"This is an observation of key progress in human society, as the beginning of baking was likely a major step forward in nutrition," says author Ehud Weiss, a postdoctoral researcher in Harvard University's Department of Anthropology and Peabody Museum. "Our work also provides evidence that ancient people held important knowledge that survives to this day. Ten thousand years before agriculture developed, humans recognized the value of cereals."
Weiss and colleagues from the Smithsonian Institution and University of Haifa found evidence of ancient cereal production at a site called Ohalo II, located in present-day Israel and known from previous research to be 23,000 years old. Situated on the southwestern shore of the Sea of Galilee, this location is covered most years by several meters of water, ensuring an exceptional level of preservation for artifacts entombed within its sediments.
Within the remains of a hut at this site, Weiss and his colleagues found 150 starch granules buried in crevices in a foot-long stone apparently used to grind grains. Comprehensive studies of these starch molecules revealed that more than half were from the family that includes barley and wheat. No starches from roots or tubers were found lodged in the stone, suggesting it was used only as a cereal-processing implement.
Several meters away, the archaeologists found a special alignment of burned stones, similar to hearth-like ovens used by recent and modern nomads and hunter-gatherers. This blackened area was covered with a mixture of ashes and barley grains, suggesting that dough made from grain flour was baked there.
The work by Weiss and colleagues provides some of the first empirical data on old and important problems in Old World archaeology. It sheds light on two issues central to the transition from foraging to food production: when humans began to routinely exploit wild varieties of wheat and barley and when they first developed technologies to pound and grind the hard, fibrous seeds of these and other plants into digestible foodstuffs.
"This work provides fresh evidence that it was hunters and gatherers who first made the technological advances associated with turning grasses and other plants into the productive dietary staples they are today," Weiss says. "Our data indicate that these events took place in southwest Asia, one of the great centers of agricultural origins, by 20,000 years ago -- roughly 10,000 years before either wheat or barley was domesticated."
Weiss' co-authors on the Nature paper are Dolores R. Piperno and Irene Holst of the Smithsonian Institution and Dani Nadel of the University of Haifa. Their work was supported by the Smithsonian Tropical Research Institute, the Andrew W. Mellon Foundation, the American School of Prehistoric Research at Harvard's Peabody Museum, Harvard University, and the American Museum of Natural History.