Name: Why Don't Any Animals Have Wheels?
Uploaded: 2020-03-28T09:33:57.000Z
Duration: 5 min 51 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Hey, Vsauce, Michael here, and today we are going to ask a question—

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

What's really paradoxical about this question

is that us humans seem pretty technologically advanced.

We've mastered the wheel, but we have yet to design something

which is why this contraption seems so eerie.

It may be the closest we have come to mimicking

what nature is already quite natural with.

Of course, nature, the source of these miraculous limbs

that we have yet to adequately reproduce,

The wheel gives a mechanical advantage to the user,

allowing them to move heavy things more easily,

but if the wheel is so simple and seems like such a no-brainer,

Well, to be sure, let's take a look at the wheel spider.

When escaping from a predator, this spider will turn its body

into what is essentially a tire rolling downhill.

These things roll around in the wind, spreading seeds everywhere.

An even crappier example is the dung beetle,

who takes pieces of poop and turns them into rollable balls

But those are examples of rolling, not wheels

Wheels on axles— something that's a part of a whole,

and can spin indefinitely in one direction

without having to wind itself back again.

Bacterial flagella actually operate in this manner,

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

which brings us to the first problem of finding wheels on animals.

How can a living wheel be completely separate from the animal

and still receive nutrients and expel waste?

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

the animal produced, like fingernails or hair,

how would it build into the shape of a wheel

while maintaining separation from the host?

For that matter, how does developing a wheel

I mean, look at a giraffe— having a neck

that's just a little bit longer still means

that you'll be able to reach food that's a bit higher,

and will have more babies, making longer necks more common.

But if your mutation is a wheel that's only a little bit round,

Think of it this way— in order for a wheel

to be useful for movement, it sort of requires

like a road or rails, the wheel falls short,

and wings and fins and limbs do a better job

they had little use for it across rough terrain

a vehicle that uses no wheels and is carried by people or animals.

Fancy, rich people would get carried around

in chair sedans, but another type of litter

that would help you carry, say, wounded soldiers

The modern-day stretcher is an example of a litter.

Okay, so in order for the wheels on your body to be useful,

So what gives, animals? Why didn't you ever build roads?

I mean, you guys are capable of some pretty awesome things—

Well, this question is fundamental to Richard Dawkins' analysis

A nest, a burrow, a dam— these are things that you can defend;

that you can build and then only use for your own benefit.

Because hey, you were smart enough and industrious enough to build it,

but roads can be used by anything that stumbles upon it.

I mean, you lost energy and resources to build that road,

while a moocher can just come up and use it anyway

and have time left to make a bunch of babies and prosper.

So the road is a really cool example of how humans got benefits

not just for themselves, but for everyone.

have ever invented taxes— money that we force others to pay

to build services that they might not even use.

So the next time you see a wheel, say, "Thanks, wheel.

"You're a great symbol of the fact that humans can cooperate