Evidence for Evolutionism #1. The recurrent laryngeal nerve.

Long-Necked-Giraffes

In a comment on Tim’s post The Ludicrous Claims of Evolution! Why not ESP? Kiwi Dave says

Our recurrent laryngeal nerve inefficiently loops round our hearts instead of directly connecting to the brain stem; this, like cleft palates are a consequence of our fish ancestry.

I plan to post evidence for Evolutionism as I find it, to balance my pro-Creationist rants.

This is the first piece of evidence I’ve found worth posting.

recurrent-laryngeal-nerve-3201

The recurrent laryngeal nerve is a branch of the vagus nerve (tenth cranial nerve) that supplies motor function and sensation to the larynx (voice box). It branches from the vagus nerve in the chest cavity before it loops around the aorta and then back up to the larynx. Why doesn’t it take a more direct route? That it takes this circuitous detour is cited as evidence of evolution.

The extreme detour of this nerve (about 15 feet in the case of giraffes) is cited as evidence of evolution as opposed to intelligent design. The nerve’s route would have been direct in the fish-like ancestors of modern tetrapods, traveling from the brain, past the heart, to the gills (as it does in modern fish). Over the course of evolution, as the neck extended and the heart became lower in the body, the laryngeal nerve was caught on the wrong side of the heart. Natural selection gradually lengthened the nerve by tiny increments to accommodate, resulting in the circuitous route now observed.

giraffe recurrent laryngeal nerve

If we (and the giraffes) did indeed evolve from fish, then the course of the recurrent laryngeal nerve has a simple explanation. Its course is less simple to explain if we (and the giraffes) are products of special creation. Thus, the course of the recurrent laryngeal nerve is not merely evidence of evolutionism, but evidence for evolutionism.

I have a question. How difficult would it be to genetically re-engineer a giraffe (or a human) so that the recurrent laryngeal nerve passes directly from the brain to the larynx?

This entry was posted in Evolutionism, Fish, Giraffes, Intelligent Design. Bookmark the permalink.

22 Responses to Evidence for Evolutionism #1. The recurrent laryngeal nerve.

  1. Luke H says:

    The path of the vas deferens is a similar example of a convoluted route that formed over time. http://en.wikipedia.org/wiki/File:Route_of_vas_deferens_en.svg

  2. Tim says:

    Recurrent Laryngeal Nerve Is Not Evidence of Poor Design
    by Jerry Bergman, Ph.D. *

    http://www.icr.org/article/5512/

    • Steve says:

      I read it. Amazing jiberish.Not a good defense for creationism.

      • Richard says:

        “The most logical reason is that the RLN design is due to developmental constraints. ”

        What’s wrong with the above claim?

      • Bill says:

        I thing you may be lying about reading said article or you would have referenced the following highly authoritative, logical, and well-reasoned excerpt:

        Eminent embryologist Professor Erich Blechschmidt wrote that the recurrent laryngeal nerve’s seemingly poor design in adults is due to the “necessary consequences of developmental dynamics,” not historical carryovers from evolution.3

        Human-designed devices, such as radios and computers, do not need to function until their assembly is complete. By contrast, living organisms must function to a high degree in order to thrive during every developmental stage from a single-cell zygote to adult. The embryo as a whole must be a fully functioning system in its specific environment during every second of its entire development. For this reason, adult anatomy can be understood only in the light of development. An analogy Blechschmidt uses to help elucidate this fact is the course of a river, which “cannot be explained on the basis of a knowledge of its sources, its tributaries, or the specific locations of the harbors at its mouth. It is only the total topographical circumstances that determine the river’s course.”4

        Due to variations in the topographical landscape of the mammalian body, the “course of the inferior [meaning lower] laryngeal nerve is highly variant” and minor anatomic differences are common.5 Dissections of human cadavers found that the paths of the right and left recurrent laryngeal nerves were often somewhat different from that shown in the standard literature, illustrating Blechschmidt’s analogy.6

