The Recurrent Laryngeal Nerve

Summary

The recurrent laryngeal nerve performs essential work along an unusually indirect route.  Its useful branches correct the claim that it does nothing until it reaches the voice box.  They do not establish that every laryngeal signal must travel down toward the chest and back.  The strongest evolutionary argument concerns a shared anatomical arrangement and how it develops, rather than the mere appearance of bad engineering.

Five findings matter:

• The nerve is part of a working network. It supplies most of the voice box's internal muscles, carries sensation, and gives branches to nearby structures. It is a branch of the vagus nerve, not a separate cable running all the way from the brain. Dissections count 8 to 14 branches from each recurrent nerve to the gullet and windpipe.
• The loop follows developing arteries. Right and left nerves turn around different vessels. Unusual arteries are strongly associated with unusual, nonrecurrent nerve routes. That is direct evidence of a developmental constraint.
• The proposed benefits need separate tests. Shared routing and developmental support are serious possibilities. Neither useful branches nor partial overlap with another nerve proves that the full detour is necessary or optimal.
• The extra length has a measured cost. In humans the loop delays signals to the voice box by about 2 thousandths of a second. In a giraffe the delay is estimated at 50 to 90 thousandths, though no one has measured its effect. In tall horses the long left nerve often degenerates. Each side misstates it: Coyne puts the human nerve at three feet, more than twice its measured length, and Bergman says the route has no disadvantage.
• Several familiar replies overstate the anatomy. A nonrecurrent nerve does not itself establish a cause of swallowing trouble. Camelids cannot be dismissed as either having ordinary giraffe-like routing or having no relevant nerves. Their different arrangement makes the comparison more informative.

The nerve therefore supports a historical interpretation of vertebrate anatomy without demonstrating that intelligence played no part in life's origin.  A defensible creationist response accepts the anatomical evidence, investigates specific benefits, and avoids presenting untested advantages as established explanations.  The broader standards for judging such arguments are discussed in Arguments from Bad Design.

Part 1: What takes the detour?

A branch of the vagus

The larynx, or voice box, sits near the top of the windpipe.  Its muscles adjust the vocal folds for sound, breathing and airway protection.  The vagus nerves descend from the head into the neck and chest, carrying many different kinds of signals.  On each side, some fibres leave the vagus as a recurrent laryngeal nerve.  Recurrent means that its course turns back toward the head.¹

The two sides are different:

The aortic arch is the major arterial bend leaving the heart.  The subclavian artery supplies the arm.  The ligamentum arteriosum is the remnant of a fetal blood vessel discussed below.  Both nerves approach the larynx from below, commonly following the groove between the windpipe and esophagus.  Exact relations and branching vary.²

A motor signal bound for the larynx travels downward within the vagus and then upward within its recurrent branch.  These are different named bundles along a continuous nerve-fibre route.  Correcting their names does not eliminate the detour.  Conversely, the vagus would still need to reach the chest and abdomen if the laryngeal fibres left it higher in the neck.  The entire descending vagus cannot fairly be counted as wiring used only for the larynx.

The nerve does more than operate the voice box

The recurrent nerve supplies most intrinsic laryngeal muscles, including muscles that open and close the vocal folds.  The major textbook exception is the cricothyroid muscle, supplied through the superior laryngeal nerve.  Sensation below the vocal folds also travels through the recurrent nerve.  Along its course there are tracheal, esophageal and pharyngeal branches, with contributions to cardiac nerve networks.  These functions are documented anatomy.²

Dissection studies count the branches.  In 1999, Dorothea Liebermann-Meffert and colleagues dissected 23 human specimens and cut 11 more into serial sections.  They report that "Both RLNs gave off 8 to 14 branches, equally distributed to the esophagus and trachea."³  In 1986, Richard Janes and colleagues traced the heart's nerves in 23 cadavers and found that "Parasympathetic cardiopulmonary nerves were found to arise from the recurrent laryngeal nerves and the thoracic vagi immediately distal to them."⁴  So the recurrent nerve feeds the heart's nerve networks near its turn and the windpipe and gullet on the way back up.

This is a substantial correction to an account that treats the route as a functionless wire passing every organ on its way to one distant endpoint.  It is not a demonstration that the route is the only workable one.  Two questions must remain separate: whether tissue along a route needs a nerve supply, and whether laryngeal motor fibres must take that entire route to provide it.

