Why didn't animals evolve wheels?

[Brian Peacock]

The human shoulder is comprised of two joints, the glenohumeral and the acromioclavicular, which allow it to both circumduct in a large circle out to a vertical plane and to rotate around its axis at the shoulder. It is a true marvel of hominid evolution and an anatomical feature which is commonly granted the honour of being the most flexible joint in the human body. Although the glenohumeral joint consists of a ball-and-socket arrangement formed between the head of humerus and the glenoid fossa at the scapula, it is not encapsulated in the same way the head of femur is bound within the acetabulum of the pelvis. The arrangement of the joint and it's supporting structures afford the human shoulder unparalleled articulation and flexibility and in this sense it is quite reasonable to refer to it as a free-floating joint - though this of course does not mean it is somehow detached from the body or its circulatory or nervous systems etc.



Anyway, all I was saying is that an anatomical arrangement akin to the human shoulder could act as a hub for and evolved wheel, notwithstanding the usual qualification re evolutionary processes and all that blah.

[JimC]

Brian, the shoulder is not particularly free-floating. Your arm is connected to your torso by tendons, muscles and arteries. It will never evolve to become a wheel unless those become free-floating connections as well, and even then you'd need a further evolutionary development that will act like a drive shaft and more still that act like a motor.

[Seth]

Brian, the shoulder is not particularly free-floating. Your arm is connected to your torso by tendons, muscles and arteries. It will never evolve to become a wheel unless those become free-floating connections as well, and even then you'd need a further evolutionary development that will act like a drive shaft and more still that act like a motor.

Flagella do it.

[Brian Peacock]

... blah blah blah ...

Anyway, all I was saying is that an anatomical arrangement akin to the human shoulder could act as a hub for and evolved wheel, notwithstanding the usual qualification re evolutionary processes and all that blah.

Remember, I only used this as an example when pointing out that the apparent complexity of the 'wheel solution' is in itself no bar to evolutionary processes.

[pErvinalia]

The human shoulder is comprised of two joints, the glenohumeral and the acromioclavicular, which allow it to both circumduct in a large circle out to a vertical plane and to rotate around its axis at the shoulder. It is a true marvel of hominid evolution and an anatomical feature which is commonly granted the honour of being the most flexible joint in the human body. Although the glenohumeral joint consists of a ball-and-socket arrangement formed between the head of humerus and the glenoid fossa at the scapula, it is not encapsulated in the same way the head of femur is bound within the acetabulum of the pelvis. The arrangement of the joint and it's supporting structures afford the human shoulder unparalleled articulation and flexibility and in this sense it is quite reasonable to refer to it as a free-floating joint - though this of course does not mean it is somehow detached from the body or its circulatory or nervous systems etc.



Anyway, all I was saying is that an anatomical arrangement akin to the human shoulder could act as a hub for and evolved wheel, notwithstanding the usual qualification re evolutionary processes and all that blah.

How do the veins and arteries manage to go down the arm without getting twisted? Is there a bush/brush system like in electrical motors?

[Brian Peacock]

Because when you circumduct an arc on the vertical you also rotate the arm along its axis from the shoulder silly.

[pErvinalia]

Yeah, I actually thought of that while I was lying down this arvo. I wanted to get back on here and erase evidence of my question, but figured that was impossible, and then fell asleep anyway. Then forgot that I needed to get back on here before you got back here and pointed out the obvious.

[pErvinalia]

Actually, things are starting to come back to me now. I also figured you'd need basically (lets say 5 bone spokes) five ball joints in the central shoulder analogue, but because the spokes need to rotate through its lengthwise axis you'd need a ball joint at the joining point of the wheel bones as well. So 10 ball joints and all the associated bones, ligaments,, tendons, muscles etc. I reckon there's a pretty good reason why we didn't evolve wheels...

[Forty Two]

Perhaps there is a difficulty in evolving a system of hubs, axles and bearings that can spin around without veins and nerves getting all twisted up on themselves.

There is no particular difficulty for evolution, or a species, here. If we look at the bio-chemistry of even simple life forms, like an amoeba for example, we can see that the apparent complexity of a system is no bar to evolution if-and-only-if the evolution of the system over time continues to secure and/or enhance the species' survivability.

The wheel is not particularly complex. It's merely that in order for a biological organism to exist, it requires energy and waste to be transported around. Inherent in the design of a wheel is that it spins. It spins around a center point. So, where do you connect the pathway where energy goes from the body to the wheel without it getting tangled up when the wheel spins?