        Developmental Variations

        The human body begins as a sphere called a blastocyst and gradually becomes more elongated as it develops. Some structures, such as the carotid duct, are simply obliterated during development, and some are eliminated and replaced. Other structures, including the recurrent laryngeal nerve, move downward as development proceeds. The movement occurs because the neck’s formation and the body’s elongation during fetal development force the heart to descend from the cervical (neck) location down into the thoracic (chest) cavity.7

        As a result, various arteries and other structures must be elongated as organs are moved in a way that allows them to remain functional throughout this entire developmental phase. The right RLN is carried downward because it is looped under the arch that develops into the right subclavian artery, and thus moves down with it as development proceeds.8

        The left laryngeal nerve recurs around the ligamentum arteriosum (a small ligament attached to the top surface of the pulmonary trunk and the bottom surface of the aortic arch) on the left side of the aortic arch. It likewise moves down as the thoracic cavity lengthens. The body must operate as a living, functional unit during this time, requiring ligaments and internal connections to secure various related structures together while also allowing for body and organ movement. For the laryngeal nerve, the ligamentum arteriosum functions like a pulley that lifts a heavy load to allow movement.

        As a result of the downward movement of the heart, “the course of the recurrent laryngeal nerves becomes different on the right and left sides.”9 These nerves cannot either be obliterated or replaced because many of them must function during every fetal development stage. Blechschmidt notes that “no organ could exist that is functionless during its development,” an axiom that also applies to the nervous system.10 This movement appears designed to position the left RLN downward as the body elongates.

        In addition, “the laryngeal branch splits up into other branches before entering the larynx at different levels.”11 These many RLN branches serve several other organs with both motor and sensory branches, including the upper esophagus, the trachea, the inferior pharynx, and the cricopharyngeus muscle, the lowest horizontal bandlike muscle of the throat just above the esophagus.12 Neuroanatomists describe larynx innervation as “complicated” and they are still trying to work out the specific targets of its nerve branches. The fact that the left RLN also gives off some fibers to the cardiac plexus is highly indicative of developmental constraints because the nerve must serve both the larynx (in the neck) and the heart (in the chest).

        As noted, after looping around the aorta, the RLN travels back up to innervate the larynx. The superior (meaning upper) and recurrent laryngeal nerves then innervate an area known as Galen’s anastamosis. Other cases exist of one nerve splitting off early and providing direct innervations, and another taking what seems like a circuitous route. One example is the phrenic nerve that arises in the neck and descends to connect to the diaphragm. This is a necessary path, since the pericardium and diaphragm arise in the septum transversum (a thick mass of tissue that gives rise to parts of the thoracic diaphragm and the ventral mesentery of the foregut) in the neck area of the early embryo.

        It then migrates caudally (toward the tailbone) as the embryo enlarges by differential growth of the head and thorax areas, taking the nerve with it. The diaphragm cannot have evolved step-wise, since a partial diaphragm results in an imperfect chest-abdomen separation. Even a small defect results in herniation of the gut contents into the chest–which either compresses the lungs or results in strangulation of the gut.

        A complicated issue still being researched is how the incredibly complex nerve-muscle system, the component nerve fibers, and the laryngeal muscles arise from the neural crest (cells between the epidermis and the neural tube that develop into the brain and spinal cord) and dorsal somites (cells that develop into muscles and vertebrae) respectively in the early embryo, and then migrate anteriorly (towards the front of the body) into their final positions. Without explaining the nerve structure’s design system, function, and ultimate connections, alleging that the RLN is a poor design is a meaningless assertion.

        Thus, the claim that it has to loop up the distance from the ligamentum arteriosum for no reason is invalid. For all these reasons, Prothero’s conclusions are incorrect and poorly considered…

        • Bill says:

          P.S. Please forgive typos, it’s late. In the first sentence above, I meant, “I THINK…” , and not, “I thing…”

          Also, the post did not indicate that this is a response to “Steve”

  3. Tim says:

    How does the juxtaposition of the Vagina prove God is Irish?
    Who else would put a recreational facility next to a sewer!