A map showing a useful branch establishes the first point.  Establishing the second would require comparison with an alternative that preserves those branches or supplies their targets another way.  The alternative would also have to develop reliably.  Neither side settles that comparison by drawing a straight line on an adult animal.

Part 2: Development explains the loop; history explains the comparison

How the arteries and nerves become linked

Early vertebrate embryos form paired pharyngeal arches, each containing developing tissues, vessels and associated nerves.  The future laryngeal nerves initially lie close to their targets and the arch arteries.  Subsequent growth separates the head and larynx from the heart.  Where an artery remains across the nerve's route, the nerve retains its relationship to it and lengthens.  It does not disconnect and automatically reconnect on the other side.⁵⁶

The artery pattern changes asymmetrically.  The distal right sixth arch artery disappears, allowing the right nerve's loop to lie higher, beneath the developing right subclavian artery.  Part of that vessel derives from the fourth arch.  On the left, the distal sixth arch persists during fetal life as the ductus arteriosus.  This vessel connects the pulmonary circulation to the aorta; after birth it normally closes and becomes the ligamentum arteriosum.  The left nerve remains caught below the aortic-ductal region.⁵⁶

The adult loop is therefore a consequence of growth from an earlier arrangement.  This is an explanation of what happens during an individual's development.  It does not yet decide why different species begin with such similar developmental relationships.

Why the giraffe makes the historical question vivid

Richard Dawkins made the giraffe the standard case.  In The Greatest Show on Earth (2009) he wrote:  "If you think of it as the product of design, the recurrent laryngeal nerve is a disgrace."⁷  He had watched anatomists trace the whole nerve in a young giraffe at the Royal Veterinary College in February 2009.⁷  His conclusion:  "Any intelligent designer would have hived off the laryngeal nerve on its way down, replacing a journey of many metres by one of a few centimetres."⁷  He calls the nerve "in any mammal" "good evidence against a designer."⁷  Jerry Coyne's Why Evolution Is True, from the same year, calls it "One of nature's worst designs."  He says the direct route is "a distance of about a foot in humans," while the actual nerve "winds up being three feet long."⁸

Coyne's human numbers are too large.  In 2021, Eva Maranillo and colleagues measured the laryngeal nerves in 111 human necks.  The fibres' whole course outside the skull, down the vagus and back up the recurrent nerve, averaged 32.4 cm on the left and 20.8 cm on the right.⁹  Even with a few centimetres added for the stretch inside the skull, the left path is well under half of three feet.  The giraffe figures hold up better.  Mathew Wedel notes that the tallest giraffes have necks up to 2.4 m long, so the pathway from brainstem to larynx "approaches 5 m in the largest individuals."⁶  That fits Coyne's statement that the giraffe's nerve runs about fifteen feet farther than a direct route.

A giraffe preserves the same broad relationship between the left vagus, recurrent branch and great vessels while extending the distance between chest and larynx.  The laryngeal fibres consequently travel down a long neck before returning up it.  Mathew Wedel's anatomical comparison shows the same relative arrangement in humans and giraffes, and uses the distribution among living vertebrates to infer it in extinct animals.⁶

The ancestry argument is that corresponding structures have retained their relationships while body proportions changed.  It predicts a long route in a long-necked descendant without requiring that natural selection positively favoured every extra segment of that route.  An inherited arrangement can remain workable even when changing it would require coordinated changes elsewhere.

Both authors also say why a shorter route never arose.  Coyne writes that natural selection "couldn't manage that, for severing and rejoining a nerve is a step that reduces fitness."⁸  Dawkins says the needed mutation "would have to have constituted a major change — upheaval even — in embryonic development."⁷  The human variants in Part 4 correct the first claim.  No nerve is ever cut and rejoined:  when the artery that normally holds the right nerve down forms elsewhere, the nerve grows straight to the larynx.  That happens in about 0.7% of right-sided nerves examined.  The left side fits Dawkins better.  Wedel reports that a nonrecurrent left nerve is "extremely rare (0.04%)" and always comes with situs inversus, a mirror-image reversal of the internal organs.⁶  A short left route has been seen only when the great arteries themselves are laid out differently.

This is stronger than asserting that an intelligent creator would prefer straight wires.  It connects comparative anatomy with development.  Useful branches are compatible with that history: descendants still need the functions those branches perform.  Finding those functions does not make the shared arrangement disappear.

