科学美国人60秒 SSS 斑马的颜色可以驱散苍蝇（在线收听）

This is Scientific American's 60-second Science, I'm Mark Stratton.

这里是科学美国人——60秒科学系列，我是马克·斯特拉顿。

Everyone loves zebras. No doubt it’s the natty stripes.

每个人都喜欢斑马。毫无疑问是整洁的条纹。

But recent research into why the stripes exist indicates that the markings may be something of a mixed blessing for the zebras that wear them.

但最近对条纹存在原因的研究表明，这些斑纹对于长有条纹的斑马来说，可能是喜忧参半。

New research adds to evidence against old ideas that somehow stripes cool them down or confuse predators, such as lions—confusing lions would be nice for them.

新的研究增加了反对旧观点的证据，这些旧观点认为条纹以某种方式会使它们降温或迷惑捕食者，比如狮子-迷惑狮子对它们是件好事。

But the good news is that a group of researchers have additional evidence in support of a hypothesis they proposed in 2014:

但好消息是，一组研究人员有更多证据支持他们在2014年提出的一个假设：

stripes seem to confuse biting flies, causing cause them to overfly or crash into the zebras.

条纹似乎会让叮咬的苍蝇感到困惑，导致它们飞越斑马或撞上斑马。

The study is in the journal Proceedings of the Royal Society B.

这项研究发表在英国皇家学会学报B期刊上。

Various ideas have been tossed around in the last 150 years about the African equids’ stripes.

在过去的150年里，关于非洲马科动物身上的条纹有各种各样的观点。

“This debate goes right back to the birth of evolution, with Darwin and Wallace exchanging letters on the subject.”

“这场争论可以追溯到进化论的诞生，当时达尔文和华莱士在这个问题上交换过信件。

Martin How, a biologist who studies animal vision at the University of Bristol, and lead author of the study.

布里斯托尔大学研究动物视觉的生物学家马丁·豪是这项研究的第一作者。

How and his colleagues sought a mechanism for how stripes cause insect confusion.

豪和他的同事们正在寻找一种机制来解释条纹是如何引起昆虫困惑的。

They began with domestic horses in Great Britain.

他们从英国的家马开始研究。

They covered the horses with rugs featuring an array of designs: from single-color black or grey to checked patterns and, of course, zebra stripes.

他们在马身上铺上了具有一系列设计的地毯：从黑色（单色）或灰色到格子图案，当然还有斑马条纹。

The researchers then recorded videos of horseflies trying to get at the horses.

研究人员随后录制了马蝇试图接近马的视频

“When we looked in detail at what these zebra stripes were doing to horseflies as they were flying, coming in to land,

“当我们仔细观察这些斑马条纹在马蝇飞行、降落时对它们的影响时，

we found that horseflies were flying much faster as they came to land on striped patterns than they were when they were landing on grey or black.”

我们发现，当马蝇降落在条纹图案上时，飞行速度要比它们降落在灰色或黑色图案上时快得多。”

Faster and more erratically.

更快，更不稳定。

The flies made successful landings much less frequently on the horses in stripes than on the solids.

与纯色的马相比，苍蝇在条纹马身上成功着陆的频率要低得多。

But there’s more: “And interestingly, we also in our recent work found that this also applies to checked patterns.

但还有更多：“有趣的是，我们在最近的工作中也发现，这也适用于格子图案。

So it seems there’s something about black and white patterns that’s really confusing these flies.”

所以似乎黑白图案真的让这些苍蝇迷惑不解。

One assumption was that stripes affect the flies’ optic flow via a process known as the aperture effect.

一种假设是条纹通过一种称为孔径效应的过程影响苍蝇的光流。

That effect creates a visual illusion akin to a barbershop’s pole, inducing distortion and causing flies to misjudge landings upon striped surfaces.

这种效果创造了一种类似于理发店杆子的视觉错觉，导致扭曲，并导致苍蝇误判降落在条纹表面上。

But crediting the aperture effect’s ability to discombobulate biting flies appears to be flawed—because the researchers found that checked surfaces were just as effective at repelling flies as were stripes.

但是，认为孔径效应能够让叮咬的苍蝇感到困惑似乎是有缺陷的——因为研究人员发现，格子状的表面和条纹状的表面在驱赶苍蝇方面同样有效。

Once we’d lost the aperture effect as a possible explanation for how zebra stripes affect fly behaviour, we then had to turn to other suggestions.

一旦我们失去了孔径效应作为斑马条纹如何影响飞翔行为的可能解释，我们就不得不求助于其他观点。

So there might be some other kind of illusion that is happening in the eyes of these flies.

所以这些苍蝇的眼睛里可能有其他的幻觉。

And it could also be that the stripes are disrupting the search pattern that these flies need to try and find a host.

也可能是这些条纹打乱了这些苍蝇试图找到宿主所需的搜索模式。

So we’re undertaking more experiments now to try and find out which of those is the case.

因此，我们现在正在进行更多的实验，试图找出其中哪一种是正确的。

Whatever the result, evolution had a good reason to make zebras a horse of a different color.

无论结果如何，进化有充分的理由让斑马变成不同颜色的马。

Thanks for listening for Scientific American's 60-second Science. I'm Mark Stratton.

谢谢大家收听科学美国人——60秒科学。我是马克·斯特拉顿。