为什么没有长轮子的动物？：英语精读讲义

Hey, Vsauce.

嘿，Vsauce。

Michael here, and today we are going to ask a question.

我是 Michael，今天我们要来问一个问题。

Why don't any animals have wheels?

为什么没有任何动物长着轮子？

I mean, animals use a plethora of complicated locomotive techniques, 講解

我的意思是，动物有各种各样复杂的移动方式，

slithering, fins, legs, wings,

比如蜿蜒爬行、用鳍、用腿、用翅膀，

but yet no animal has wheels. 語法

可偏偏没有任何动物长着轮子。

What's really paradoxical about this question 語法

这个问题真正矛盾的地方

is that us humans seem pretty technologically advanced,

在于我们人类似乎已经拥有相当先进的技术，

we've mastered the wheel,

我们掌握了轮子，

but we have yet to design something 語法

但至今还没设计出一种东西，

that fully takes advantage of the limb, 短語搭配

能把肢体的优势发挥到极致，

which is why this contraption seems so eerie. 表達脈絡

所以这台装置才显得如此诡异。

It may be the closest we have come 語法

这或许是我们迄今为止

to mimicking what nature is already quite natural with.

最接近模仿大自然天生本领的一次尝试。

Of course, nature,

当然，大自然

the source of these miraculous limbs

创造了这些神奇的肢体，

that we have yet to adequately reproduce,

而我们至今还无法充分复现它们，

doesn't use wheels.

可大自然并不使用轮子。

The wheel gives a mechanical advantage to the user, 用詞

轮子能给使用者带来机械优势，

allowing them to move heavy things more easily.

让他们更轻松地移动重物。

But if the wheel is so simple

但如果轮子如此简单，

and seems like such a no-brainer, 習語

看起来又是这么显而易见的选择，

why don't any animals have them?

为什么没有任何动物长出轮子呢？

Well, to be sure, 表達脈絡

不过，为了确认一下，

let's take a look at the wheel spider.

我们来看看轮蛛。

When escaping from a predator,

逃避捕食者时，

this spider will turn its body 短語搭配

这种蜘蛛会把身体变成

into what is essentially a tire rolling downhill.

一个活像从山坡上滚下去的轮胎。

And who can forget tumbleweeds? 表達脈絡

还有谁会忘记风滚草呢？

These things roll around in the wind

它们随风四处滚动，

spreading seeds everywhere.

把种子撒得到处都是。

An even crappier example is the dung beetle, 用詞

还有个更“屎”的例子，那就是蜣螂，

who takes pieces of poop and turns them

它会把一块块粪便做成

into rollable balls that can be easily moved.

可以滚动、方便搬运的球。

But those are examples of rolling,

但这些只是“滚动”的例子，

not wheels as we are looking for them today.

并不是我们今天要找的那种轮子。

Wheels on axles, 用詞

我们要找的是装在轴上的轮子，

something that's a part of a whole,

它是整体的一部分，

but yet exists independently of it 短語搭配

却又独立于整体存在，

and can spin indefinitely in one direction

可以朝一个方向无限旋转，

without having to wind itself back again. 語法

而不必再反向转动来复位。

Bacterial flagella actually operate in this manner, 講解

细菌的鞭毛其实就是这样运作的，

but we don't see it in any larger life form,

但在任何更大的生命体中，我们都看不到这种结构，

which brings us to the first problem 表達脈絡

这就引出了在动物身上

of finding wheels on animals.

寻找轮子时遇到的第一个难题。

How can a living wheel be completely separate

一个有生命的轮子要如何与动物彻底分离，

from the animal and still receive nutrients

同时还能从动物身上获取营养

and expel waste?

并排出废物？

Or, if that wheel was made out of a dead material 短語搭配

又或者，如果这个轮子由某种无生命的材料构成，

the animal produced, like fingernails or hair,

这种材料由动物生成，比如指甲或毛发，

how would it build into the shape of a wheel

它要如何形成轮子的形状，

while maintaining separation from the host? 語法

同时又与宿主保持分离？

For that matter, 表達脈絡

再说了，

how does developing a wheel on your body

在身体上逐渐形成一个轮子，

help you along the way? 習語

在演化过程中对你有什么帮助？

I mean, look at a giraffe.

我的意思是，看看长颈鹿。

Having a neck that's just a little bit longer

脖子只要稍微长一点，

still means that you'll be able to reach food

你依然能够到

that's a bit higher,

位置更高一点的食物，

you'll have more food, will live longer,

你就会有更多食物，也会活得更久，

and will have more babies,

还会生下更多后代，

making longer necks more common. 語法

于是长脖子就会变得越来越普遍。

But if your mutation is a wheel 用詞

但如果你的突变是一个

that's only a little bit round,

只稍微有点圆的轮子，

it doesn't provide the same benefit.