The inference also has limits.  A living giraffe's nerve is observable; a proposed sequence in extinct ancestors is reconstructed.  Fossil neck bones do not directly preserve the nerve's course.  Moreover, universal statements about identical routing in every living tetrapod are too strong in light of human variants and the camelid evidence below.  Exceptions require the history to explain change, rather than allowing an absolute claim that change is impossible.

What the extra length costs

Dawkins wondered "whether giraffe vocalizations are subject to a delay, like a foreign correspondent talking over a satellite link."⁷  The delay can be measured in people and estimated for giraffes.

In humans it is about two thousandths of a second.  During thyroid operations, surgeons stimulate the vagus nerve in the neck and time the response of the voice-box muscles.  Michael Brauckhoff's group compared 18 patients whose right nerve takes the short, nonrecurrent course with 36 matched patients whose right nerve loops normally.  The median response times were 2.7 and 4.6 milliseconds.¹⁰  The right loop therefore costs about 2 ms.  Thomas Musholt's group cleaned the monitoring records of 1,935 operations and reported mean times of 6.8 ms after stimulating the left vagus and 4.2 ms after the right.¹¹  In a reflex test on 17 healthy volunteers, Bridget Carey and colleagues found 13.2 ms on the right and 15.2 ms on the left, a difference "consistent with the length discrepancy between right and left recurrent laryngeal nerves."¹²  The longer left nerve is not fully offset by faster fibres, but its lag is about 2 ms.

In the giraffe the cost is much larger.  Heather More and colleagues measured motor conduction in the leg nerves of four giraffes at 50.4 metres per second, and estimated a maximum of about 85 m/s from fibre sizes.¹³  If a 5 m pathway replaces a direct one of about half a metre, the extra one-way travel time is roughly 50 to 90 ms.¹⁴  That is a calculation, not a measurement:  no one has timed a giraffe's laryngeal fibres.  For scale, More's team estimated that a signal from a giraffe's foot already takes about 46 ms to reach the spinal cord.¹³  No study has tested whether the laryngeal delay harms a giraffe's breathing, swallowing or calls.

The clearest measured cost of length comes from horses.  Alexandra Draper and Richard Piercy describe equine recurrent laryngeal neuropathy as "a highly prevalent and predominantly left‐sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses, that causes inspiratory stridor at exercise."¹⁵  These nerves carry "the longest motor axons in the horse, measuring up to 2.5 m in length in Draft and Thoroughbred horses, with the left nerve being ∼30 cm longer than the right in tall breeds."  Taller horses are at greater risk, although "it is unclear whether height itself is the principal risk factor or simply a covariate for nerve length."¹⁵  A 2019 study of 16 horses from the same laboratory calls the disease "a length-dependent distal axonopathy," a dying back of the far ends of the longest fibres.¹⁶

This is real evidence that the long route has a price, and it should not be waved away.  It also has limits.  The cause is unknown:  Draper and Piercy list mechanical stress, ischemia, pressure, infection, vitamin deficiency and toxins among the proposals, and put heritability at "from 8 to 40% depending on the breed affected."¹⁵  The best-studied horses come from breeds selected by people for size and speed;  this review found no comparable data for wild equids.  The disease shows that a long nerve is more vulnerable.  Whether a shorter route was available without other costs is the separate question taken up in Part 3.

Part 3: What the design responses actually establish

Development and shared wiring deserve investigation

Michael Egnor states his position explicitly: “Of course ID advocates have never claimed perfect design.”  In comments published by Casey Luskin, he argues that the nerve's course must be evaluated as part of embryonic development and its wider surroundings.  Luskin also emphasizes intermediate branches and the larynx's supply through both superior and recurrent nerves.¹⁷

That response is legitimate as a warning against simplistic reconstruction.  An animal assembles itself while growing; it is not built by installing adult components one at a time.  A shorter adult route could interfere with earlier development or require other changes.  This consideration makes a developmental benefit worth testing.  It does not establish one merely because development is complicated.

In a 2026 interview, engineer Stuart Burgess offers more concrete analogies: loops can accommodate movement during assembly, smaller cables can share a larger cable's route, and separated pathways can reduce vulnerability to a single injury.  He says, “Engineers often put loops in wiring.”  These are real engineering strategies.  Their application to the recurrent nerve remains a biological hypothesis until the relevant benefit and alternatives are compared.¹⁸

For example, demonstrating that a flexible loop permits growth would require measurements of displacement, available slack and the consequences of a different course.  Demonstrating efficient bundling would require comparing the whole network's length, volume or developmental reliability.  The existence of an engineering analogy identifies a useful question; it does not supply the measurement.

