Ancient humans, probably struggling to cope with food shortages, broadened their diets to add grains some 23,000 years ago.
The discovery of plant remains at a site called Ohalo II, in what is now Israel, pushes back the earliest known use of grains some 10,000 years, investigators report in this week’s issue of Proceedings of the National Academy of Sciences.
Stone age hunter-gatherers relied for food primarily on small to medium-sized animals, until increasing population and competition for territory put pressure on the food supply, the researchers report.
The Ohalo II site on the shore of Sea of Galilee provides some 90,000 plant remains, according to the team led by Ehud Weiss of Harvard University.
They found that the principal plant foods used were seeds from small grasses, augmented by acorns, almonds, pistachios, wild olives, raspberry, wild fig and grape.
While small grass grains were a major part of the diet at this point, they were eventually discarded as food, probably because the effort to gather and husk them was so great in comparison to the food value, the researchers suggest.
The major significance of the change in diet, the team reports, is that it eventually led to the domestication of cereal grains such as wild wheat and barley.