托福阅读英语材料：Humans Made Flour 30,000 Years Ago

3万年前，我们的祖先就已经会利用植物的根类淀粉制造面粉了。

We tend to think of cavemen as pretty serious carnivores, hunting game and then roasting the yummy bits over a roaring campfire. But scientists just reported discovering traces of starch on some ancient stone tools. Which suggests that there were probably more than a few bakers in the bunch way back when. The findings appear in the Proceedings of the National Academy of Sciences.

Researchers collected stone tools from three archaeological sites in Italy, Russia and the Czech Republic. Our Paleolithic ancestors called these digs home some 30,000 years ago. The markings on the recovered tools suggest that they were used like grindstones and pestles for processing grains. And they still contained traces of flour.

The flour grains came mostly from cattails and ferns, plants whose roots are rich in starch, kind of like a potato. Processing these plants probably involved peeling, drying and grinding their roots. The resulting flour could then be whisked into a dough and cooked.

The finding pushes back the first known use of flour by some 10,000 years. Which means that 300 centuries ago, Fred and Wilma might have had a kind of prehistoric pita bread on the menu.