它就无法带来同样的好处。

It doesn't equal you making more babies.

它不会让你生下更多后代。

And as much as I hate to admit it, 語氣意圖

尽管我很不愿承认，

the wheel may be a bit overrated.

轮子可能确实有点被高估了。

Think of it this way. 表達脈絡

可以这样想。

In order for a wheel to be useful for movement, 語法

要让轮子在移动中派上用场，

it sort of requires a prior invention, roads. 語氣意圖

某种程度上还得先有另一项发明：道路。

Without a smooth surface to roll on, 語法

如果没有平滑的表面可供滚动，

like a road or rails, the wheel falls short, 習語

比如道路或轨道，轮子就不太好使了，

and wings and fins and limbs do a better job 短語搭配

而翅膀、鳍和四肢

for the terrain found on Earth.

更适合地球上的各种地形。

Even when humans knew about the wheel,

即使人类已经知道轮子，

they had little use for it across rough terrain 短語搭配

也很少用它穿越崎岖地形

or muddy, debris-ridden streets, 用詞

或泥泞、满是杂物的街道，

which is why wealthy people in the past

所以过去的有钱人

simply got carried around in litter.

干脆让人用一种叫“litter”的东西抬着走。

No, not rubbish.

不，不是“垃圾”。

A litter, 用詞

这里的“litter”指的是抬行载具，

a vehicle that uses no wheels

一种没有轮子的交通工具，

and is carried by people or animals.

由人或动物抬着走。

Fancy rich people would get carried around

讲究排场的富人会被人抬着，

in chair sedans, 文化背景

乘坐轿子四处走，

but another type of litter

但还有另一种抬行载具，

was simply a sling made out of fabric

只是一条用布做成的吊带，

that would help you carry,

可以帮你运送，

say, wounded soldiers 用詞

比如说受伤的士兵，

across the terrain of a battlefield.

带他们穿越战场上的地形。

The modern day stretcher is an example of a litter.

现代担架就是这类载具的一种。

Okay, so in order for the wheels on your body

好了，所以要让你身上的轮子

to be useful, you have to build roads.

真正派上用场，你就必须修路。

So, what gives animals? 習語

所以，动物们，到底怎么回事？

Why didn't you ever build roads?

你们为什么从来不修路？

I mean, you guys are capable of some pretty awesome things, 短語搭配

你们明明能做出一些相当了不起的东西，

complicated burrows, nests, dams.

比如复杂的洞穴、巢穴和水坝。

Why didn't you ever build roads?

为什么就是不修路呢？

Well, this question is fundamental

其实，这个问题是

to Richard Dawkins' analysis

Richard Dawkins 分析

of the wheeled animal problem.

“轮式动物难题”时的核心。

He says that the problem with roads

他说，道路的问题

is that they're not selfish enough. 文化背景

在于它们不够自私。

A nest, a burrow, a dam,

巢、洞穴和水坝，

these are things that you can defend,

都是你能够守住的东西，

that you can build and then only use for your own benefit, 短語搭配

你可以把它们建好，只让自己从中受益，

because hey, you were smart enough

因为，嘿，是你足够聪明，

and industrious enough to build it. 語法

也足够勤劳，才能把它们建起来。

But roads can be used by anything

但任何生物都可以使用道路，

that stumbles upon it. 短語動詞

只要它碰巧遇到了。

I mean, you lost energy and resources

我的意思是，你耗费了能量和资源

to build that road,

来修建那条路，

while a moocher can just come up 用詞

可一个想占便宜的家伙随时都能冒出来，

and use it anyway and have time left

照样使用这条路，还能省下时间，

to make a bunch of babies and prosper. 短語搭配

生下一大堆后代，繁衍兴旺。

So, the road is a really cool example

所以，道路是一个特别棒的例子，

of how humans got benefits from breaking the mold 習語

它说明人类如何通过打破常规而获益，

and doing things not just for themselves, 語法

不再只为自己做事，

but for everyone.

而是为所有人做事。

In fact, of all the animals,

事实上，在所有动物中，

only humans have ever invented taxes,

只有人类发明了税收，

money that we force others to pay

也就是我们强迫别人缴纳的钱，

to build services that they might not even use.

用来提供他们甚至可能根本不用的公共服务。

So, the next time you see a wheel, 語法

所以下次看到轮子时，

say thanks, wheel.

记得说声：“谢谢你，轮子。”

You're a great symbol of the fact

你是一个绝佳的象征，证明

that humans can cooperate and be unselfish.

人类可以合作，也可以无私。

And as always, thanks for watching.

一如既往，感谢观看。

I wheel-y mean that. 習語

我真的是这么“轮”为的。