Using advanced machine learning and climate models, researchers have shown that the ancestors of crops like wheat, barley, and rye probably were much less widespread in the Middle East 12,000 years ago than previously believed. This challenges traditional assumptions about the geography of early plant domestication and agriculture.

In a new study published in the journal Open Quaternary, researchers from the University of Copenhagen and the University of the Basque Country have reconstructed the likely ancient geographic ranges of 65 wild plant species closely associated with early farming in West Asia. These include the wild ancestors of wheat, barley, rye, lentils, and other crops that sparked the agricultural revolution more than 10,000 years ago.

“The first farming societies were established in the Middle East about 12,000 years ago. We know this from the artifacts, seeds, and animal bones that archaeologists have recovered from excavations. But we know little about the natural background vegetation in these areas, which means that we also don’t know exactly where the Neolithic peoples found the plants that they eventually domesticated,” says archaeologist and lead author Joe Roe from the University of Copenhagen.

“Based on our new data, it looks like the ancestors of some of the plants most important to modern agriculture—wheat, rye and barley, etc.—did not grow where we expected and also that they were much less widespread than we thought.”

Roe and his co-author, archaeobotanist Amaia Arranz-Otaegui, were surprised to find that many early crop ancestors appear to have been concentrated in the Mediterranean coast of the Levant, suggesting this area acted as a “refugium” during the rather extreme climate of the late Ice Age.

“This suggests that many wild crops were well adapted to quite cold and dry conditions and did not necessarily expand with the arrival of the warmer and wetter climate in which the first farming communities established themselves,” says Arranz-Otaegui.

Together, these findings provide the clearest picture yet of where the world’s earliest agricultural plants once grew and the kind of landscapes ancient communities lived in when they transitioned from foraging to farming.

[…]