One of the most extraordinary examples of beauty happening in the natural world

自然界中关于美的发生最特别的一个例子

is the courtship display song of the Club-winged Manakin.

就是梅花翅侏儒鸟的示爱歌曲

The club-winged manakin is a South American bird that sings with its wings.

梅花翅侏儒鸟是南美的一种鸟 会用翅膀唱歌

The female club-winged does all the nesting and builds the nest and lays the eggs and takes care of them all on her own,

雌梅花翅侏儒鸟负责筑巢下蛋 并且独自照顾鸟蛋

but she chooses among available mates based on the songs they sing.

但它会根据雄梅花翅侏儒鸟的歌声来选择配偶

But they sing with their wing feathers in a very special way:

雄梅花翅侏儒鸟用翅膀上的羽毛唱歌的方式很独特：

by shaking their wing feathers rapidly over their back

它们会快速抖动背部的翼羽

they create an “electronic” sound that sounds like “Bip! Bip! WAAANG”

发出一种类似“电子乐”的声音 听起来像是“哔噗哔噗 WAAANG”

that rings out of the forest, and yet this is actually produced by the wing feathers rubbing together.

这种声音能传至整片森林 但它其实是通过摩擦翅膀上的羽毛发出的

This is interesting because it shows that beauty can be innovative.

这个很有意思 它说明美是有创新性的

Birds have been singing songs, vocal songs with their syrinx for something like 80 million years,

8000多万年以来 鸟类都会唱歌 用它们的鸣管唱有声歌曲

but this bird has essentially abandoned vocal songs to create music in a whole new way with its wing feathers.

但这种鸟却摈弃了有声歌曲 转而以全新的方式用它的翼羽创造出了音乐

Studies have shown that as we look inside the body of the male club-winged manakin

研究表明 如果我们看一下雄梅花翅侏儒鸟的身体

the wing bones have been greatly altered in order to make this sound.

会发现为了发出这种声音 它们的翼骨发生了很大变化

What this means is that beauty is not only skin deep:

这说明美不只是表面的：

in order to make these beautiful attractive sounds

为了发出这种迷人动听的声音

the wing bones have become elaborated and even solid like ivory.

侏儒鸟的翼骨变精致了许多 甚至像象牙一样坚固

This is a big deal because all birds have hollow wing bones:

这种现象可不一般 因为所有鸟类的翼骨都是中空的：

even Velociraptor and T Rex have hollow arm bones,

连迅猛龙和霸王龙的臂骨都是中空的

so this is a design that goes back prior to the origin of birds and prior to the origin of flight!

所以中空翼骨的构造在鸟类出现之前 在飞行出现之前就存在了

But flying birds all maintained hollow wing bones,

但时至今日 所有会飞的鸟类依然保留着中空的翼骨

but somehow or other the male club-winged manakin has abandoned them in order to produce his wing song.

唯有雄梅花翅侏儒鸟摈弃了这种构造 只为用它们的翅膀发出歌声

This is interesting because his wing bones are actually made worse at flying by the compromise to be beautiful,

这其实挺有意思的 因为向美做出了妥协 为了发出雌鸟喜欢的声音

in order to make the songs that females love.

所以它们的翅膀更不适合飞行了

Then the male has been dragged off that optimal design toward a new design,

雄梅花翅侏儒鸟偏离了最佳构造 转而采用一种新的构造

which functions less well at flying;

这种新构造更不擅长飞行

in other words the male has been made less capable at flight by female choice.

换句话说 因为雌鸟的择偶标准 导致雄鸟的飞行能力变差

That kind of investment or cost COULD be rationalized as another kind of “honesty,”

这种投资或者说代价可以被合理地解释为另一种“真诚”

a kind of handicap that indicates how good he is, that he can waste energy to make the wing bones.

用一种不利条件来彰显雄鸟的出色 彰显它宁愿浪费能量去形成这种翼骨

I wanted to test that idea by exploring what’s going on in female club-winged manakins.

我想研究一下雌梅花翅侏儒鸟 来测试这种观点是否正确

It turns out that female club wings have the same elaborate, thickened,

结果发现 雌梅花翅侏儒鸟有着跟雄鸟一样的精致 加厚

or wider wing bones as the males, yet they will never sing a wing song.

或者说更宽的翼骨 但它们却从来不用翅膀唱歌

How does that work?

这是为什么呢？

Well, it turns out that the wing bones develop in the embryo in the egg before the embryo becomes either male or female.

原来在鸟蛋的胚胎成为雌鸟或雄鸟之前 翼骨就已经在胚胎中形成了

And as a result when the female selects on the males that she likes with the song that she likes,

所以 当雌鸟根据它喜欢的歌曲选择它喜欢的雄鸟时

her female offspring will also inherit bizarre wing bones, and yet they won’t be made better by them.

它的雌性后代也会继承这种奇怪的翼骨 但它们并不会因此得到更好的进化

They will never profit from them.

这对它们一点好处都没有

So in this case of the club-winged manakin, both males and females are made worse off as a result of mate choice.

所以在梅花翅侏儒鸟这个例子中 雄鸟和雌鸟都因为配偶选择被迫退化

I call this the “evolution of decadence”.

我把这种现象叫做“堕落的演化”

It’s an example of how mate choice or evolution by mate choice

这个例子说明 配偶选择或者根据配偶选择来演化

can work in an entirely opposite or opposing direction to natural selection.

会起到与自然选择完全相反的作用

I think that’s a case where we are driven to accept the idea that beauty happens.

在这种情况下 我们不得不接受美的发生这种观点