    Come on Richard! “proof for evolution” Sad man.
    ‘Fish ancestor’… Frigging ridiculous!

    Tell me exactly how the nerve ‘got caught’??? Ie it is not ‘stuck’ there… in the Ovum.
    ‘If ‘evolution’ could rewrite us to have skin instead of scales, lungs instead of gills surely The deity ‘evolution’ could have rerouted the nerve via one of the necessary millions of ‘fortunate mutations’ required to transmutation a fish into a human!

  4. BTW: check out the new layout! 🙂

  5. Tim says:

    I saw the new lay out yesterday Mark… Snazzy!

  6. Rosie says:

    Richard

    Interesting idea but isn’t this an attempt to modernise Christianity by trying to somehow “meld” the atheist false theory of evolution with Creation? Why? The Bible tells us that God is the Creator.

    matter + energy does not equal life (as the Darwinists claim)
    matter + energy + concept (thought/logos) = life (as science knows is the truth and which is also the argument for Creation)

    Deuteronomy 12:29-31 (NIV)

    29 The Lord your God will cut off before you the nations you are about to invade and dispossess. But when you have driven them out and settled in their land, 30 and after they have been destroyed before you, be careful not to be ensnared by inquiring about their gods, saying, “How do these nations serve their gods? We will do the same.” 31 You must not worship the Lord your God in their way, because in worshiping their gods, they do all kinds of detestable things the Lord hates. They even burn their sons and daughters in the fire as sacrifices to their gods.

    Rather than careless drifting there is strong evidence to show that a lot of modern liberalism in religion was deliberately planned and executed.

    A Layman’s Guide to Protestant Theology by William Hordern, p. 74, refers to this:

    The method of liberalism includes the attempt to modernize Christianity. The world, liberals argue, has changed radically since the early creeds of Christendom were formulated; this makes the creeds sound archaic and unreal to modern man. We have to rethink Christianity in thought forms which the modern world can comprehend. Fosdick argued that we must express the essence of Christianity, its “abiding experiences,” but that we must not identify these with the “changing categories” in which they have been expressed in the past. For example, says Fosdick, an abiding experience of Christianity has been its conviction that God will triumph over evil. This has been traditionally pictured in the category of Christ’s second coming on the clouds to destroy evil and set up good. We can no longer retain the outworn category, but we can still believe the truth which this ancient thought form was trying to express. We can continue to work in the faith that, through His devoted followers, God is now building His Kingdom and that there will be a renewing of life, individual and social, to bring it into conformity with the will of God. The essence of the faith is thus retained, argues Fosdick, which the thought form in which it was once clothed has been abandoned.

    A second aspect of the method of liberalism is its refusal to accept religious belief on authority alone. Instead, it insists that all beliefs must pass the bar of reason and experience. Man’s mind is capable of thinking God’s thoughts after Him. Man’s intuitions and reason are the best clues that we have to the nature of God. The mind must be kept open to all truth regardless of from whence it comes. This means that the liberal must have an open mind; no questions are closed. New facts may change the convictions that have become hallowed by custom and time. The liberal will venture forth into the unknown, firmly believing that all truth must be God’s truth. In this spirit, the liberal accepts the higher criticism of the Bible and the theory of evolution. He refuses to have a religion that is afraid of truth or that tries to protect itself from critical examination. (my emphasis)

    Compelling audio lectures

    One of my heroes is Dr A E Wilder-Smith – a world renown chemistry professor and Christian lecturer.

    The combination of these two excellent audio lectures by him argue from a chemical/scientific viewpoint why evolution has to be false and provides instead the compelling argument from induction for Creation.

    “The Five Senses” and
    Creation and Evolution

    They are a bit long and chatty because Wilder-Smith, like Bertrand Russell, is a charming old English academic who reduces the complex to speak simply to an audience of ordinary people, so worth lying down on your bed to listen to them both. The second half of Creation and Evolution is much better than the first half and he does say that the first forty minutes is really preliminary banter so don’t give up – tidy up or cut your toenails while you listen to the first bit!

