Fingers are pretty nifty. They let you to grab a latte, type on a keyboard, even pull up your pants. But did you ever wonder: where do fingers come from? In the 1990s, scientists gave this problem a lot of thought. And they concluded that fingers were pretty much invented by the first tetrapods: that is, critters with four limbs. One reason they thought that is because a fossilized skeleton of an ancient fish didn’t appear to have any fingers. Or at least any distinct digits in its pectoral fin. But tetrapods, which evolved from fish, did. Now scientists writing in the September 21st online issue of Nature say that that thinking was…a little fishy. Because they’ve unearthed evidence that suggests that that ancient fish did indeed have fingers in its fins. The researchers did a CT scan on a specimen about 380 million years old. And they found that the fish’s right fin, which was unusually well-preserved, does appear to have digitlike bones. The reason other researchers previously missed them, they think, is because in their samples the fingers were hidden behind marks left by the fish’s scales. So fish, too, seem to have incipient fingers. A finding we give two thumbs up.
我們的手指來自……魚 手指非常靈巧，他們幫你拿咖啡，打字，或是拉褲子。但是你有沒有想過：手指是怎么進(jìn)化來的？上世紀(jì)90年代，科學(xué)家深入思考了這一問題。他們得出結(jié)論：手指基本上是第一個四足動物（有四肢的動物）的發(fā)明。原因之一就是古代魚類的化石骨骼看似沒有手指——至少在胸鰭上沒有明顯的趾結(jié)構(gòu)。但是從魚類進(jìn)化來的四足動物卻有這種結(jié)構(gòu)。 但如今，科學(xué)家在9月21日的《自然》雜志在線版上撰文指出，以前的想法并不正確。這些科學(xué)家發(fā)掘出的化石證明，古代魚類的鰭上的確長有“手指”。他們對3億8千萬年的一個標(biāo)本進(jìn)行了 CT掃描，發(fā)現(xiàn)在保存非常完整的魚右鰭上，確實(shí)有趾形的魚骨。這些科學(xué)家認(rèn)為，以前的科學(xué)家之所以沒有發(fā)現(xiàn)這種魚骨，是因?yàn)樗麄兊臉?biāo)本上的“手指”被魚鱗留下的痕跡掩蓋了。所以，看起來魚兒身上也有手指的雛形。讓我們?yōu)檫@一發(fā)現(xiàn)豎起兩跟大拇指。