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詼諧的語言，生動(dòng)的內(nèi)容一分鐘快速掌握科技最新動(dòng)態(tài)

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Belly-Flopping Frogs Leapt While Still Bad Landers

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.

你一定認(rèn)為會(huì)跳的動(dòng)物就知道如何著地。但有種青蛙不是這樣。想象一下抓蛙的情形吧，你靠近，它便縱身一躍，緊接著雙腿著地優(yōu)雅地降落在數(shù)英尺開外。

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 sports 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. [Richard Essner et al., Nk4FH]

一般人們認(rèn)為所有的蛙都是這樣：它們后腿蹬地起跳，一旦升空，后肢前擺，前肢后擺，接著前肢先落地。但研究人員對(duì)比了滑跖蟾和兩類現(xiàn)代蛙后發(fā)現(xiàn)情況并非如此?；朋缚迫员Ｓ性忌砹?xí)性，它與兩個(gè)優(yōu)雅的現(xiàn)代近親不同，起跳之后后肢一直是伸直的，降落時(shí)并非腿著地，而是肚子朝下直接撲倒，樣子相當(dāng)難看。之后它會(huì)掙扎著爬起來繼續(xù)跳。這項(xiàng)研究成果發(fā)表在《自然科學(xué)》雜志上。（作者：理查德·艾斯納等，Nk4FH）

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.

科學(xué)家表示，后腿起跳這個(gè)動(dòng)作必然比四肢交替擺動(dòng)、輕盈落地的能力進(jìn)化更早。盡管笨拙的“撲地蛙”依舊生存著，比起那些老練的近親來，它們?cè)谶\(yùn)動(dòng)、捕食領(lǐng)域相形遜色。更重要的是，現(xiàn)代蛙比古蛙更善于躲避獵食者的追捕——尤其是那些喜歡在晚餐來上一只美味蛙腿的獵食者。

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