Why didn't animals evolve wheels?

[Seth]

Seth wrote:

So far as you are aware. But remember, neither you nor "science" knows everything about everything and "available evidence" inherently means that there is, or may be evidence that is NOT available to you, or to science today, but which may come to light some time in the future. The absence of evidence is not evidence of absence, a concept that you seem to have great intellectual difficulty integrating.

Way to go, Captain Obvious...

Science is always prepared (unlike most religions) to modify its view of the universe as new evidence come to light.

Yes, it is, which is why you are purveying religion-based pseudo-science here.

The statement that, in theory, there is a chance that a highly speculative intervention by aliens in Earths past genetic history does not mean that we abandon the current model, which parsimoniously explains all the evidence available. Simply, science can ignore such fantasies unless and until dramatic new evidence comes to light...

Strawman argument.

Why don't you simply and clearly admit that it is scientifically possible that intelligent design could have occurred to organisms on earth sometime in the past? I'll even grant your skeptical proviso, but you keep trying to evade admitting the truth, which is unbecoming sophistry.

Is it scientifically possible that at some time in the past, an intelligent agent manipulated the DNA of organisms on Earth? Yes or no.

[JimC]

Is it scientifically possible that all the supernovae observed and analysed by astronomers over the years were caused by meddling aliens with advanced technology who like making stars go bang?

Can't rule it out, by your version of logic...

Should astronomers make allowance for such an absurd but impossible to rule out possibility?

Fuck no...

[rainbow]

Should astronomers make allowance for such an absurd but impossible to rule out possibility?

Of course.

Have you not read Douglas Adams?

In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.

[Brian Peacock]

Seth wrote:

It shows, again, that it is possible that such manipulation occurred.

No, it doesn't. It merely shows that low level manipulation by scientists is possible now. Life on Earth clearly arose through processes of natural evolution, as shown by all the available evidence.

Indeed, this is just how science works. It's not an endeavour concerned with objective truth but workable predictive models that most fully account for all the available information. The models that comprise the Theory of Evolution are the most parsimonious explanations of the natural systems involved given the information we have gathered so far. There's no reason to ignore them, or to place assumptions and blind assertions about possible (not to mention completely unevidenced) explanations on a equal footing, and if there are reasons to dispute them then that simply requires the demonstration of more parsimonious explanations for what is actually observed. All that is needed here is an rational mind and a diligent approach to data gathering, which is something that has not only led to robust, testable hypotheses and the developments of workable theories, but as this is an ongoing process it also means that when new information becomes available current models can be revised and better models can be developed.

The Theory of Evolution is not something people simply imagine to be true and then go out to find the evidence for it, throwing away anything that doesn't match the imagined objective (like creationists do for example), it is a developing rational theory which accounts for and explains everything we have observed in the biological realm so far.

As to the possibility that the entire bio-chemical matrix of the biosphere was intelligently designed in such a way that evolution only appears to be an entirely natural unguided process without an ultimate goal or end when in fact it isn't - well that's a completely unfalsifiable claim and can be safely ignored as such: we have no need of that hypothesis, to paraphrase Laplace. But even if it were true it still does not change a single thing about what we actually do know about the natural processes at play.

[Seth]

Is it scientifically possible that all the supernovae observed and analysed by astronomers over the years were caused by meddling aliens with advanced technology who like making stars go bang?

Can't rule it out, by your version of logic...

Should astronomers make allowance for such an absurd but impossible to rule out possibility?

Fuck no...

You just can't bring yourself to admit a simple truth, can you? You have to resort to hyperbole, bluster, evasion, insult and otherwise slide around the truth because it conflicts with your Atheist/Science religious orthodoxy, which becomes more and more obvious with every evasive post you make.

Just admit the truth. Go ahead, say it. It's easy...only one word is required. Three little letters: "Yes."

[Seth]

Indeed, this is just how science works. It's not an endeavour concerned with objective truth but workable predictive models that most fully account for all the available information.

What the HELL are you talking about? Science USES workable predictive models in the quest to find and prove objective truth. You are saying essentially that scientists are free to ignore objective truths in favor of hypothetical truths merely because they have constructed a model that appears to give them the answers they want. While that is absolutely true of global warming research, which is not science, it is not true of actual science.

The models that comprise the Theory of Evolution are the most parsimonious explanations of the natural systems involved given the information we have gathered so far.

Yes, they are, but as I told you before, and as you studiously ignored before, the "law of parsimony" is not a law at all, it's merely a convenient invocation of Ockham's Razor, which merely SUGGESTS that the simplest answer is usually the correct one. But it should be obvious to you that this is not a law of physics or biology, it's just a guideline.

There's no reason to ignore them,

Strawman. I've never claimed there was.

or to place assumptions and blind assertions about possible (not to mention completely unevidenced) explanations on a equal footing,

Strawman. Nor did I insist on "equal footing." All I've done is to state an objective scientific fact and asked you to simply acknowledge it as an objective scientific fact.

and if there are reasons to dispute them then that simply requires the demonstration of more parsimonious explanations for what is actually observed.

I'm going to have to label this as the "Fallacy of Parsimony," in which the proponent of the argument insists that the simplest explanation is always the correct one in response to a claim that a more complex explanation better proves the case. It's a fallacy because while parsimony is a useful tool in scientific investigations, it is not a physical law of nature, it is merely a tool.

