Bread wheat, also called common wheat, makes up 95% of all wheat consumed today. Researchers have now found the oldest known physical evidence of the crop at two Neolithic sites in southern Georgia. The discovery shows that people were cultivating bread wheat as early as the sixth millennium B.C.E., about 8,000 years ago. The study was published in the Proceedings of the National Academy of Sciences.
"It is the first documented evidence of bread wheat," said David Lordkipanidze, general director of the Georgian National Museum. At the time, communities that had lived by hunting and gathering were becoming farmers, a major change in human history. The grains offer direct evidence of that shift.
Earlier genetic studies had suggested that bread wheat emerged about 8,000 years ago through hybridization. Free-threshing wheat crossed with wild goatgrass, producing the wheat now used for much of the world's bread. Scientists believed this happened in the South Caucasus and the area southwest of the Caspian Sea because wild goatgrass originated there. Genetic evidence, however, could only point to a likely origin. It could not provide the same direct proof as ancient grains preserved at a dated settlement. That is why fossilized grains from the two sites are especially important.
The new research provides archaeological support for that idea. Scientists excavated fossilized grains and other plant remains from Gadachrili Gora and Shulaveris Gora, two Neolithic sites in modern-day Georgia. Their findings suggest that the region was one of the centers where bread wheat was first domesticated.
Identifying the grains was not simple. The researchers examined their shape and compared them with modern examples. This allowed them to identify bread wheat as well as hulled barley, lentils, and bitter vetch. But bread wheat can look very similar to durum wheat. To tell them apart, the team studied rachis segments, the small parts of the stem at the head of a wheat plant.
Radiocarbon dating placed the grains at the beginning of the sixth millennium B.C.E. One group dated from 5922 to 5832 B.C.E., while another dated from 5808 to 5747 B.C.E. These dates make the grains the earliest known physical examples of cultivated bread wheat.
The sites also reveal how those early farmers lived. Archaeologists have found circular mudbrick buildings, probably used as houses, along with stone tools and pottery. Some pottery appears to show grapes, people, and serpents. The communities belonged to what researchers call the Shulaveri-Shomutepe culture.
Researchers describe this period as a time of experimentation. Farming was spreading, but people had not yet developed methods such as crop rotation, fertilization, and effective drainage. When the soil became less productive, villagers often moved elsewhere and returned only after the land had recovered.
Together, the grains and village remains show that the South Caucasus was not simply receiving farming practices from other regions. It was also a place where communities tested crops and helped shape an important part of the food system people still depend on today.