Fish Gave Us the Finger

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.

人的手指由魚類進化而來？

手指非常靈活。你喝帶牛奶的咖啡時候要用它，打鍵盤要用它，甚至提褲子的時候也少不了手指的幫忙。但是你是否曾經(jīng)想過：手指從哪里進化而來？在90年代，科學(xué)家們對個問題進行了許多思考。他們得出的結(jié)論是，手指很可能是從第一批四足動物那里“發(fā)明”出來的。這些科學(xué)家這樣思考的一個理由是因為從一只古代魚的化石骨骼上沒有發(fā)現(xiàn)任何的手指，至少是在這只魚的胸鰭里沒有發(fā)現(xiàn)明顯的手指。但是從魚類進化而來的四足動物卻有手指。

但是現(xiàn)在科學(xué)家們在9月21日的《自然》(Nature) 雜志上報道說上述的觀點有些問題。因為他們發(fā)現(xiàn)了新的證據(jù)，這些證據(jù)表明那只古代魚確實在它的鰭里面存在手指。研究者們對一個3.8億年前的生物標本進行了CT掃描。他們發(fā)現(xiàn)這只魚的不同尋常地保留下來的右鰭的確看起來具有手指一般的骨頭。這些科學(xué)家們認為以前的科學(xué)家們沒有發(fā)現(xiàn)這個的原因在于在以前科學(xué)家使用的樣本中，魚的手指被魚的魚鱗留下的痕跡所掩蓋。所以，看起來魚也有未成型的手指。對這個發(fā)現(xiàn)我們豎起兩個大拇指贊成。

Vocabulary:
Nifty: 靈活
Grab: 抓住
Latte: 帶牛奶的咖啡
Tetrapod: 四足動物
Critter: （口語）動物
Limb: 四肢
Digit: 手指
Pectoral: 胸部的
Fishy: 可疑的
Unearth: 挖掘
Specimen: 樣本
Incipient: 初始的