Evolving the wheel

[Rum]

Interesting question.
I can't think of a circumstance where it could evolve through natural selection, since it hasn't already.

It has several times. The main constrain is blood flow (or fluid transfer) to the moving part. In all cases where it has evolved, the scale was small enough that the fluid issue wasn't a problem.

Stephen J. Gould wrote a good essay on it from what I remember.

At the macro scale?

No. I think Gould gave 2-3 examples, including the flagellum. He gives a clear account of the many things standing in the way of wheels evolving on the macro scale.

It's about 7 years since I read it though, so I don't remember the details.

I mentioned the fucking flagellum but no one took me seriously. Do I have a credibility issue?

I find it strange that you should ask the question.

[cowiz]

I find it strange that you should ask the question.

Phew that's a relief, for a moment I thought I might have had one. Thanks for clarifying

[Gawdzilla Sama]

As I was walking the dogs this evening I found myself marvelling at their leg action and at how evolution had developed locomotion in this form. It got me wondering though.

Do you think that life (on earth) would be able to evolve the wheel as a form of locomotion?

E.E. "Doc" Smith described the Zabriskan Fotema. You may be able to Google that.

[PsychoSerenity]

Do you think that life (on earth) would be able to evolve the wheel as a form of locomotion?

How about not on earth? I would imagine it would be more likely on a planet with higher gravity - surfaces might be flatter, and lifting the body on legs would be less efficient. Perhaps some exoskeleton type creature could make the transition to the macro.

There might be alien crabs with wheels somewhere out there right now.

Watching us.

[mistermack]

I don't think anything tiny and aquatic really qualifies as a wheel.
To me, a wheel is a thing that rolls along the ground, and carries a load through the axle. So for a true wheel to evolve, the axle or wheel bearing would need to evolve alongside it. And one wheel is pretty useless, you would need at least two, for balance. And what would drive the wheel? You would still need legs, for propulsion, because you couldn't attach muscles directly to the wheel, they would twist up, along with the blood supply.
So you would need something like a rickshaw, with legs for propulsion, and two wheels at the back to carry the load.
And the wheels would have to be seperate from the 'cart', as no blood vessels could go from one to the other.
It's a highly unlikely and unecessary setup.
it would stand more chance in a water creature, where the wheels could be seperate colonies, feeding independently, but there is no advantage of a wheel underwater, as load carrying isn't that important.

So it's no surprise it hasn't evolved in the true sense of a wheel.
.

[Rum]

I don't think anything tiny and aquatic really qualifies as a wheel.
To me, a wheel is a thing that rolls along the ground, and carries a load through the axle. So for a true wheel to evolve, the axle or wheel bearing would need to evolve alongside it. And one wheel is pretty useless, you would need at least two, for balance. And what would drive the wheel? You would still need legs, for propulsion, because you couldn't attach muscles directly to the wheel, they would twist up, along with the blood supply.
So you would need something like a rickshaw, with legs for propulsion, and two wheels at the back to carry the load.
And the wheels would have to be seperate from the 'cart', as no blood vessels could go from one to the other.
It's a highly unlikely and unecessary setup.
it would stand more chance in a water creature, where the wheels could be seperate colonies, feeding independently, but there is no advantage of a wheel underwater, as load carrying isn't that important.

So it's no surprise it hasn't evolved in the true sense of a wheel.
.

You raise one intriguing possibility - a symbiotic relationship where the 'wheels' are a different organism, but ultimately both organisms require the other to survive. Best option yet I think, however unlikely.

[Trolldor]

lawl.
"It doesn't fit my definition of a wheel and is therefore not a wheel".

[Pappa]

I don't think anything tiny and aquatic really qualifies as a wheel.

Even if it doesn't qualify as a wheel by a certain definition, it is still the vital precursor of a macro-wheel. Though, for various reasons macro-wheels are seen to be either impossible or so highly improbable they will never evolve, even in an environment in which they would be useful.

[GrahamH]

This is a sort of wheel, although it has no axle
[youtube]http://www.youtube.com/watch?v=I1RHmSm3 ... re=related[/youtube]

The problem is the axles. Muscles can't turn axles without a crank or ratchet mechanism, and lubrication and seals are a problem.

[Gawdzilla Sama]

This is a sort of wheel, although it has no axle
[youtube]http://www.youtube.com/watch?v=I1RHmSm3 ... re=related[/youtube]

The problem is the axles. Muscles can't turn axles without a crank or ratchet mechanism, and lubrication and seals are a problem.

So put the muscles on the rim of the wheel. (Think of an octopus-thingy that rolls.)

[GrahamH]

So put the muscles on the rim of the wheel. (Think of an octopus-thingy that rolls.)

How about a spider (gravity power only, it seems).
The Golden wheel spider

[GrahamH]

Rolling creatures

http://en.wikipedia.org/wiki/Terrestria ... on#Rolling

http://en.wikipedia.org/wiki/Category:Rolling_animals

http://en.wikipedia.org/wiki/Rotation_in_living_systems

[Rum]

So put the muscles on the rim of the wheel. (Think of an octopus-thingy that rolls.)

How about a spider (gravity power only, it seems).
The Golden wheel spider

Well I'll be damned. It isn't a million miles from this to some sort of 'wheel', and nature, as every, does the unpredictable.

[Thinking Aloud]

The other possibility is that a creature develops the ability to secrete something wheel-like (as a by-product of other secretions no doubt at first) that it can then mount on its legs or elsewhere for motion...

[Trolldor]

There's no reason a creature can't evolve a wheel operating on an axis, we simply just can't picture how it would work.