科学美国人60秒 SSS 2014-08-26(在线收听

 Based on the sheer number of ants that invaded my home this summer, it seems hard to believe, but a new study finds that the numbers of invertebrates, which include any animal without a spine, has fallen by nearly half over the past thirty-five years, the same period of time in which the human population has doubled. The estimate appears in the journal Science. 
 
When we think of extinction, we usually picture large charismatic creatures. Like the saber-toothed tiger, the wooly mammoth or even the dodo bird. Over the past five hundred years, more than three hundred species of vertebrates like these have disappeared, but what about creators that fly or crawl under our radar? Butterflies, beetles, spiders, slugs and worms are all in the miss of decline. Much of that die-off is due a habit lost. 
 
In the UK for example, scientists have recorded a thirty to sixty per cent decrease in areas inhabited by common insects, including bees and wasps. While fewer flooding pests may seem a plus, insects also perform functions that are key to human survival, liking pollinating crops and recycling nutrients. So crowding out our invertebrate allies could turn out to a real buzz-kill.
  原文地址:http://www.tingroom.com/lesson/sasss/2014/8/278178.html