London: Hunter-gatherers in ancient Britain may have imported cereals from Europe long before they turned to farming, new research reveals.

Ancient DNA recovered from soil submerged beneath the English Channel suggests that wheat appeared in Britain some 2,000 years before Neolithic farmers began cultivating cereal grains, the scientific journal Nature reported.

The Mesolithic-to-Neolithic transition, when modern humans began to settle and grow food, marks a key step in the evolution of civilisation and technology.

"Mesolithic Britain was not isolated from culturally more advanced mainland Europe as has been argued," said Robin Allaby, anthropologist and plant geneticist at the University of Warwick.

There was apparently some level of interaction, by trade or warfare or both.

"In any case, the people who frequented Bouldnor Cliff (a prehistoric site) must have been aware of products and techniques developed in distant parts of Europe, and they seem to have imported goods and ideas to Britain," Allaby noted.

At Bouldnor Cliff, that lies just off the Isle of Wight and which is submerged under 11 metres of water, scientists have recovered DNA of wheat (Triticum) that matches Near Eastern strains.

The team found no cereal-plant pollen or any other archaeological evidence to suggest that wheat was grown at the site.

"The grain -- or flour, from which the inhabitants of Bouldnor Cliff may have made basic dough -- must have come from a distant place, perhaps from the Balkans or the south of France, which Neolithic farmers had already reached," the authors wrote.

In Europe, agriculture slowly spread from ancient Anatolia (modern-day Turkey), where domesticated plants including wheat were first farmed about 10,000 years ago, through the Mediterranean and central Europe.

Archaeologists believe that farming did not reach the British Isles until about 6,000 years ago.

A possible land connection between Britain and Europe at the end of the last ice age might have made trading easier.

"People on both sides of the English Channel would have been able at the time to traverse the shallow seas with boats," the study argued.