How agriculture ground to a start.

Scientists would love to know how western Asians made the revolutionary shift from seed scrounging to cereal cultivation around 11,000 years ago. Some researchers speculate that the shift occurred after people began using sickles to cut down barley and other wild grasses. Others argue that cultivation emerged from practices such as uprooting plants, hand-plucking grains, or shaking grains off wild cereal stalks into baskets.

In an upcoming Proceedings of the National Academy of Sciences, Mordechai E. Kislev of Bar-Ilan University in Ramat-Gan, Israel, and his coworkers suggest another scenario. The inventors of agriculture in western Asia probably walked through patches of wild barley and wheat during summer months and scooped handfuls of ripened grains off the ground. This practice would have provided surplus grains for sowing elsewhere, a major advance in farming, according to the researchers. It would also have fostered the observation that fallen seeds yield new plants in late autumn, they add.

This account comes from modern first-hand experience. In dense patches of wild barley and wild wheat located in three Israeli regions, Kislev's team observed thick carpets of ripened grains that had fallen and were easy to collect from May to October. Analyses of cereal grains found at Israeli sites occupied by people around 11,000 years ago indicate that most were ripe and were probably collected off the ground, the researchers assert.--B.B.