Farming's great minds thought alike

日期:2017-10-11 03:33:34 作者:娄情倦 阅读:

WHEAT was domesticated more than once, says a molecular biologist who is analysing ancient and modern crops. His discovery supports the idea that agriculture wasn’t a one-off innovation but occurred in many places at once as the climate changed at the end of the last ice age. Terry Brown of the University of Manchester Institute of Science and Technology has extracted tiny amounts of DNA from grains of 3000-year-old wheat found in Greece and Italy. By comparing this DNA with samples from modern varieties, he hopes to trace the origins of crops and their spread through Western Europe. Already, Brown’s studies of modern wheat have shown that it has two distinct genetic lineages, suggesting that subtly different wild plants were domesticated on at least two occasions. Brown believes wheat began to be farmed at about the same time across a wide area of the Middle East, rather than starting in one area and spreading from there. Archaeologists believe that wheat was domesticated 10 000 years ago as part of a series of cultural changes called the Neolithic Revolution, which occurred as the climate became wetter and lusher. “This might have made it easier for people to grow wheats rather than forage for them,” says Brown. The present distribution of the two wheat lineages suggests that one strain may have followed the other into Western Europe, each taken by a different group of farmers. Working with palaeobotanist Glynis Jones of the University of Sheffield, Brown is trying to date the spread of these lineages by examining wheat grains from archaeological sites. Eventually,