Unintelligent design (recurrent laryngeal nerve)

Why isn't it sufficient? If "good enough" works then why must "perfect" eventually come about?

That this trait is in the population is true, but at the moment I don't think there is any evidence of this necessarily being a genetic trait and therefore 'readily available'. Development is a complicated process and some phenotypic variations arise simply through environmental or purely stochastic causes.The existence of those with non-recurrent laryngeal nerves is contrary to Big_Al's claims, but without a clear genetic basis it doesn't provide support for your claim that if it was more efficient it should have risen to predominance in the human population. Even with a clear genetic basis your argument would still be tenuous, it would be hard to quantify the fitness benefits of such a change in a human population.TTFN,WK

No, I told a truth. Coyote is the untruthful one. (I hope you understand what I'm trying to convey, we can both be elephant hurling. It won't add anything to nay discussion)

Making a few extra feet of nerve fiber for no other reason than to create a longer route is less effecient. Designer flunks.

So you now agree that the recurrent route is less efficient, if there exists no other reason. And so you should also agree that natural selection should have favored the direct route.

This assumes that evolving the direct route would not require a drop in fitness. If that assumption is wrong then so is your conclusion. Embryonic development is a very fickle beast.

Those of us in the population right now with a direct did not experience a drop if fitness, I think.

It would require numerous changes in embryonic development that would result in lowered fitness. A designer would not have these problems to deal with.

So evolution produced all the biological complexity we see, but it couldn't possibly reroute a nerve ? Because of reduced fitness in initial stages ??Besides, this theoretical approach is irrelevant since those that have a direct route haven't experienced this 'lowered fitness' you are talking about. this leaves only Wounded King's concern that the trait maybe isn't genetic.Edited by slevesque, : No reason given.

Do you mean in the same way that natural selection should have decreased back pain, improved eyesight, removed the need to breath, bestowed telepathy, etc, etc. Natural selection selects what is sufficient, what is good enough - not some idealised wish-list. The RLN is good *enough*. Its route makes complete sense within an evolutionary paradigm - its lack of re-routing makes complete sense within an evolutionary paradigm. Design has no explanation whatsoever. You can't blame this one on The Fall...

Maybe you could show us some of this evidence. Starting with the recurrent laryngeal nerve.

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Facts don't lie or have an agenda. Facts are just facts

No not at all. However, if any of these were to be already present in the human population, I would expect natural selection to select for them. The same way it should/should have selected for a direct route for the laryngeal nerve, since it is present.This is different from wishful thinking of traits that are absent.

It's nothing of having a direction towards perfection. But it's logical to expect that natural selection fixes the best traits available.It's like a grey fly in a white environment. Sure it's 'good enough', but if suddenly some of them become white, you expect the population to eventually go white via natural selection. Suddenly, when the white arrives, grey isn't really ''good enough'', it is eventually replaced by a better option.If truely this option is better. It's contrary is also true: if the other option is filtered out of the population instead of being fixed by natural selection, it most probably means that it is worst then the first one, even though sometimes it seems counter-intuitive.

But it's logical to expect that natural selection fixes the best traits available.

Yes in the long long long run, but what if the best traits available are the "good enough" traits? Once the RNL is "good enough" what would cause it to become "perfect" or even "slightly better than good enough"?Edited by DrJones*, : No reason given.

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It's not enough to bash in heads, you've got to bash in minds
soon I discovered that this rock thing was true
Jerry Lee Lewis was the devil
Jesus was an architect previous to his career as a prophet
All of a sudden i found myself in love with the world
And so there was only one thing I could do
Was ding a ding dang my dang along ling long - Jesus Built my Hotrod Ministry
Live every week like it's Shark Week! - Tracey Jordan
Just a monkey in a long line of kings. - Matthew Good
If "elitist" just means "not the dumbest motherfucker in the room", I'll be an elitist! - Get Your War On
*not an actual doctor

