為什麼沒有長輪子的動物？：英語精讀講義

Hey, Vsauce.

嘿，Vsauce。

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

我是 Michael，今天我們要來問一個問題。

Why don't any animals have wheels?

為什麼沒有任何動物有輪子？

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

我是說，動物有各式各樣複雜的移動方式，

slithering, fins, legs, wings,

像是蜿蜒爬行、用鰭、用腿、用翅膀，

but yet no animal has wheels. 文法

可是偏偏沒有任何動物有輪子。

What's really paradoxical about this question 文法

這個問題真正矛盾的地方

is that us humans seem pretty technologically advanced,

在於我們人類的科技看起來相當先進，

we've mastered the wheel,

我們已經掌握了輪子，

but we have yet to design something 文法

卻還沒有設計出一種東西，

that fully takes advantage of the limb, 片語搭配

能把肢體的優勢發揮到極致，

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

所以這台裝置才會顯得這麼詭異。

It may be the closest we have come 文法

這或許是我們至今為止

to mimicking what nature is already quite natural with.

最接近模仿大自然天生本領的一次嘗試。

Of course, nature,

當然，大自然

the source of these miraculous limbs

創造了這些神奇的肢體，

that we have yet to adequately reproduce,

而我們至今還無法充分重現它們，

doesn't use wheels.

可大自然並不使用輪子。

The wheel gives a mechanical advantage to the user, 用詞

輪子能為使用者帶來機械優勢，

allowing them to move heavy things more easily.

讓他們更輕鬆地移動重物。

But if the wheel is so simple

但如果輪子這麼簡單，

and seems like such a no-brainer, 慣用語

看起來又是如此理所當然的選擇，

why don't any animals have them?

為什麼沒有任何動物有輪子呢？

Well, to be sure, 表達脈絡

不過，為了確認一下，

let's take a look at the wheel spider.

我們來看看輪蛛。

When escaping from a predator,

逃離掠食者時，

this spider will turn its body 片語搭配

這種蜘蛛會把身體變成

into what is essentially a tire rolling downhill.

一個活像正滾下山坡的輪胎。

And who can forget tumbleweeds? 表達脈絡

還有，誰能忘得了風滾草呢？

These things roll around in the wind

這些植物會隨風到處滾動，

spreading seeds everywhere.

把種子撒得到處都是。

An even crappier example is the dung beetle, 用詞

還有個更「屎」的例子，就是糞金龜，

who takes pieces of poop and turns them

牠會把一塊塊糞便做成

into rollable balls that can be easily moved.

可以滾動、方便搬運的球。

But those are examples of rolling,

但這些只是「滾動」的例子，

not wheels as we are looking for them today.

並不是我們今天要找的那種輪子。

Wheels on axles, 用詞

我們要找的是裝在軸上的輪子，

something that's a part of a whole,

它是整體的一部分，

but yet exists independently of it 片語搭配

卻又獨立於整體存在，

and can spin indefinitely in one direction

可以朝一個方向無限旋轉，

without having to wind itself back again. 文法

而不必再反向轉回去。

Bacterial flagella actually operate in this manner, 講解

細菌的鞭毛其實就是這樣運作的，

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

但我們在任何更大型的生命體中都看不到這種構造，

which brings us to the first problem 表達脈絡

這就帶出了在動物身上

of finding wheels on animals.

尋找輪子時遇到的第一個難題。

How can a living wheel be completely separate

一個有生命的輪子要怎麼跟動物徹底分離，

from the animal and still receive nutrients

同時又能從動物身上獲取養分

and expel waste?

並排出廢物？

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

或者，如果這個輪子是由某種無生命的材料構成，

the animal produced, like fingernails or hair,

這種材料由動物生成，例如指甲或毛髮，

how would it build into the shape of a wheel

它要怎麼形成輪子的形狀，

while maintaining separation from the host? 文法

同時又跟宿主保持分離？

For that matter, 表達脈絡

再說，

how does developing a wheel on your body

在身體上逐漸形成一個輪子，

help you along the way? 慣用語

在演化過程中對你有什麼幫助？

I mean, look at a giraffe.

我是說，看看長頸鹿。

Having a neck that's just a little bit longer

脖子只要稍微長一點，

still means that you'll be able to reach food

你仍然能吃到

that's a bit higher,

位在更高處一點的食物，

you'll have more food, will live longer,

你會有更多食物、活得更久，

and will have more babies,

也會生下更多後代，

making longer necks more common. 文法

於是長脖子就會變得愈來愈普遍。

But if your mutation is a wheel 用詞

但如果你的突變是一個

that's only a little bit round,

只有稍微圓一點的輪子，

it doesn't provide the same benefit.