It's not complexity, it's an engineering problem.

That may be why there are examples of very complex organisms, but no examples of organisms with wheels. It's not the complexity. It's a design barrier.

Maybe there would be a way to have, like, an organism roll on wheels, but energy and waste can move from the wheel unit to the body via some kind of osmosis. But, then you'd have a permeable membrane almost constantly exposed to the environment. Or, perhaps some form of symbiosis could form, where the wheel is a self sufficient entity that doesn't need food from the body. However, then the wheel would need its own way to get food intake and waste output.

You can't take veiny creatures, though, and put wheels on them because it would be like taking electrical wires and running them from the car engine to the wheel itself. As the wheel spins, the wires would get wrapped up around the axle and rip off.

[Brian Peacock]

Perhaps there is a difficulty in evolving a system of hubs, axles and bearings that can spin around without veins and nerves getting all twisted up on themselves.

There is no particular difficulty for evolution, or a species, here. If we look at the bio-chemistry of even simple life forms, like an amoeba for example, we can see that the apparent complexity of a system is no bar to evolution if-and-only-if the evolution of the system over time continues to secure and/or enhance the species' survivability.

The wheel is not particularly complex. It's merely that in order for a biological organism to exist, it requires energy and waste to be transported around. Inherent in the design of a wheel is that it spins. It spins around a center point. So, where do you connect the pathway where energy goes from the body to the wheel without it getting tangled up when the wheel spins?

It's not complexity, it's an engineering problem.

That may be why there are examples of very complex organisms, but no examples of organisms with wheels. It's not the complexity. It's a design barrier.

Maybe there would be a way to have, like, an organism roll on wheels, but energy and waste can move from the wheel unit to the body via some kind of osmosis. But, then you'd have a permeable membrane almost constantly exposed to the environment. Or, perhaps some form of symbiosis could form, where the wheel is a self sufficient entity that doesn't need food from the body. However, then the wheel would need its own way to get food intake and waste output.

You can't take veiny creatures, though, and put wheels on them because it would be like taking electrical wires and running them from the car engine to the wheel itself. As the wheel spins, the wires would get wrapped up around the axle and rip off.

There's no reason to think that a wheel on an organism has to work in the same manner as a wheel on a car. As you know, evolution doesn't work to a plan like that, and I've given the example of the human shoulder joint to highlight that this feature of hominid anatomy can produce articulated movement analogous to that of a wheel, although I have also pointed out that even given this evolution is driven by the interplay of environmental circumstance and the necessity of any such evolbed locomotive 'solution' having survivability benefits for any organism operating under those environmental conditions. My comments above were only intended to correct any lingering or implicit assumptions about the apparent functional necessity of 'hubs, axles and bearings' etc as being insurmountable constraints on, or barriers to, evolution.

[Forty Two]

Perhaps there is a difficulty in evolving a system of hubs, axles and bearings that can spin around without veins and nerves getting all twisted up on themselves.

There is no particular difficulty for evolution, or a species, here. If we look at the bio-chemistry of even simple life forms, like an amoeba for example, we can see that the apparent complexity of a system is no bar to evolution if-and-only-if the evolution of the system over time continues to secure and/or enhance the species' survivability.

The wheel is not particularly complex. It's merely that in order for a biological organism to exist, it requires energy and waste to be transported around. Inherent in the design of a wheel is that it spins. It spins around a center point. So, where do you connect the pathway where energy goes from the body to the wheel without it getting tangled up when the wheel spins?

It's not complexity, it's an engineering problem.

That may be why there are examples of very complex organisms, but no examples of organisms with wheels. It's not the complexity. It's a design barrier.

Maybe there would be a way to have, like, an organism roll on wheels, but energy and waste can move from the wheel unit to the body via some kind of osmosis. But, then you'd have a permeable membrane almost constantly exposed to the environment. Or, perhaps some form of symbiosis could form, where the wheel is a self sufficient entity that doesn't need food from the body. However, then the wheel would need its own way to get food intake and waste output.

You can't take veiny creatures, though, and put wheels on them because it would be like taking electrical wires and running them from the car engine to the wheel itself. As the wheel spins, the wires would get wrapped up around the axle and rip off.

