評論
打印
Science and technology
科學技術
Why zebra are striped
為啥斑馬身上是條紋
Horse sense
馬識
Are zebra stripes just an elaborateinsect repellent?
斑馬身上的斑紋只是精致的驅蟲器嗎？
Imagine what it looks like to a fly
想象一下這在蠅的眼里是幅什么樣的畫面
HOW the zebra got his stripes sounds like the title of one of RudyardKipling's Just So stories.
斑馬為什么會長條紋捏這聽上去有點像Rudyard Kipling的書《原來如此》里面文章的標題。
Sadly, it isn't, so the question has, instead,been left to zoologists.
可惜啊，這不是其中的標題，所以這個問題的答案就成了動物學家的任務。
But they, too, have let their imaginations rip. Somehave suggested camouflage.
然而，這些動物學家們也是天馬行空。一些人認為是保護色。
Others suggest they are a way to display anindividual's fitness.
其他人則認為條紋是一種個體屬性的彰顯方式。
Irregular stripes would let potential mates know thatsomeone was not up to snuff.
不規則的條紋給潛在伴侶傳遞出不達標的信息。
One researcher proposed that stripes are to zebrawhat faces are to people,
有位研究人員認為斑馬的條紋就像人的臉一樣，
allowing them to recognise each other, since everyanimal has a unique stripe-print.
由于每個斑馬的條紋都獨一無二，可以讓同類彼此辨認。
Another even speculated that predators mightget dizzy watching a herd of stripes gallop by.
還有些人甚至認為捕食者看到一群條紋在面前飛奔會暈頭轉向。
There is,however, one other idea: that stripes are a sophisticated form of flyrepellent.
但是還有這樣一種想法：條紋是一種精致的防蠅器。
It was originally dreamed up in the 1980s, but never proved.
這種想法產生于20世紀80年代，但是從未被證明。
Now, ateam of investigators led by Gabor Horvath of Eotvos University in Budapestreport in the Journal of Experimental Biology thatthey think they have done so.
現在，由坐落于Budapest的Eotvos大學的Gabor Horvath帶領著一組研究人員在《實驗生物學報》上發表了一篇論文認為他們證明了這一想法。
The original suggestion was that stripes repel tsetse flies.
原本的猜想是說條紋是為了避免舌蠅。
These insectscarry sleeping sickness, which is as much a bane of ungulates as it is of people.
這些小昆蟲帶有昏睡病，對人類和有蹄類動物同樣致害。
But tsetses are not the only dipteran foes of zebra and,
但是舌蠅并非是斑馬唯一的長著翅膀的敵人，
since they arerarely found in the meadows of Hungary,
因為舌蠅在匈牙利的草原上并不常見。
Dr Horvath plumped for studying analmost equally obnoxious alternative: the horsefly.
Horvath轉而研究一種同樣惱人的替代品：馬蠅。
Horseflies, too, transmit disease.
馬蠅也同樣傳播疾病。
They also bite incessantly, thuskeeping grazing beasts from their dinner.
它們屬于寄生式叮咬，因此使得這些動物進食減少。
Indeed, previous research has shownthat fly attacks on horses and cattle reduce their body fat and milkproduction.
的確有研究表明被馬蠅襲擊的馬和牛出現了身體脂肪和產奶量下降的現象。
Such research has also shown something odd:
這些研究還出現了一些奇怪的現象：
horseflies attack blackhorses in preference to white ones.
相對于白馬，馬蠅更喜歡叮咬黑馬。
That fact got Dr Horvath wondering how theywould react to a striped horse—in other words, a zebra.
這一事實使得Horvath博士十分好奇馬蠅會對一個條紋馬，也就是斑馬作何反應。
Actual zebra are hard to experiment on.
很難對真實的斑馬做實驗。
They insist on moving around andswishing their tails.
它們一直在動來動去并且甩著尾巴。
The team therefore conducted their study using inanimateobjects.
因此這組研究人員用非生命體來進行實驗。
Some were painted uniformly dark or uniformly light,
一些實驗對象被涂成純白色或者純黑色，
and some hadstripes of various widths.
還有一些則被涂成寬度各異的條紋圖案。
Some were plastic trays filled with salad oil.
其中有些是充滿色拉油的塑料架子。
Some were glue-covered boards. And some wereactual models of zebra.
一些是膠合紙板做的。還有一些是真實的斑馬。
They put these objects in a field infested withhorseflies and counted the number of insects they trapped.
他們把這些實驗對象放到一個充滿馬蠅的場地，然后計算被吸引的馬蠅數目。
Their first discovery was that stripes attracted fewer flies than solid,uniform colours.
他們第一個發現是條紋的比純色的吸引的馬蠅少。
As intriguingly, though, they also found that the leastattractive pattern of stripes was precisely those of the sort of width found onzebra hides.
然而，耐人尋味的是他們還發現吸引力最小的條紋花式正是斑馬身上的條紋樣式。
Zebra stripes do, therefore, seem to repel horseflies.
因此，斑馬的條紋看起來真的能夠防馬蠅。
Exactly why is unclear.
至于為什么會這樣還是個謎團。
But Dr Horvath thinks it might be related to a horsefly'sability to see polarised light,
但是Horvath博士認為這可能與馬蠅識別偏振光的能力有關，
which imposes a sense of horizontal andvertical on an image.
偏振光是從水平和垂直方向打在畫面上的。
Horseflies are known to prefer horizontal polarisedlight.
眾所周知馬蠅偏向于水平偏振光。
Possibly, the mostly vertical stripes on a zebra confuse the fly's tinybrain and thus stop it seeing the animal.
所以極有可能是斑馬身上垂直的條紋迷惑了馬蠅的小腦袋，因此阻礙了馬蠅發現斑馬。
Another obvious question, though, is why other species have not evolvedthis elegant form of fly repellent,
然而，還有一個顯而易見的問題就是為什么其他的物種沒有進化出來這種精致的防蠅方式，
and what the consequences would have beenif they had.
以及如果其他物種也進化成這樣的后果。
If humans, for example, were black-and-white striped,
例如，如果人類是黑白條紋的，
then thehistory of intercommunal violence the species has suffered when different raceshave met might not have been quite as bad.
那么當不同種族相遇而遭受的兩族間的暴力歷史或許也沒那么壞。
One for Kipling to have pondered,perhaps?
這也許是Kipling需要思考的一個問題？
