You are actually bringing this up again?
Dawkins is an evolutionist hack. In his demonstration of the poor design of the giraffe's RLN he 'hacked' right through the evidence of ID that has been observed by others
This is hilarious.
Creationists ALWAYS do this - they merely declare this or that to be DESIGNED! Let us take a look at these sad creationist claims...
, including "Gray's Anatomy", which states this about that:
"Indeed, hints of important functions for the RLN nerve can be seen in the old authority, Gray's Anatomy, which states regarding the normal human design:
As the recurrent nerve hooks around the subclavian artery or aorta, it gives off several cardiac filaments to the deep part of the cardiac plexus. As it ascends in the neck it gives off branches, more numerous on the left than on the right side, to the mucous membrane and muscular coat of the esophagus; branches to the mucous membrane and muscular fibers of the trachea; and some pharyngeal filaments to the Constrictor pharyngis inferior.
So it seems that the RLN is innervating a lot more than just the larynx.
LOL!
Wow, OK.. Amazing "insight".... What of it?
Amazingly, Luskin the creationist lawyer actually should know that the RLN is a branch off of the Vagus nerve, since he paraphrased the branching and subsequent branching of the RLN nerve to provide some fibers to the cardiac plexus (surely you know what a plexus is, right champ?) from some other source. The obvious issue is this - why didn't those branches just come off of the Vagus itself if that link was so important?
I explained why the route of the RLN is the way it is way back when you made those grade-school-level claims about the gut and the aorta sending motor fibers to the larynx - guess you forgot all that.
Pro-ID biologist Wolf-Ekkehard Lönnig,
Wolfy the plant breeding researcher? That one?
in his article "The Laryngeal Nerve of the Giraffe: Does it Prove Evolution?," quotes a passage from a much more recent 1980 edition of Gray's Anatomy stating much the same thing:
As the recurrent laryngeal nerve curves around the subclavian artery or the arch of aorta, it gives several cardiac filaments to the deep part of the cardiac plexus. As it ascends in the neck it gives off branches, more numerous on the left than on the right side, to the mucous membrane and muscular coat of the oesophagus; branches to the mucous membrane and muscular fibers of the trachea and some filaments to the inferior constrictor [Constrictor pharyngis inferior]. "
(Gray's Anatomy, 1980, p. 1081, similarly also in the 40th edition of 2008, pp. 459, 588/589)
The Recurrent Laryngeal Nerve Does Not Refute Intelligent Design
Rather than being poor design it seems rather elegant to me.
Wow - 2 quotes saying the same things from the same source about some branches off the RLN and you pronounce it all Designed? Wow. Pretty low standards for ID evidence, what a coincidence.
I do wonder if Luskin the lawyer or Wolfy the plant creationist wondered why those other branches needed to travel in the RLN in the first place? Other parts of the vagus run much closer to those targets than the RLN in the adult.
So, in the giraffe, rather than traveling that extra 15 feet or whatever it is, the 'several cardiac filaments to the deep part of the cardiac plexus...to the mucous membrane and muscular coat of the oesophagus...to the mucous membrane and muscular fibers of the trachea and some filaments to the inferior constrictor' those targets could have been innervated by fibers only having to travel inches in most cases.
Much more efficient.
Funny thing - when you brought this all up a few months back, I quoted - and linked to - Gray's as well. And darned if you just ignored it all in favor of some dopey health guru website and such. Funny how that works with creationists...
Anyway - you won't learn this from the goofy Luskin or Wolfy the plant biologist, but the actual reason the RLN takes the path it does - and why I explained this to you before - is that in the embryo, when these nerve pathways are first established, the parts innervated by the vagus are much, much closer to the source of the nerves (the brainstem, for the most part). This is also why the phrenic nerve takes the path it does - the bulk of the thoracic organs (e.g., heart) and the gut are right "underneath" the brainstem and so the pioneer axons travel basically straight 'down' to the heart, larynx, etc. But to get there, they have to go through the developing arterial system, right between the aortic arches. Then, as development proceeds, some of the arches are resorbed, some co-opted to form parts of other structures, some retained as-is. Most of the targets of that early innervation migrate (relative to their original position), 'pulling' their innervation along with them. But the branch of the Vagus that forms the RLN goes between 2 aortic arches, one of which does NOT regress or get co-opted, but remains intact, and so the RLN travels and lengthens along with that arch, down into the upper thorax.
THAT is why the RLN takes the route it does.
Not 'design', but by virtue of a developmental leftover, one we see in ALL terrestrial vertebrates to some extent, certainly in all mammals.
And this is actually strong evidence for either the very limited abilities and short-sighted work of a tribal deity from the middle east, or for the unity of development resulting from common ancestor.