There's no reason to think that a wheel on an organism has to work in the same manner as a wheel on a car. As you know, evolution doesn't work to a plan like that, and I've given the example of the human shoulder joint to highlight that this feature of hominid anatomy can produce articulated movement analogous to that of a wheel, although I have also pointed out that even given this evolution is driven by the interplay of environmental circumstance and the necessity of any such evolbed locomotive 'solution' having survivability benefits for any organism operating under those environmental conditions. My comments above were only intended to correct any lingering or implicit assumptions about the apparent functional necessity of 'hubs, axles and bearings' etc as being insurmountable constraints on, or barriers to, evolution.

I didn't say it had to work the same way as it does in a car, and in fact that's the whole problem. It simply can't work the same way that it works on a car. The wheels on a car don't need to sustain themselves. A living wheel, like a living foot, has to receive food energy and get rid of waste.

A shoulder joint doesn't spin round like a wheel, so all the veins and sinew don't get tangled up.

The fact is that for living wheel to work, it has to function. Of course it doesn't have to have wheel bearings and antilock brakes. But, it does have to spin around and round. So, you need to attach the wheel to the body, and get it food energy and remove waste matter from the cells. With all other aspects of the animal body, food energy goes to the limbs via long tubes, and other long strands go there for nerves and such. the very act of spinning like a wheel makes wheels extraordinarily more of an engineering problem for living creatures than legs. Evolution would have to come up with a different way to fed the wheel organ, and remove waste products.

Maybe, for example, the connection could disconnect when the animal is going to roll. That is, you'd have like veins meet at a valve connector when the wheel is stationary, so blood can go in and out. Then, when the creature is going to move, the connection shuts and the veins disconnect and then the wheel spins and then they reconnect when the animal stops.

Maybe there is an osmosis thing where the wheel just sort of oozes stuff in and out.

For some reason, no such organisms have ever evolved.

[Brian Peacock]

Perhaps there is a difficulty in evolving a system of hubs, axles and bearings that can spin around without veins and nerves getting all twisted up on themselves.

There is no particular difficulty for evolution, or a species, here. If we look at the bio-chemistry of even simple life forms, like an amoeba for example, we can see that the apparent complexity of a system is no bar to evolution if-and-only-if the evolution of the system over time continues to secure and/or enhance the species' survivability.

The wheel is not particularly complex. It's merely that in order for a biological organism to exist, it requires energy and waste to be transported around. Inherent in the design of a wheel is that it spins. It spins around a center point. So, where do you connect the pathway where energy goes from the body to the wheel without it getting tangled up when the wheel spins?

It's not complexity, it's an engineering problem.

That may be why there are examples of very complex organisms, but no examples of organisms with wheels. It's not the complexity. It's a design barrier.

Maybe there would be a way to have, like, an organism roll on wheels, but energy and waste can move from the wheel unit to the body via some kind of osmosis. But, then you'd have a permeable membrane almost constantly exposed to the environment. Or, perhaps some form of symbiosis could form, where the wheel is a self sufficient entity that doesn't need food from the body. However, then the wheel would need its own way to get food intake and waste output.

You can't take veiny creatures, though, and put wheels on them because it would be like taking electrical wires and running them from the car engine to the wheel itself. As the wheel spins, the wires would get wrapped up around the axle and rip off.

There's no reason to think that a wheel on an organism has to work in the same manner as a wheel on a car. As you know, evolution doesn't work to a plan like that, and I've given the example of the human shoulder joint to highlight that this feature of hominid anatomy can produce articulated movement analogous to that of a wheel, although I have also pointed out that even given this evolution is driven by the interplay of environmental circumstance and the necessity of any such evolbed locomotive 'solution' having survivability benefits for any organism operating under those environmental conditions. My comments above were only intended to correct any lingering or implicit assumptions about the apparent functional necessity of 'hubs, axles and bearings' etc as being insurmountable constraints on, or barriers to, evolution.

I didn't say it had to work the same way as it does in a car, and in fact that's the whole problem.

And yet you did say...

Perhaps there is a difficulty in evolving a system of hubs, axles and bearings that can spin around without veins and nerves getting all twisted up on themselves.

... and ...

You can't take veiny creatures, though, and put wheels on them because it would be like taking electrical wires and running them from the car engine to the wheel itself. As the wheel spins, the wires would get wrapped up around the axle and rip off

... so I think my response is quite reasonable.

