SSS 2011-03-15(在线收听) |
This is Scientific American’s 60-Second Science. I’m Cynthia Graber. This will just take a minute. Imagine life without fire. A lot of huddling for warmth. The consensus was that humans could make and control fire when they first migrated north to colder Europe, about a million years ago. But new research says those initial Europeans may not have been fire experts until much later. The study was published in the Proceedings of the National Academy of Sciences. Archaeologists identify ancient open-air encampments through tools, tool production and food remains. To check for evidence of fire, they may look for charred bones and pieces of charcoal. But those artifacts could be from volcanic eruptions or natural fires. Such heated remains would be more clearly linked to humans when found in caves. Two northern European caves in particular show clear evidence of fire. But only relatively recently compared with when humans first showed up. And in the Arago cave in France there’s evidence of fire from settlements younger than 350,000 years, but no such evidence in the older layers. The scientists say these findings show that the use of fire was not controlled for the first 600,000 years after humans arrived in Europe, which made for quite a few long, chilly winters. Thanks for the minute. For Scientific American’s 60-Second Science, I’m Cynthia Graber |
原文地址:http://www.tingroom.com/lesson/sasss/2011/3/143913.html |