Does the nerve support a developing artery?

The developmental-support proposal has more substance than a wiring analogy.  In 1983, Michael Leonard, Grover Hutchins and G. William Moore examined human embryos and fetuses using sections, reconstructions and dissections.  They found the left vagus and recurrent branch positioned as a sling around the developing ductus arteriosus.  The vessel wall beneath the nerves differed from adjacent arterial walls, being thinner and less rich in elastic fibres.⁵

They proposed that local mechanical support could help the ductus develop as a muscular vessel capable of closing after birth, rather than an elastic vessel like the neighboring large arteries.  Their abstract introduces that causal explanation with “It is suggested”.  This article verified the authors' abstract, not the full paper; the observations should therefore not be embellished into an experiment demonstrating that removal of the nerve necessarily prevents normal closure.⁵

The distinction matters.  A nerve positioned to provide support, together with a difference in vessel-wall structure, supports a testable mechanism.  It does not alone establish that support causes the difference, that another arrangement could not provide it, or that the entire long-necked adult route is required.  The proposal concerns a particular left-sided fetal relationship, so it cannot automatically explain every recurrent route on both sides in every species.

The often-cited Gray's Anatomy discussion should be read at this same level.  Lönnig reproduces it as a suggestion, not as a demonstrated necessity.  The underlying study gives a reason to investigate a developmental role; turning it into an established proof of optimal wiring would overstate the evidence.¹⁹

Are the superior and recurrent nerves backups?

The standard division of labour is complementary.  The superior laryngeal nerve supplies sensation above the vocal folds and, through its external branch, the cricothyroid muscle that adjusts their tension.  The recurrent nerve supplies most other intrinsic laryngeal muscles and sensation below the folds.  Losing one therefore need not produce the same deficit as losing the other.¹

That division is not absolute isolation.  Anatomical connections and additional contributions exist.  In 2016, Sadegh Seifpanahi and colleagues stimulated the region of the internal superior laryngeal nerve in 32 healthy volunteers and measured changes in voice acoustics.  The study supports investigating additional motor effects, but its authors explicitly left application to vocal-fold paralysis for further research.  It did not show that an intact superior nerve can fully replace a damaged recurrent nerve.²⁰

Anatomy shows where some of that overlap comes from.  In 1994, B. L. Wu, Ira Sanders and colleagues stained 27 human half-larynges so that the nerves showed through cleared tissue.  In 12 of them, 44%, a nerve ran from the cricothyroid muscle into the thyroarytenoid, a vocal-fold muscle the recurrent nerve also supplies.  About 31% of its fibres were motor fibres.  The authors conclude that "when the CN is present, it supplies a second source of motor innervation to the TA muscle."²¹  Liebermann-Meffert's team went further:  "As the RLN and superior laryngeal nerves supply the same laryngeal muscles and mucosa, this twofold innervation may compensate for some sequelae of RLN injury."³  Maranillo's group adds that electrical recordings in humans show "laryngeal muscles can receive a double innervation."⁹  This is a real anatomical basis for the design side's point that the larynx is not hung on a single wire.  The overlap is partial:  Wu found the extra nerve in fewer than half of larynges, and in one muscle.

This leaves room for overlap and partial compensation.  It does not support the stronger claim that the larynx already has two equivalent supplies, one direct and one recurrent.  Continued speech after an injury also cannot identify the mechanism by itself: the opposite vocal fold, residual innervation and compensation can matter.  Even demonstrated redundancy would leave another question: how much separation is beneficial, and does obtaining it require a loop below the great vessels?

An early warning can also be an injury

Egnor proposes that a chest lesion affecting the nerve can reveal otherwise hidden disease through a change in the voice.  That diagnostic possibility deserves acknowledgement.  However, the same event damages useful function, and his published comments provide no comparative evidence for the claim that this arrangement saves more lives than it costs.¹⁷

A warning produced by damage can be useful without being the reason the vulnerable structure has that position.  Establishing a net protective advantage would require evidence that earlier detection improves outcomes enough to offset the injury and other costs.  Until then, diagnostic usefulness is an observed possibility, while an overall survival advantage remains unmeasured.

