SSS 2008-05-07
时间：2019-01-08 作者：英语课 分类：Scientific American(五)月
This is Scientific American's 60-Second Science,I am Steve Mirsky.Got a minute?
It’s accepted that a large meteor impact 65 million years ago was responsible for the mass extinction 1 of the dinosaurs 2. Which opened up niches 3 for birds and mammals. But last week at an evolution conference at The Rockefeller University in New York City, New Zealand biologist David Penny questioned whether the dinosaurs might not have already been on their way out. Penny concentrated on fossils of pterodactyls and birds. Turns out that the average wing spans of pterodactyls had been getting steadily 4 larger before the big impact. By the time the meteor hit, pterodactyls still making a mark in the fossil record had wingspans well over 30 feet. Meanwhile, it looks like the Cretaceous version of shore birds were becoming relatively 5 common, based on fossil findings. So perhaps the smaller pterodactyls had disappeared because the new kid in town, birds, were out-competing them. Penny’s view was certainly not uniformly accepted by other meeting attendees. But it’s an interesting question, whether the meteor might have been not the first strike, but the last straw.
Thanks for the minute,for Scientific American's 60-Second Science,I'm Steve Mirsky.
- The plant is now in danger of extinction.这种植物现在有绝种的危险。
- The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。
- The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
- Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》
- Some larvae extend the galleries to form niches. 许多幼虫将坑道延伸扩大成壁龛。
- In his view differences in adaptation are insufficient to create niches commensurate in number and kind. 按照他的观点，适应的差异不足以在数量上和种类上形成同量的小生境。
- The scope of man's use of natural resources will steadily grow.人类利用自然资源的广度将日益扩大。
- Our educational reform was steadily led onto the correct path.我们的教学改革慢慢上轨道了。
- The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
- The operation was relatively painless.手术相对来说不痛。