The Vagus nerve in the Giraffe

[Dedeplease]

There is the the vagus nerve, in mammals, most animals have one, you have one, fish, frogs, birds, snakes exc all own this nerve. Basically its anerve that goes from your brain down around your aoritc loop (this is a loop of a main artery above your heart) and to your throat. The point of this nerve is to essentially connect your throat to your brain.





In fish, that makes it a short journey from brain to throat, in fish and sharks it’s often a straight line. As amphibians, reptiles and then mammals evolved, the nerve kept running through that loop, but the path from the brain to the throat now has to run down to the heart first (aortic loop, remember?).



So in humans, the nerve is more than twice as long as it would need to be if efficiently engineered, or if it hadn’t been moved by evolution.


Now here's the main thing, in giraffes, the vagus nerve is more than 15 feet long, typically, running from brain, down the neck, through the aortic loop (where it connects to nothing, of course), back up the neck, to the larynx. (I’m making a quick sketch here — it’s much more complex than that.)


The question for anti-evolutionists is why that nerve, connecting the brain to the throat, must run down to the heart. And the only answer is, it doesn’t, except that evolution has not found a way to stop it from looping through that artery in development. So the embryo develops the way ancestral embryoes did, right through that loop; and as some creatures grow to stand upright, on fours or twos, the looping becomes more loopy; it’s a vestige of our fishy ancestry.


Theres a million and one more reasons to support evolution, another would be that girraffs have 7 neck bones, which is the exact number all mammals have (as well as humans), the massive size of these bones causes all kinds of problems for the animal, including drinking and mating, of course more bones would be much much more efficent, but thats not how they evolved.

 

[shernren]

Of course it's been poorly designed, what do you expect from the vaguest nerve in the giraffe?

[you've been punned]

 

[juvenissun]

There is the the vagus nerve, in mammals, most animals have one, you have one, fish, frogs, birds, snakes exc all own this nerve. Basically its anerve that goes from your brain down around your aoritc loop (this is a loop of a main artery above your heart) and to your throat. The point of this nerve is to essentially connect your throat to your brain.

In fish, that makes it a short journey from brain to throat, in fish and sharks it’s often a straight line. As amphibians, reptiles and then mammals evolved, the nerve kept running through that loop, but the path from the brain to the throat now has to run down to the heart first (aortic loop, remember?).

So in humans, the nerve is more than twice as long as it would need to be if efficiently engineered, or if it hadn’t been moved by evolution.


Now here's the main thing, in giraffes, the vagus nerve is more than 15 feet long, typically, running from brain, down the neck, through the aortic loop (where it connects to nothing, of course), back up the neck, to the larynx. (I’m making a quick sketch here — it’s much more complex than that.)


The question for anti-evolutionists is why that nerve, connecting the brain to the throat, must run down to the heart. And the only answer is, it doesn’t, except that evolution has not found a way to stop it from looping through that artery in development. So the embryo develops the way ancestral embryoes did, right through that loop; and as some creatures grow to stand upright, on fours or twos, the looping becomes more loopy; it’s a vestige of our fishy ancestry.


Theres a million and one more reasons to support evolution, another would be that girraffs have 7 neck bones, which is the exact number all mammals have (as well as humans), the massive size of these bones causes all kinds of problems for the animal, including drinking and mating, of course more bones would be much much more efficent, but thats not how they evolved.

Everything you said above can also be used to against evolution. One simply see the same features from a different angle, then everything is turned around.

 

[Melethiel]

Not precisely. The left vagus nerve, aka Cranial nerve X - DOES have a loop that goes around the aorta - the recurrent laryngeal branch of the vagus. (Right vagus has the recurrent laryngeal loop a bit higher, around the subclavian artery). However, the vagus itself is not the "throat" nerve (although it does provide some of the sensory innervation to the throat)...it continues down along the heart and then the esophagus down into the abdomen, innervating stuff all the way down to the stomach, liver, and part of the intestines.