Bergman's timing and ontogeny arguments

Jerry Bergman's 2011 paper in the creationist Journal of Creation is the fullest young-earth reply.  He argues that "the reasons for the longer route include both developmental and design constraints."²²  Three of his claims can be checked against the measurements above.

First, he says the route "allows the structures below the larynx to receive signals slightly sooner than the larynx to prepare them for laryngeal action when such function is imminent."²²  Branches that leave the nerve before it reaches the larynx do get its signals first.  That follows from the geometry.  Bergman cites no measurement showing that the windpipe or gullet needs a head start, so the benefit is a proposal, not a finding.

Second, for the giraffe he writes that the impulses on the longer left nerve "are adjusted for by the brain in order for the right/left larynx muscles to function smoothly."²²  He gives no source.  In the giraffe both nerves turn near the base of the neck;  Wedel notes that apart from the artery it hooks under, the right nerve's course "is identical to that of the left."⁶  So the problem in a giraffe is the total delay on both sides, not a mismatch between them.  In humans the left side still lags by about 2 ms.  A timing correction in the brain is possible, but no one has shown it.

Third, he concludes that "No evidence exists that the design causes any disadvantage."²²  That goes beyond the evidence.  Surgical injury, Egnor's own point that chest disease reaches the voice through this nerve, and the length-dependent nerve disease of tall horses are all evidence of some disadvantage.  He also argues that "The evolutionary ‘proof’ becomes worthless when an equally valid explanation exists based on the individual’s historical development, the ontogeny."²²  That treats answers to two different questions as rivals;  the objection on embryology below takes it up.

Bergman's strongest point is the one he shares with Egnor:  a critic who calls the route bad must say how an embryo would build a better one, since the claim implies "that God should have used different embryo development trajectories for all the structures involved."²²  That point limits how much the anatomy can prove.  It does not show the loop is the best route.

Part 4: Natural variants test the claims

A short nerve does not necessarily cause swallowing trouble

Some people have an inferior laryngeal nerve that leaves the vagus in the neck and approaches the larynx without the usual arterial loop.  Henry and colleagues' 2017 meta-analysis combined 53 studies describing 33,571 right-sided nerves.  The pooled frequency of a right nonrecurrent nerve was 0.7%, with a 95% confidence interval of 0.6–0.9%.  The studies included surgical and cadaver observations; this was not a single random survey of healthy volunteers.²³

The variant is strongly associated with an unusual right subclavian artery.  If the arterial segment that normally holds the nerve down does not develop in its ordinary position, the nerve can take a more direct course.  The association is therefore a natural test of the developmental account, not simply an unexplained exception to it.²³

Swallowing difficulty requires special care here.  An aberrant artery can pass behind and compress the esophagus, producing dysphagia lusoria.  Toniato and colleagues explicitly identify the artery as the relevant cause.  Their report also describes a patient with a nonrecurrent nerve who had no postoperative vocal-cord deficit.  It does not establish that a shortened nerve itself causes difficulty swallowing.²⁴

Nonrecurrent nerves nevertheless carry a clinical disadvantage: an unexpected position makes them easier to injure during surgery.  That is a real risk, but it does not prove that the intact nerve is an inferior signal carrier.  Nor does a functioning variant demonstrate that every linked vascular change is harmless.  The nerve's performance, the accompanying artery and the risk created by an unusual surgical landmark are separate issues.

The result is narrower than either slogan.  A laryngeal supply without the ordinary loop can work.  The documented variants do not establish a universally superior replacement that can be inserted into every embryo while leaving all other anatomy unchanged.

What is different in camelids?

Camelids are especially informative because the issue is ordinary anatomy in another mammalian group, not only rare human variation.  The claim that camels and llamas simply lack recurrent laryngeal nerves hides a distinction between a nerve's name, its course and the destination of its fibres.

Jain and Gupta dissected six adult dromedary camels in their 2008 study.  They describe a common nerve stem high in the neck, from which the cranial laryngeal nerve and another descending trunk arise.  A caudal laryngeal branch supplies the larynx directly from the cervical region.  The descending trunk also supplies other structures and continues toward a thoracic nerve network.²⁵

The authors call that descending trunk the recurrent laryngeal nerve.  Its name does not mean that laryngeal signals first make the ordinary giraffe-like journey around a chest artery.  Their described cervical supply is the important finding.  A name-only rebuttal to the camelid exception would miss it.

