What About . . . Giraffes Laryngeal Nerve?

Maybe you’ve heard Richard Dawkins or his minions claim that the Giraffe’s Laryngeal nerve proves evolution.  Let’s deal with it!
I’ve been using the amazing design features found in a giraffe as wonderful evidence for a Creator.  So, you can imagine how I felt when I heard someone use the giraffe as an  argument that supposedly proved that life has evolved.  
Instead of me trying to explain their argument, we’ll let you watch it for yourself.
Laryngeal Nerve
So, does that mean evolution must be true?  Not so fast, let me introduce you to Dr. David Dewitt.  By the way, he’s a Creationist and he has a “real” PhD!  Don’t let anyone tell you that you can’t be a “real” scientist and believe in Creation.
He’s a biochemist, neuroscientist, head of the science department at Liberty University and a long time friend.  Because of his unique qualifications we asked him to give an answer to this supposed “evidence” for evolution.  Thanks in advance to Dr. Dewitt.  By the way, you really should read his excellent book, Unraveling the Origins Controversy.  I read materials on the creation/evolution issue a LOT and, truth be told, his is one of the very few books that I actually finished!  That’s how good it is.  In addition, we have it on sale at the moment in the rforh store.
Anyway, here’s Dr. DeWitt’s answer:
Jerry Coyne, in “Why Evolution is True” uses several examples that are “only explicable by evolution”.  He specifically mocks the laryngeal nerve and the circuitous route that it must take to get to the larynx.  Instead of going straight, it goes down, loops under the aorta and then goes back up.  It is an example of “poor design”.  Richard Dawkins also criticizes the same nerve and how poorly designed it is.
First of all, the vagus, or tenth cranial nerve is coming from the medulla (or brainstem), which puts it behind the trachea (windpipe).  If it branched off early, it would have to go around the trachea to get to the front so that it could innervate the voicebox.  This may not be as easy as it sounds.
Second, remember there are only 12 pairs of nerves coming out of the central nervous system.  The vagus nerve splits off in various locations where it innervates several different tissues.  One of these branches is the laryngeal nerve.  Some of the branches from this nerve are responsible for heart rate and parastalsis so a large portion of the neurons need to go down to the heart and viscera anyway.  Most likely, there is a good developmental neurobiological reason that this is a preferred route for innervations.  Neurons like to grow together in bundles and do so as much as possible.  It actually helps them to grow faster than they can individually.
When giving directions to my house, I don’t give the shortest route, which is the way that I take.  I have people come another way that has fewer turns and better landmarks.  Sometimes the easiest way to get somewhere is not the shortest way.  Getting nerves to find their targets is a very complicated process involving large numbers of different proteins.  Linking nerves to targets involves getting the nerve out of the central nervous system, guiding it along a path, branching at certain points and then finding the target.  Since the nerve gets to the larynx, it is guided on this pathway.  No doubt it is the most efficient.
Compare it to providing electrical wiring or plumbing to several fixtures in a house that is already built.  (This is appropriate because the neurons are connecting to targets that are already in place and they grow through tissue to get there)
While there may be a more direct route for the additional fixtures, it would actually be more difficult to get to them if you have to send a separate line.  Instead of running it along the same path that others are going on and then adding an extension, you would have to produce an additional, separate path.
Here is an example, imagine a single story house that did not have a washing machine when it was built, it was put in later.  Water lines from the hot water heater go down into the crawl space and then across the bathroom, hooking up the bathroom sink and shower, and then cutting across to the kitchen sink.  (Notice the pipes run down the hot water heater and under the floor and then come up to the faucets.  This is not direct, but it looks better and still works fine.)
Now the washer gets put in and it is on the other side of the wall from the hot water heater but in the opposite direction from the bathroom.  While it would be possible to have about two feet of pipe to connect the hot water heater to the washer, this is not what the builder does.  Instead, he goes under the crawlspace and adds a long pipe coming off the line from the bathroom sink.  Therefore the water goes from the hot water heater, under the floor toward the bathroom and away from the washer, then back toward the washer and up the wall to the hose for the washer.
So look, the hot water goes in the wrong direction before going to the washer!  Why?  1) There is only one outlet for hot water out of the hot water heater.  You can’t add another.  In the same way, there are only 12 cranial nerves.  You can’t send any others out of the brain.  2)  It is easier because you can cut out the small piece of pipe to the bathroom sink and replace it with pipe that has a split to go to the hot water.  While you could run a more direct pipe, if you did, it would be harder to install.
What Coyne and Dawkins are asking for is for a separate, direct line to go to the larynx when it appears more expedient developmentally, to have those neurons run the circuitous route.  Neurons grow best when they grow in a bundle of many different fibers and then branch off separately.  It is a developmental issue, which is different from a design issue.
If it doesn’t affect function or appearance, an installer is going to do what is easiest.  The customer might come along and say, why didn’t you do it in a more direct route?  The installer says, “I’m sorry, did you want to pay 3 times as much for labor?”
David A. DeWitt, Ph.D.
Professor and Chair 
Biology & Chemistry
If you would like further information on this issue here are two more good articles for you to check out.
1.  That Troubling Laryngeal Nerve?, Frank Sherwin, ICR.
2.  Recurrent laryngeal nerve, Jonathan Sarfati, Creation Ministries International
 
We pray this material helps you.  Thanks again for your prayers and your support.
Stay bold,
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