它就無法帶來同樣的好處。

It doesn't equal you making more babies.

它不會讓你生下更多後代。

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

雖然我很不願意承認，

the wheel may be a bit overrated.

輪子可能真的有點被高估了。

Think of it this way. 表達脈絡

可以這樣想。

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

要讓輪子在移動時派上用場，

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

某種程度上還得先有另一項發明：道路。

Without a smooth surface to roll on, 文法

如果沒有平滑的表面可供滾動，

like a road or rails, the wheel falls short, 慣用語

像是道路或軌道，輪子就不太好用了，

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

而翅膀、鰭和四肢

for the terrain found on Earth.

更適合地球上的各種地形。

Even when humans knew about the wheel,

就算人類已經知道輪子，

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

也很少用它穿越崎嶇地形

or muddy, debris-ridden streets, 用詞

或泥濘、滿是雜物的街道，

which is why wealthy people in the past

所以過去的有錢人

simply got carried around in litter.

乾脆讓人用一種叫「litter」的東西抬著走。

No, not rubbish.

不，不是「垃圾」。

A litter, 用詞

這裡的「litter」指的是抬行載具，

a vehicle that uses no wheels

一種沒有輪子的交通工具，

and is carried by people or animals.

由人或動物抬著走。

Fancy rich people would get carried around

講究排場的富人會由人抬著，

in chair sedans, 文化背景

坐轎子到處走，

but another type of litter

但還有另一種抬行載具，

was simply a sling made out of fabric

就只是一條用布做成的吊帶，

that would help you carry,

可以幫你搬運，

say, wounded soldiers 用詞

比方說受傷的士兵，

across the terrain of a battlefield.

帶他們穿越戰場上的地形。

The modern day stretcher is an example of a litter.

現代擔架就是這類載具的一種。

Okay, so in order for the wheels on your body

好，所以要讓你身上的輪子

to be useful, you have to build roads.

真正派上用場，你就必須鋪路。

So, what gives animals? 慣用語

所以，動物們，這是怎麼回事？

Why didn't you ever build roads?

你們為什麼從來不鋪路？

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

你們明明能做出一些非常厲害的東西，

complicated burrows, nests, dams.

像是複雜的洞穴、巢穴和水壩。

Why didn't you ever build roads?

為什麼就是不鋪路呢？

Well, this question is fundamental

其實，這個問題是

to Richard Dawkins' analysis

Richard Dawkins 分析

of the wheeled animal problem.

「輪式動物難題」時的核心。

He says that the problem with roads

他說，道路的問題

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

在於它們不夠自私。

A nest, a burrow, a dam,

巢、洞穴和水壩，

these are things that you can defend,

都是你能夠守住的東西，

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

你可以把它們蓋好，只讓自己從中受益，

because hey, you were smart enough

因為，嘿，是你夠聰明，

and industrious enough to build it. 文法

也夠勤奮，才能把它們蓋起來。

But roads can be used by anything

但任何生物都可以使用道路，

that stumbles upon it. 片語動詞

只要牠碰巧遇到了。

I mean, you lost energy and resources

我是說，你耗費了能量和資源

to build that road,

來鋪那條路，

while a moocher can just come up 用詞

可一個想佔便宜的傢伙隨時都能冒出來，

and use it anyway and have time left

照樣使用這條路，而且還能省下時間，

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

生下一大堆後代、繁衍興旺。

So, the road is a really cool example

所以，道路是一個非常棒的例子，

of how humans got benefits from breaking the mold 慣用語

它說明人類如何打破常規並從中受益，

and doing things not just for themselves, 文法

不再只為自己做事，

but for everyone.

而是為所有人做事。

In fact, of all the animals,

事實上，在所有動物中，

only humans have ever invented taxes,

只有人類發明了稅收，

money that we force others to pay

也就是我們強迫別人繳納的錢，

to build services that they might not even use.

用來提供他們甚至可能根本不用的服務。

So, the next time you see a wheel, 文法

所以下次看到輪子時，

say thanks, wheel.

記得說：「謝謝你，輪子。」

You're a great symbol of the fact

你是一個絕佳的象徵，證明

that humans can cooperate and be unselfish.

人類能夠合作，也能無私。

And as always, thanks for watching.

一如往常，謝謝收看。

I wheel-y mean that. 慣用語

我真的是這麼「輪」為的。