But nitpicking aside, that's why embryology is so much fun. Really traces out evolution (and helps us poor students studying anatomy to understand why some structures follow really weird paths).

 

[shernren]

On a more serious note, as much as I'm an evolutionist, I have to say the argument from bad design ("dysteleology", or something such) is hardly a strong argument against creationism. It's unfalsifiable in much the same way that the argument from good design is unfalsifiable: since within the ID framework, neither the Designer's design priorities nor his parametric phase space are empirically accessible to us, the notion of "good / bad design" is hardly falsifiable, much less quantifiable.

Have you ever watched Galaxy Quest? It's a fantastic movie, which includes some pretty potent ruminations on the nature of literary truth. In a climactic scene, the bad aliens have taken over the good aliens' ship and set off a self-destruct timer, and the only way to disable it is to do so manually at the very heart of the ship. The human heroes rush there, but to their horror there is too little time! The clock counts down 00:03, 00:02, 00:01 - but then it gets stuck there and the ship doesn't blow up. Hurrah!

If I stopped there you would characterise the self-destruct function as being "badly designed". Surely the function of a self-destruct mechanism is to, well, self-destruct a ship! A mechanism that fails to do so is faulty and malfunctioning. However, I haven't told you something (though you would know it if you've watched the movie): the good aliens actually built their starship in imitation of a human sci-fi show, and in that show the self-destruct countdown frequently reaches 00:01 only to be stopped in the nick of time by brave human action. Therefore, to the good aliens, the function of a self-destruct timer is to go down to 00:01 - and then stop. You see? The optimality of a design depends intimately on design priorities.

More generally, mismatches in design priorities give rise to most moments of incongruity in good-vs-evil films. There are many funny "Manuals for Evil Villains" online detailing the most common, yet almost never avoided, pitfalls that villains make in movies, like the classic: "My evil lair will not have ventilation shafts large enough for intrepid heroes to crawl around through to surprise me!" Man-sized ventilation shafts, reactor cores so unstable that a single well-aimed photon torpedo is enough to blow them up, putting so much of your life-force into a ring that you can't survive after it is destroyed, trusting that your henchman will be loyal enough to destroy even his son - that's all bad design from the villains' point of view. From the point of view of a scriptwriter, though, those are splendid design because they give only the illusion of security for the baddies.

If life truly is "designed" (and I mean that in the ID sense, not in the general sense of contingent providential teleology), nobody - not even IDists - have empirical access to the design priorities and parameter space. The Death Star was designed precisely to be blown up by a single Rebel pilot strong in the Force, but there's no way to prove that until George Lucas makes an editorial decision to show it happening. That's why ID is in a sense unfalsifiable: how can you say that anything is well-designed without knowing what is designed for?

"Ah," the canard will be raised, "but mainstream scientists have said time and time again that they have disproved ID. What is it now - is ID unfalsifiable or is it false?" Firstly I should say that it's hardly an appealing choice for IDists! More importantly, what mainstream scientists can falsify is ID plus auxiliary hypotheses. That is, whenever IDists assume some set of design priorities (as they must), mainstream science can show that this set of design priorities do not actually fit the designed object. (I can't show that the Death Star isn't well designed for some purpose; but I can show that it was pretty badly designed if you have Force-guided X-wings in mind.)

For example, when IDists say that the flagellum is designed because it is irreducibly complex, evolutionists can (and have) shown that this hypothesis must fail because the flagellum actually isn't irreducibly complex. What you have in mind is roughly the same concept: to an IDist who says that lifeforms are designed because they utilize resources efficiently, you have shown that this hypothesis fails because they don't actually (like a giraffe, for whom far more flexible body systems could have been designed).

The problem with this approach is that some auxiliary hypotheses are more worth targeting than others. The IC one is pretty worth evolutionists' while, for example, if only because IDists make a big fuss about it. (It's a horrible auxiliary hypothesis if you think about it for a second: the Apollo spacecraft was very intelligently designed and yet it has so many redundant systems that you couldn't possibly call it irreducibly complex.) A closely related one is "no new information" - again, this one is reasonably well-defined and IDists make so much noise about it that disproving it becomes kind of a turkey shoot for evolutionists.

