cooked counterparts would have provided an especially efficient source of glucose, and thus energy, to people. Human fossils previously found in the coastal cave, located at Africa’s southern tip, also date to around 120,000 years ago.

Ancient starch eating at Klasies River Cave supports the possibility that Homo sapiens evolved genetic upgrades to help with digesting hard-to-break-down starch long before people started farming starchy crops in Africa around 10,000 years ago. Scientists have determined that people today carry more copies of starch-digestion genes than did Stone Age populations, such as Neandertals and Denisovans.

Ancient humans in southern Africa likely ate a mix of cooked roots and tubers, shellfish, fish and game animals (SN: 8/13/11, p. 22), Larbey’s team says. Roots and tubers would have been available year-round. And while little is known about the origins of cooking, campfires were being built at least 300,000 years ago in Africa (SN Online: 2/20/14).