... It simply can't work the same way that it works on a car. The wheels on a car don't need to sustain themselves. A living wheel, like a living foot, has to receive food energy and get rid of waste.

A shoulder joint doesn't spin round like a wheel, so all the veins and sinew don't get tangled up.

Something I have pointed out myself. Nor am I saying that the proposed evolved wheel should or must be like a shoulder joint. The human shoulder joint is merely an example of an anatomical feature with the articulatory flexibility to describe a circle on a vertical plane. I have acknowledged that in order to do this the arm also has to rotate along its axis.

The fact is that for living wheel to work, it has to function. Of course it doesn't have to have wheel bearings and antilock brakes. But, it does have to spin around and round. So, you need to attach the wheel to the body, and get it food energy and remove waste matter from the cells. With all other aspects of the animal body, food energy goes to the limbs via long tubes, and other long strands go there for nerves and such. the very act of spinning like a wheel makes wheels extraordinarily more of an engineering problem for living creatures than legs. Evolution would have to come up with a different way to fed the wheel organ, and remove waste products.

None of which I have disputed, except that we have the example of a human shoulder joint to show how such a mechanism could get around the problem of maintaining circulatory and nervous systems etc.

Maybe, for example, the connection could disconnect when the animal is going to roll. That is, you'd have like veins meet at a valve connector when the wheel is stationary, so blood can go in and out. Then, when the creature is going to move, the connection shuts and the veins disconnect and then the wheel spins and then they reconnect when the animal stops.

Maybe there is an osmosis thing where the wheel just sort of oozes stuff in and out.

Actually fleshing this idea out (see what I did there!?) isn't necessary, but if one were to indulge in speculation one might imagine something like a shoulder joint connecting to something like an arm housed inside some additional anatomical wheel-like framework.

For some reason, no such organisms have ever evolved.

For some reason eh? What do you think that reason is, or might be now I've pointed out, and indeed you have agreed, that it isn't necessarily a bio-mechanical, anatomical limitation?

[Hermit]

I've given the example of the human shoulder joint to highlight that this feature of hominid anatomy can produce articulated movement analogous to that of a wheel

No, Brian.The shoulder joint does not produce movement analogous to that of a wheel. It enables the attached arm to swing rather than to rotate indefinitely. Sooner rather than later the arm will reach the limit of what little rotational limit it has. That is because the shoulder joint is not analogous to an axle. It is analogous to a hinge, Though the fact that this particular hinge can swing in more directions than one you find on a door on account of it being of the ball and socket design, it affords precious little rotational capability. If you want more rotational than it provides, you must interrupt the rotation, disengage from the action you are performing, sort of rewind, reengage and begin again. Repeat until the job at hand is done. That is what you do when you use a manual screwdriver or juice an orange.

I have acknowledged that in order to do this the arm also has to rotate along its axis.

Which is why the movement the shoulder joint enables is not analogous to that of a wheel.

[Brian Peacock]

I still you are taking me too literally, nonetheless the double-joint at the shoulder allows you to sit in a chair and describe a circle with your hand down, up and behind, with a twist past your ear, and then forward again.

Look, I'm saying that this is merely analogous to the arc described by a point on the circumference of a wheel, not a wheel equivalent, and I'm raising this only as an example to counter the possible misapprehension that no such evolutionary process would or could take place because of the bio-mechanical impossibility of maintaining circulatory and nervous systems.

In other words, the example here is meant to exemplify a broader idea, that whatever the locomotive, anatomical or bio-mechanical features organisms evolves they are in response to the prevailing environmental circumstances at each generational iteration of the genome, where accumulated phenotypical traits secure or enhance the survivability of not just the species members which express them but the species as a whole, and is not a process limited by some arbitrarily predetermined design or engineering constraints.

As I've said already, it's hard to imagine an environment where wheelish appendages might be beneficial to an organism, even, perhaps, a flat, relatively frictionless low gravity one.

[Hermit]

Yes, I got your message at least twice now. Still, the motion of the arm is not so much rotating as swinging and the ball and socket joint of the shoulder is nothing like an axle. The analogy to a wheel is too far fetched.

As for countering the possible misapprehension that no such evolutionary process would or could take place because of the bio-mechanical impossibility of maintaining circulatory and nervous systems, yes, someone might possibly entertain such a misapprehension, but so far nobody seems to in this thread, and I certainly don't either. You keep repeating yourself as if someone has.