    The Five Senses looks at the incredible and awe-inspiring complex thought put in to the creation of our five senses (and other animals too – but not the larynx of the giraffe I’m afraid!). It has a bit about ESP at the end too!

  7. Rosie says:

    Chance, Variation and the theory of evolution

    PS In the debate between creation vs. evolution, the fundamental nail in evolution theory’s coffin is the field of study known as information science. All existing life exists as a result of information, organized information.

    Statistical analysts understand that information does not arise by chance.

    AE Wilder-Smith shows in the Creation and Evolution audio clip how to understand information theory and how it proves creationism to be the only logical viewpoint. Matter is not self-organizing; it is merely a medium for information.

    He discusses the classic debate between Bishop Wilberforce and Aldous Huxley concerning the watch-maker. He shows the fallacy of Huxley’s argument. (This fallacy thought up by Wilder-Smith was picked up on by a scientist who developed the idea and provided experiments etc which then won the Nobel Prize for Chemistry.) If you are not familiar with this debate it is a rather essential understanding in order to unravel the Gordian-Knot of evolution theory.

    Creationism understandings are important, he says, because man is accountable to God upon the basis of God being revealed through nature. (Romans 1:18-20)

  8. Richard says:

    Come on Richard! “proof for evolution” Sad man.
    ‘Fish ancestor’… Frigging ridiculous!

    C’mon, Tim! This is target practice! Be happy. 🙂

    That article by Jerry Bergman is excellent. (Thanks for the link.) So it seems that the RLN is not, after all, evidence for evolution. Well, who’d have thunk it?!

    The most logical reason is that the RLN design is due to developmental constraints. Eminent embryologist Professor Erich Blechschmidt wrote that the recurrent laryngeal nerve’s seemingly poor design in adults is due to the “necessary consequences of developmental dynamics,” not historical carryovers from evolution.

  9. Richard says:

    Interesting idea but isn’t this an attempt to modernise Christianity by trying to somehow “meld” the atheist false theory of evolution with Creation? Why? The Bible tells us that God is the Creator.

    No, my post is not an attempt to modernise Christianity. It’s just one in an ongoing series in which my stated objective is simply to review the evidence for evolutionism to see how good it is.

    I’m gradually reading The Greatest Show on Earth: the Evidence for Evolution by Richard Dawkins. My review of Chapter One is here.

    Rather than careless drifting there is strong evidence to show that a lot of modern liberalism in religion was deliberately planned and executed.

    Conspiracy theory or conspiracy fact?!

    Compelling audio lectures

    I look forward to listening to them. (But I have to grow my toenails first.)

  10. Jesus Olivier. The son of Yahweh says:

    Hello.There is no evidence of a mutation causing a positive hereditary change in genetic function, evolution is a theory or a myth just like the immaterial God. I have always wondered how female and male came about and how was it that a species evolved at the exact same time with compatible DNA for conception… when one really thinks about it we should laugh at evolutionists even more than the christian’s, at least the bible is a poor representation of the truth and not just a complete mythical theory of non sense like evolution.
    natural selection is a genetic function, a variation of diversity, it is part of the design of the species it is nothing related to an evolutionary change. The weather changes the animals have been designed to allow for this.

    All life on earth has been created by people from another planet.

    I am the son of one of these men

    infinite love,

  11. Rosie says:

    No, my post is not an attempt to modernise Christianity. It’s just one in an ongoing series in which my stated objective is simply to review the evidence for evolutionism to see how good it is.

    I see. I don’t think Darwin thought the fossil evidence 165 years ago supported it. And I don’t think a single intermediary fossil has ever been discovered, has it?
    Nor is there a mathematical formula.
    There is a mathematical formula to work out the probability that a universe like ours have come into existence as the result of atoms falling together by chance after an explosion though. This is the probability!
    Makes you wonder why evolution theory is taught as though it is fact.

