New ways with old wheats

Terry Brown & Glynis Jones

Agriculture began about 10,000 years ago in the 'Fertile Crescent', a region of the Middle East comprising the The origins and spread of agricultureplains of Mesopotamia, the deserts of Syria and Palestine, and some of the mountainous areas to the east of Anatolia. Here human communities first began to cultivate crops (wheat and barley were among the first) rather than simply collecting plants from the wild. This was one of the most important events in the human past, as it was the first time that we learnt how to shape the environment to our own ends.

Agriculture had far-reaching effects on human society, spreading across Eurasia and leading to increased populations and eventually to civilisations such as those of classical Greece and Rome. But most of this happened centuries before the invention of writing, so it is only through archaeology that we can try to understand prehistoric agriculture.

Why was farming adopted in the first place? How did it spread? Did the early farmers migrate across Europe, displacing the hunter-gatherers that they found, or was there a more peaceful transfer of the new technology from village to village.

Our project has opened up an exciting new way for studying prehistoric agriculture. We have discovered that it is possible to obtain small traces of DNA from preserved wheat seeds, some dating back to the earliest stages of agriculture. We found that one Bronze Age wheat from Greece contains a gene thought to confer good bread-making quality.

This was surprising because prehistoric wheats are not thought to make good bread. We also found that cultivated wheats are more genetically diverse than previously thought.

This suggests that wheat might have been domesticated twice, in two different places, Emmer wheat grainsrather than just once as archaeologists believed.

An interesting spin-off is that our method can be used to test the purity of modern flour and pasta. Some products described as being made from durum wheat are adulterated with bread wheat, which is cheaper. Our DNA test can distinguish durum from bread wheat.