科学美国人60秒 SSS 2014-09-19(在线收听) |
66 million years ago, the check shoot the media right, a rock over 60 miles wild, snapped in to the earth. And you know what happened next, the dinos disappeared. But BB says to consider the big picture for a moment.You have to think not only about the animal walking on the planet but also all of resources on which animals are depending. Say for example, dedutation. B has been giving those overshadow impact baken there do. After all, more than half the plants be seen as temperal Northern America, parished along with the dinosaurs. And the type of plants throughout the impact were different as well. B and his colleagues studied thousands of fossil leaves from North T. Spending about millions years both before and after the impact, they measured leaves mass per area. Approxime for how much energy are planning vast its leaves, and the density of veins, which indicates how fast growing the leaf is. Sterty slow growing leaves tend to be evergreens, when as fluency fast growing leaves are harmarch can calmsiduales plants.
Turns out the affect impact that fossil record has more disiduaes looking lit. So just in the fast growing more adaptable seasonal plants beat out the competition after the big heat. The study is here in the journal PLOS Biology.
And it kind of makes I wonder for we haven't overlook to another theory for why are the dinos died out. Maybe they just being careful the test did the situates leaves. |
原文地址:http://www.tingroom.com/lesson/sasss/2014/9/281750.html |