    I’m gradually reading The Greatest Show on Earth: the Evidence for Evolution by Richard Dawkins. My review of Chapter One is here.

    Yes, I well recall your momentous excitement in November 2012 following the completion of Chapter One and the horror of Dawkins’ use of the Argument from Intimidation. That particular form of argument is not one I like to think about.

    I shall look forward to reading your reviews of Chapters Two and Three – whilst your toenails are growing maybe.

  12. Tim Wikiriwhi says:

    Rosie said… matter + energy + concept (thought/logos) = life (as science knows is the truth and which is also the argument for Creation)

    Umm. That is still a materialist/ ‘liberal’ assumption.
    It is not what Historical Christianity believed.
    Matter + energy + thought+ Pneuma (Spirit) = life.

    Anyone with a modicum of understanding of the historic flow of ideas will know that Christianity…esp after the Protestant reformation… has been exposed to ‘trends’… on own hand refining, reforming, purifying and on the other corroding, apostate, and subversive. The desire to force the Divine revelation to accommodate the latest rationalisations is a ongoing onslaught. 3 examples: Communist infiltration post 1917, the modernist belief in evolution (the delusional assumption that the theory of evolution is now an established fact rendering the traditional faith in the literal interpretation of Genesis untenable), and thirdly that the Bible has been overthrown by rationalism.
    Those of us Christians who reject these modern deviations are in the minority.
    Most of the ‘Higher Educated’ Christians are closer to Deists and atheists in their treatment of the scriptures than to Christ and St Paul.

    I agree with Rosie that ‘Information’ is a death nell to the theory of Evolution.
    I mention that issue in my blog post on Bio mimicry Here :
    http://blog.eternalvigilance.me/2012/06/biomimicry-plagiarizing-gods-designs/

    It is particularly important when we consider what DNA is.

    What is also very interesting to note about this particular kind of argument that evolutionist use to discredit the idea of design (Richard) is that at least it focuses on the utterly *Atheistic* nature of the *Real theory* of Evolution as a completely *unguided natural process*.
    It is this point which makes a laughingstock of the so called Christians whom claim that belief in evolution is not in conflict with belief in the bible.
    The reality is they are *polar opposites*.
    Evolution is an *alternative* to Creationism and design.
    It is completely Godless, completely ‘hit and miss’, completely devoid of morality, a cold and brutal denial of a caring moral God.

    I do look forward to more ‘Gems’ from Dawkins.
    It makes for interesting discussion.

  13. Bill says:

    Creationists are so good at solving a problem with another of the same type…..

    Nothing can happen without a cause. God is the cause and he happened with no cause.

    Laryngeal nerve is not poor design. It’s a consequence of “poorly designed” developmental dynamics. I want to know how they think. Seriously…..

  14. marcus says:

    To the vas deferens post. I think the vas deferens is longer, so well, you can store up more ejaculate before orgasm. The proposed shorter vas deferens, you wouldn’t have much sperm in the ejaculate, only what was made and stored in the testicles on demand.

    I don’t know much of the in depth physiological science so enlighten me, I need to learn this stuff anyway.

  15. Pingback: Evidence for Evolutionism #2. The male libido. | Eternal Vigilance

  16. karen says:

    The argument here is really odd. Embryological development has, of course, evolved. Therefore, you can’t invoke it as an alternative “explanation” that somehow falsifies the argument that the placement of the left laryngeal recurrent nerve is evidence for evolution.
    The argument presented here simply takes the explanation that combines embryology and evolution and turns it on its head, declaring, “voila! this is actually evidence against evolution.” But there is no logical basis for that assertion. It’s the intellectual equivalent of the playground come-back, “I know what you are, but what am I?” (If you’re having trouble making sense of that, it’s because it doesn’t make sense.)
    Darwin himself, in The Origin, noted that there was much to be learned about embryology, and that he expected it would be fertile ground for developing a better understanding of the evolutionary process. Simply declaring the contrary is neither evidence nor rational argument.

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