您现在的位置: 首页 > 英语听力 > 媒体资讯 > 60秒科学 > 正文

原来青蛙还不会落地就先学会了跳跃(有声)

时间:2010-07-27 15:54:10 来源:scientificamerican 编辑:francie  每天三分钟英语轻松学

| 收藏

评论  打印 字号: | |  

 
Frogs from an ancient lineage reveal that the amphibians developed the ability to jump before they had mastered landing

You’d think an animal that hops would know how to land. But for a kind of frog, that’s not the case. Imagine trying to catch a frog. You reach and they jump, only to land gracefully on their feet a few feet away.

It was thought that all frogs moved this way. They'd push off with their back legs, and then once in flight, rotate the limbs forward. Then they landed fore-limbs first. But researchers compared frogs of the family Leiopelmatidae, which still sport an ancient physiology, to two more modern frog species. Unlike their more graceful cousins, the primitive frogs kept their back legs straight out after they jumped. So they don’t land on their feet. Instead, they do an ungainly belly flop, and then struggle to get to their feet and jump again. The finding is in the journal Naturwissenschaften.

The scientists say that the back-leg push-off must have evolved first, with the ability to rotate and land softly evolving later. Although the bad landers are still around, their more controlled relatives appear to be better at making longer trips, foraging for food and, most importantly, avoiding other animals that have an interest in frog legs—for dinner.

收藏

相关热词搜索: 60秒科学

上一篇:《暮光之城》电影讲解(38):你闻起来真香

下一篇:克拉丽莎节选Expert from Clarissaa

您可能还感兴趣的文章

冰岛火山惊人新发现:火山灰中产生内部电流(有声)
英文文本 Weather balloon data show that the tiny particles within plumes of volcanic ash are constantly generating electrical charge, changing the behavior of

时间:2010-05-28 编辑:

60秒科学:骨头揭示死尸生前重量
听力练习通过骨头形状可大致了解此人生前的重量。--Cynthia Graber报道We see it all the time on shows like Bones and CSI. Skeletal remains can yield all sorts of

时间:2011-03-28 编辑:

60秒科学:高智商儿童未来吸毒几率更高
一项英国的研究发现,儿童时期智商测试得分更高的人,其未来尝试吸毒的几率要高得多.以下由索菲•布什维克报道。

时间:2011-11-30 编辑:

60秒科学:蝴蝶也懂药材 自我治疗伤病
听力练习人类的许多药材资源都来自于植物,而根据种种事例显示,人类并非植物药材的唯一受益物种,许多动物也会寻找特定的植物来治疗自身伤病。Infected monarch butterf

时间:2010-10-19 编辑:

最新文章

无觅相关文章插件,快速提升流量