Lönnig discusses an older study by Hans Joachim Müller of the Bactrian camel and guanaco.  According to the passages Lönnig reproduces, these animals combine direct laryngeal supply with recurrent thoracic branches joining another nerve network.  Müller's original pages were not obtained for this review, so that detailed description remains explicitly secondary.  It should not be silently generalized to every camelid or treated as fully verified from Lönnig's quotation alone.¹⁹

The directly checked dromedary observations already establish the central point: a different laryngeal route can coexist with nerve supply to other neck and chest structures.  This weakens an argument that intermediate targets logically require the usual full laryngeal detour.  It also requires evolutionary descriptions to allow anatomical change.  It does not erase the corresponding vagal network, prove that every part of the camel arrangement is superior, or establish independent creation.

Objections and responses

Does this nerve disprove an intelligent Creator?

No.  Anatomy can test specific claims about performance, development and historical relationships.  It cannot establish that every conceivable creator would avoid a particular route.  A Christian can accept an imperfect or historically constrained system without a logical contradiction.  The more limited empirical issue remains: which account best explains the observed relationships and their variation?

Rejecting a theological conclusion does not make the anatomical evidence irrelevant.  Corresponding nerve-vessel relationships across species still call for an explanation.  A creationist account gains explanatory force when it identifies independently testable design requirements, rather than merely allowing whatever arrangement is found.

If the nerve serves the heart and esophagus, is the detour necessary after all?

Its branches establish useful distribution.  Necessity is a stronger claim about alternatives.  The descending vagus already supplies the chest, and the camel study shows a different arrangement of laryngeal and other branches.  A claim about indispensable bundling must explain why the laryngeal fibres cannot separate earlier while the other targets retain their supply.  Showing the branch network is the beginning of that comparison, not its conclusion.

Does embryology replace the evolutionary explanation?

It explains a different level of the problem.  Embryology describes how a particular animal develops its nerve route.  Common ancestry proposes why related animals inherit corresponding developmental arrangements.  The two explanations can reinforce each other.  A developmental constraint would displace the historical argument only if it independently explained why the relevant similarities should arise without inheritance, with evidence favouring that alternative.

Could the route be a result of degeneration after creation?

That is a proposal requiring historical evidence.  This review found no demonstrated ancestral direct route that subsequently became the ordinary recurrent route through deterioration.  Normal development already produces the loop through the relationship between nerves and arteries.  Calling that relationship damage does not establish an earlier condition or the change that produced it.

Must a critic build a better animal before identifying a cost?

No.  Nerve injury from its relation to surrounding structures is evidence of a vulnerability.  A critic can identify that vulnerability without constructing an entirely new embryo.  However, an assertion that a replacement would improve the organism overall carries an additional burden: account for development, other targets and tradeoffs.  The same standard applies to a defender who declares the observed route optimal.

Issues and unanswered questions

Three important questions remain open in the material examined.  The ductus-support hypothesis needs stronger causal testing before it becomes a claim of necessity.  Camelid nerves need a careful comparison across species using the original older studies and modern tracing methods.  The overall balance of routing length, developmental reliability, injury exposure and possible compensation has not been measured by the design arguments cited here.  Two narrower questions are also open:  whether a giraffe's estimated laryngeal delay of 50 to 90 ms affects breathing, swallowing or calls, and whether the length-dependent nerve disease of tall domestic horses also occurs in wild equids.

These limits should not obscure what is established.  The nerve has essential functions.  Its arterial relationships shape its course.  Direct variants exist.  Useful branches do not by themselves require the full loop, and partial overlap is not full redundancy.

Verdict

The recurrent laryngeal nerve is a working structure with a developmentally constrained route.  Its functions rebut a claim of uselessness; they do not refute common ancestry.  Its shared relationships across species support a historical explanation, while variations show that the arrangement is not absolutely unchangeable.

The strongest creationist response is to accept those distinctions and test proposed benefits.  Mechanical support during development is a specific hypothesis worth investigating.  Claims of complete backup innervation, inevitable swallowing difficulty without the loop, a route with no disadvantage, or demonstrated overall optimality go beyond the checked evidence.  So do claims that the human nerve is three feet long.  Neither declaring the anatomy absurd nor declaring it perfect substitutes for comparison and measurement.

Sources