Agreed. There is no clear genetic basis. Is there any way we could find this out ? Of course, the next question would be: is it 'visible' enough for natural selection to select it ?If not, I think it brings up certain problems for natural seleciton as a true 'driving force'. I mean, a rerouted nerve is a pretty ''big'' change in an organism and if natural selection cannot even select such a difference, maybe we should question the underlying mechanism.Because sometimes evolutionnists talk about NS as if it could detect and select even the smallest of changes in organisms. But of course I think, and it is a major underlying principle of Sanford's book, that natural selection is blind to almost all mutations except those few that have a detectable phenotypic effect. The other vast majority of mutations go through fixation via genetic drift; randomness.But this is quickly getting off-topic (which is bound to happen frequently with such a restricted subject)

When the ''slightly better than good enough'' mutation would arise in the population.

Ok, so I think everything that could be said has been said, the rest would only be the same repeated things for my part. So I'll give my conclusionThe argument in the OP can be written in this manner:If life was intelligently designed, we should not find examples of bad design in nature
we find examples of bad design in nature
therefore life was not intelligently designedWhich is a correct syllogism, denying the consequentHowever, the issue is to prove the second premise (the first being true)The Reccurent Laryngeal nerve has not been shown to be well designed
therefore it is a bad design
therefore a bad design exists in natureWhich is, as I have said, an argument from ignorance. It is of the same form as the Behe argument:An irreducibly complex system (ICS) has not been shown to be able to evolve in a step-by-step fashion
therefore, an ICS cannot evolve in a step-by-step fashionWhich I have always viewed as an argument from ignorance. (I know Behe has since develeopped his argument, but I haven't kept up with it so I don't know if he got it out of the fallacy. This form of the argument is the original as can be found in ''Darwin's black box''.)Since this is a logical fallacy, the second premise remains unproven, and so the conclusion also remains unproven.I will finally add that holding on to that argument is anti-scientific. If you have already concluded that the RLN route has no function, you won't search for it. And if you don't search for it, you are unlikely to ever discover it if it does exist. The nature of science is to never think we know enough about a given thing as to conclude it a closed subject. It is the very driving force of science to always think there is more to discover then we know. In the case of the RLN, it means trying to find out why would evolution have maintained this counter-intuitive route for all those millions of years, despite a more direct route being available.

Hi Slevesque, You are missing out half the argument. We have an evolutionary explanation for the route of the RLN. I outlined it for you in Message 37 and you completely ignored it. Now you are ignoring it again.

quote:

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The basic version is that the RLN is a branch of the vagus nerve, the fourth branch. Now trace our evolution back as far as fish and this branch took a path between the gill arches. This took it back behind the sixth gill arch. This is what we see in modern fish.

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Now in a fish this isn't a problem. The gill arches are close together and the nerve only covers a short distance - it all lines up, with each nerve branch going through each gill slit in turn. The problem is that in mammals, the "sixth gill arch" is homologous to and has evolved into the ductus arteriosus, a small channel that allows the blood in a developing foetus to bypass the lungs (this duct closes up soon after birth - usually). The RLN has to go around this. That's why it must take so torturous a route around the aortic arch.

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Now this makes sense from an evolutionary perspective. If the fourth vagus branch originally went around the far side of the sixth gill arch, then the modern RLN must do the same with regards to the ductus arteriosus. Why? Because one thing that evolution absolutely cannot do is evolve through a stage which, though might have a beneficial effect in a million years time, is lethal in the short term.

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It is not simply a matter appealing to ignorance; we have an extremely robust explanation for the RLN. You want us to cast that aside. In fact, you want to cast it aside in favour of no explanation at all. Then you have the nerve to accuse others of being anti-science.The RLN is a very good fit for evolution and we have a thorough understanding of how it came to arise. The RLN is a very poor fit for creationism and you have no explanation beyond "Oh well, I'm sure something will turn up." Perhaps you would after all prefer ignorance to knowledge that challenges your beliefs.Mutate and Survive

Please show that in the giraffe the reworking of the development of the entire ennervation of the neck would not require a drop in fitness. Evolution produces complexity that is good enough, not brilliant designs. The RLN is good enough, but rather poor design if ID is true.

In the evolution of the giraffe, the best trait is a long neck and the RLN be damned.