However, fuzzy ones like "efficiency" or "effectiveness" are really hard to talk about.

Is the human eye well-designed (because it does its job pretty well)
or badly designed (because if you flipped the retinal structure around you could get rid of the blind spot)?

Is the giraffe's nervous system badly designed (because there's a direct shortcut which the nerve could take but didn't)
or well-designed (because hey, how close are humans to making a nerve in the first place)?

So no, I don't think dysteleological arguments are much good against creationism. They are pretty funky on their own, as good evidences for evolution, though!

 

[Assyrian]

Everything you said above can also be used to against evolution. One simply see the same features from a different angle, then everything is turned around.

No the argument can't be turned around, or at least any time I have see Creationists try, it has involved ignoring how evolution actually works. This is because evolution works through small modifications of earlier systems. However features that work perfectly well in an old system may not be the best layout in the new. By the time a feature becomes a problem, all evolution can do is to provide patches, rather than rebuild the whole system. For that you would need to go back to the drawing board. OK for a designer, by not for modification done on the fly.*



* or any other organism

 

[juvenissun]

No the argument can't be turned around, or at least any time I have see Creationists try, it has involved ignoring how evolution actually works. This is because evolution works through small modifications of earlier systems. However features that work perfectly well in an old system may not be the best layout in the new. By the time a feature becomes a problem, all evolution can do is to provide patches, rather than rebuild the whole system. For that you would need to go back to the drawing board. OK for a designer, by not for modification done on the fly.

There is no need to discuss the anatomical detail of a giraffe. The long neck of giraffe is clearly NOT a product of evolution. Do we have a fossil record which shows the lengthening of the neck? As far as I can see in a few minutes search, there is NONE.

On the other hand, how could we positively say that any anatomical feature of any animal is a "bad design"? Don't we also found quite many such bad designs in our body? Have we ever tried to improve any of such bad design on ourselves by any medical procedure so that our body function could be improved just a little bit? Has anyone tempered with any bad design at the genetic level?

God's design is always perfect. No matter how smart we think we are to criticize it.

 

[shernren]

The long neck of giraffe is clearly NOT a product of evolution. Do we have a fossil record which shows the lengthening of the neck? As far as I can see in a few minutes search, there is NONE.

It's kind of like looking at this strip:

and saying "Calvin didn't actually throw a snowball at Susie (these are just five random drawings)."

 

[Mallon]

The long neck of giraffe is clearly NOT a product of evolution. Do we have a fossil record which shows the lengthening of the neck? As far as I can see in a few minutes search, there is NONE.

We do have a fossil record for giraffes, including forms like Climacoceras, Canthumeryx, Paleomeryx, Palaeotragus, and Samotherium. Most of these are relatively short-necked genera, mind you, which suggests that the long neck evolved relatively quickly, sometime in the late Miocene. I predict that's where the first long-necked forms will show up. Giraffa is already around come the Pliocene.

 

[Assyrian]

There is no need to discuss the anatomical detail of a giraffe. The long neck of giraffe is clearly NOT a product of evolution. Do we have a fossil record which shows the lengthening of the neck? As far as I can see in a few minutes search, there is NONE.

We didn't have Tiktaalik until a few years ago, but fish evolved into tetrapods whether we had Tiktaalik or not.

On the other hand, how could we positively say that any anatomical feature of any animal is a "bad design"? Don't we also found quite many such bad designs in our body? Have we ever tried to improve any of such bad design on ourselves by any medical procedure so that our body function could be improved just a little bit?

I had my appendix out, wear glasses and take Vitamin C when I have a cold, does that count?

Has anyone tempered with any bad design at the genetic level?

When they do, I want to be able to bend space and time.

God's design is always perfect. No matter how smart we think we are to criticize it.

Except of course when Creationists explain all the problems by saying how fallen we are.