All that is needed here is an rational mind and a diligent approach to data gathering, which is something that has not only led to robust, testable hypotheses and the developments of workable theories, but as this is an ongoing process it also means that when new information becomes available current models can be revised and better models can be developed.

And a "diligent approach to data gathering" should include searching for data that disproves the hypothesis as well as that which supports it. As in the case of so-called climate scientists ignoring the nearly two-decade long "hiatus" in global temperature rise because it would conflict with their predetermined conclusions.

The Theory of Evolution is not something people simply imagine to be true and then go out to find the evidence for it, throwing away anything that doesn't match the imagined objective (like creationists do for example), it is a developing rational theory which accounts for and explains everything we have observed in the biological realm so far.

Actually, I think you largely wrong and that the theory of evolution (in non-caps) has become a religious scientific orthodoxy in which people do indeed throw away anything that might conflict with that orthodoxy, like the possibility of genetic manipulation of life on earth in the deep past.

As to the possibility that the entire bio-chemical matrix of the biosphere was intelligently designed in such a way that evolution only appears to be an entirely natural unguided process without an ultimate goal or end when in fact it isn't - well that's a completely unfalsifiable claim and can be safely ignored as such: we have no need of that hypothesis, to paraphrase Laplace. But even if it were true it still does not change a single thing about what we actually do know about the natural processes at play.

You really are piling on the straw today. You are falsifying the argument by moving the goalposts to suggest that my argument involves "the entire bio-chemical matrix of the biosphere" being intelligently designed. This is both mendacious and intellectually bankrupt and goes to show that you too suffer from an irrational religious bias.

[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.

[JimC]

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.

That was indeed one of my listed possible reasons earlier in the thread...

[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.

[JimC]

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.

In this case I will have to disagree. Biochemical and physiological complexity is immense, with a vast array of possibilities, and only few constraints. At higher levels (organs, for example), there is still an enormous number of possibilities, but there are also some important mechanical barriers. In this case, I am fairly certain that the mechanical barrier mentioned by Forty Two is real. Such a barrier need not mean that overcoming it is absolutely impossible, but it may require so many steps that the drunkard's walk of evolution never reaches that very distant selective hill.

[Brian Peacock]

That's basically what i was saying, only pointing out that the complexity of the system itself isn't a barrier, just that the evolving system must provide some benefit (or at least no limitation) in terms of survivability up the generational chain. Under certain environmental conditions wheels might be the most elegant, survival enhancing system of locomotion, it's just not that likely on Earth though.

[JimC]

That's basically what i was saying, only pointing out that the complexity of the system itself isn't a barrier, just that the evolving system must provide some benefit (or at least no limitation) in terms of survivability up the generational chain. Under certain environmental conditions wheels might be the most elegant, survival enhancing system of locomotion, it's just not that likely on Earth though.

Sometimes, when a certain basic structure has arisen which virtually all creatures in a given environment share, it may simply lead to some built-in constraints. For example, after the land-dwelling tetrapod body plan (or, to be esoteric, the German bauplan) came to dominate, there was virtually no chance of hexapodal mammals evolving.

In a similar way, once an internal system of nerves and blood vessels dominated (much earlier, of course, than the quadruped hegemony), then the possibility of a powered, rotating locomotor organ became extremely remote indeed, due to the structural limitations alluded to by Forty Two. So, to have a circumstance where "wheels might be the most elegant, survival enhancing system of locomotion", even given a suitable smooth environment, you would need to start with a rather different bauplan...

It's like the old Irish Joke: "You can't get there from here..."

[pErvinalia]

Wheels are really good for moving around. So why legs, even in the insect kingdom....?

Coz then it would have had to evolve bearings, axle (stubs, at least), brakes, suspension and maybe even a diff. It would also require a shitload more bone than a leg does. Pretty good reasons, I reckon.

[Brian Peacock]

Hola rEv.

That's basically what i was saying, only pointing out that the complexity of the system itself isn't a barrier, just that the evolving system must provide some benefit (or at least no limitation) in terms of survivability up the generational chain. Under certain environmental conditions wheels might be the most elegant, survival enhancing system of locomotion, it's just not that likely on Earth though.

Sometimes, when a certain basic structure has arisen which virtually all creatures in a given environment share, it may simply lead to some built-in constraints. For example, after the land-dwelling tetrapod body plan (or, to be esoteric, the German bauplan) came to dominate, there was virtually no chance of hexapodal mammals evolving.

In a similar way, once an internal system of nerves and blood vessels dominated (much earlier, of course, than the quadruped hegemony), then the possibility of a powered, rotating locomotor organ became extremely remote indeed, due to the structural limitations alluded to by Forty Two. So, to have a circumstance where "wheels might be the most elegant, survival enhancing system of locomotion", even given a suitable smooth environment, you would need to start with a rather different bauplan...

It's like the old Irish Joke: "You can't get there from here..."

Well, there's nothing to disagree with there, but (ha!) if one thinks about the free-floating joint of the human shoulder, for example, which can rotate the arm on a vertical plane, then perhaps one can admit that some sort of Filozoic wheel is at least possible, even while highly unlikely - in our case it requiring n-number of evolutionary stages from an arm-elbow-wrist-hand-fingers configuration to some sort of wheel analogue and where each stage produces a net survivability benefit strong enough to drive reproductive selection. It's hard to imagine an environment where that would be beneficial though. Perhaps a low gravity flatland?

[Hermit]

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.