SSS 2012-08-09(在线收听

 This is scientific American sixty seconds science, I'm Cynthia Graber, this will just take you a minute.

 
Tea and coffee are drunk worldwide, far beyond their original ecological niches. Now it looks like another caffeinated beverage also gained popularity far from its home.
 
Archaeologists call it Black Drink—a caffeinated brew of toasted leaves and twigs of the holly plant. It was imbibed, often ceremonially, in many regions of the Americas. Researchers say they’ve found the earliest trace of Black Drink—in a region that doesn’t grow holly.
 
They investigated Cahokia, a large pre-Columbian political body. It encompassed floodplains and hills near today’s Saint Louis. It’s tough to find plant matter, so scientists searched for traces of theobromine, caffeine and ursolic acid in ceramics in the right proportion—a sort of chemical signature for holly. And they were able to date Black Drink back to about the year 1050, almost a thousand years ago. But the nearest holly grows hundreds of miles away.
 
The findings are in the Proceedings of the National Academy of Sciences. The researchers say this is the earliest evidence of Black Drink consumption. And that Black Drink was traded for ritual consumption far from where it was grown. Much like our morning cup of joe.
 
Thanks for the minute for scientific American sixty seconds science. I'm Cynthia Graber.
  原文地址:http://www.tingroom.com/lesson/sasss/2012/8/199314.html