 

[cerad]

The vagus nerve is also quite useful as a connection point for government implanted behavior control chips. The surgery is much easier to preform as opposed to implanting the chip in the brain.

 

[peteos]

Have to agree with Shemren, saying something is a "poor design" is subjective, unfalsifiable, and probably will do little convince those who don't understand common descent. Better to highlight not that it is "good" or "bad" but that it is quite clearly the result of an evolutionary history by examining the development of the features over time through viewing related species, fossils, and by examining embrology.

I was going to write more but having reread Shemren's post I see he covered everything I wanted to say with much more elegance. So everyone go reread Shemren's second post.

 

[juvenissun]

We do have a fossil record for giraffes, including forms like Climacoceras, Canthumeryx, Paleomeryx, Palaeotragus, and Samotherium. Most of these are relatively short-necked genera, mind you, which suggests that the long neck evolved relatively quickly, sometime in the late Miocene. I predict that's where the first long-necked forms will show up. Giraffa is already around come the Pliocene.

Yes, in my short search, I did read that people "have to" assume the neck lengthened "rapidly". But I don't think anyone could explain this fact.

By the way, what about the long neck giant dinosaurs both on land and in water (names?)? What is the reason for their long necks? The giant on land probably does not need any long neck to reach their favorite leaf. And a long neck in water seems to be a very bad idea.

 

[Critias]

It's kind of like looking at this strip:

and saying "Calvin didn't actually throw a snowball at Susie (these are just five random drawings)."

He didn't throw the snowball "at" Susie.. I think you should look a bit more closely at the picture. He tossed it to roll at Susie, hence the bigger ball when it hits her.

Those little details can get you every time.

 

[Mallon]

Yes, in my short search, I did read that people "have to" assume the neck lengthened "rapidly". But I don't think anyone could explain this fact.

Here's one explanation:
http://pandasthumb.org/archives/2007/05/now-thats-a-str.html
There are others out there. You've got access to the scientific literature, juvie -- check it out for yourself!

By the way, what about the long neck giant dinosaurs both on land and in water (names?)?

Sauropods and plesiosaurs.

What is the reason for their long necks?

Several reasons have been proposed, including facilitated browsing/bottom-feeding, sexual selection, as a counter-balance for the long tail, etc. Some suggestions are more likely than others, of course.

The giant on land probably does not need any long neck to reach their favorite leaf.

Yes, they would.

And a long neck in water seems to be a very bad idea.

Interesting to hear this coming from a neocreationist.
Why would a long neck in the water be a bad idea?

 

[Assyrian]

He didn't throw the snowball "at" Susie.. I think you should look a bit more closely at the picture. He tossed it to roll at Susie, hence the bigger ball when it hits her.

Those little details can get you every time.

That is pure conjecture. There is no evidence of the ball growing in size or that the ball Calvin dropped was even the same ball that hit Susie. They just happen to be in separate frames the same cartoon. The enormous size difference proves they are not. Your theory contradicts the law of conservation of mass. If they are the same snowball then the extra snow was clearly created.

 

[shernren]

He didn't throw the snowball "at" Susie.. I think you should look a bit more closely at the picture. He tossed it to roll at Susie, hence the bigger ball when it hits her.

Those little details can get you every time.

Oof. Of course, I've never thrown a snowball before. I'm hardly educated in the intricacies of offensive icethrowing.

 

[juvenissun]

Interesting to hear this coming from a neocreationist.
Why would a long neck in the water be a bad idea?

snapped very easily?

 

[juvenissun]

That is pure conjecture. There is no evidence of the ball growing in size or that the ball Calvin dropped was even the same ball that hit Susie. They just happen to be in separate frames the same cartoon. The enormous size difference proves they are not. Your theory contradicts the law of conservation of mass. If they are the same snowball then the extra snow was clearly created.

Hey, welcome to YEC, Assyrian.

 

[Mallon]

snapped very easily?

Ok, but seriously, why do you think a long neck is poorly suited for underwater living?