Ear Muscles

Darwin, Charles.  The Descent of Man, and Selection in Relation to Sex.  Volume 1.  John Murray.  1st edition.  1871.  A book by Charles Darwin, the first of its two volumes, arguing that man descended from a lower form of animal.  Its first chapter gathers that evidence, including rudimentary structures and muscles.  The article uses it for the first list of human rudiments to begin with the ear muscles, and for Darwin's report that he had never heard of a man who could erect his ears.

1. 1a.

   Page 20:  “The extrinsic muscles which serve to move the whole external ear, and the intrinsic muscles which move the different parts, all of which belong to the system of the panniculus, are in a rudimentary condition in man; they are also variable in development, or at least in function.  I have seen one man who could draw his ears forwards, and another who could draw them backwards;”. ↩ ↩ ↩

2. 1b.

   Page 21:  “and from what one of these persons told me, it is probable that most of us by often touching our ears and thus directing our attention towards them, could by repeated trials recover some power of movement.” ↩

3. 1c.

   Page 21:  “The faculty of erecting the ears and of directing them to different points of the compass, is no doubt of the highest service to many animals, as they thus perceive the point of danger; but I have never heard of a man who possessed the least power of erecting his ears”. ↩ ↩ ↩

4. 1d.

   Page 21:  “I am assured by the keepers in the Zoological Gardens that these animals never move or erect them; so that they are in an equally rudimentary condition, as far as function is concerned, as in man.  Why these animals, as well as the progenitors of man, should have lost the power of erecting their ears we cannot say.  It may be, though I am not quite satisfied with this view, that owing to their arboreal habits and great strength they were but little exposed to danger, and so during a lengthened period moved their ears but little, and thus gradually lost the power of moving them.” ↩ ↩ ↩

Strauss, Daniel J. et al.  “Vestigial auriculomotor activity indicates the direction of auditory attention in humans.”  eLife 9:e54536.  Jul 3, 2020.  A laboratory study that used surface electrodes on the skin to record electromyography, the electrical signal of a muscle, from the muscles around each ear while adults read or followed a story.  The ear muscles were more active on the side of the sound or story the listener attended, and the authors call the system a 'neural fossil'.  The article relies on it for the claim that the human brain still drives the ear muscles toward attended sounds. ↩

1. 2a.

   Section Abstract:  “Unlike dogs and cats, people do not point their ears as they focus attention on novel, salient, or task-relevant stimuli.  Our species may nevertheless have retained a vestigial pinna-orienting system that has persisted as a 'neural fossil' within in the brain for about 25 million years.”  “In both experiments, EMG recordings showed larger activity at the ear on the side of the attended stimulus, but with slightly different patterns.”  The printed abstract reads 'within in the brain'. ↩ ↩ ↩

2. 2b.

   Section Introduction:  “The first was Wilson's oculo-auricular phenomenon (Wilson, 1908), in which shifting the gaze hard to one side elicits a 1 to 4 mm deflection of the lateral rim of both ears.”  “Additional evidence comes from a 1987 study (Hackley et al., 1987) of the bilateral postauricular muscle (PAM) reflex (onset latency = 10 ms) to acoustic onset transients.  Increased amplitudes were observed when subjects directed their attention to a stream of tones on the same side as the recorded muscle while ignoring a competing, contralateral stream.” ↩

3. 2c.

   Section Discussion:  “These data provide compelling evidence that our brains retain, in vestigial form, circuitry for orienting the pinnae during both exogenous and endogenous modes of attention.” ↩

4. 2d.

   Section Discussion:  “The neural drive to our ear muscles is so weak that the actual movements (see co-registered video data in the Supplementary Information) are at least one to two orders of magnitude smaller compared to those generated during biting, smiling, grimacing, or voluntary ear-wiggling.” ↩ ↩ ↩

5. 2e.

   Section Discussion, Vestigial Pinna-Orienting:  “The ability to swivel and point the pinnae seems to have been lost during the transition from the primarily nocturnal lifestyles of prosimians to the diurnal ones of New World monkeys, and then, Old World monkeys (Coleman and Ross, 2004).  Mobility continued to decline as the ears became shorter and more rigid, see Waller et al., 2008; Coleman and Ross, 2004.  The musculature degenerated.  For example, an inferior auricular muscle to oppose SAM still exists in lesser apes such as gibbons and siamangs (Burrows et al., 2011), but not in chimpanzees (Burrows et al., 2011) or humans (Cattaneo and Pavesi, 2014).” ↩

6. 2f.

   Section Discussion, Vestigial Pinna-Orienting:  “Although the ear muscles of Old World monkeys have spindles (Lovell et al., 1977), those of humans do not (Cattaneo and Pavesi, 2014).” ↩

7. 2g.

   Section Discussion, Vestigial Pinna-Orienting:  “When pinna-orienting movements became too small to modify acoustic input substantially, possibly 25 million years ago when lesser apes branched off from Old World monkeys, see Gibbs et al., 2007 as discussed in Hackley, 2015, selective environmental pressure ceased.  The neural system became more-or-less 'frozen' in a form optimized for controlling taller, more flexible ears, mounted on a smaller, more spherical head.” ↩

8. 2h.

   Section Discussion, Potential neural mechanisms:  “Using a 4-speaker set-up similar to that of the present Experiment 1, Siegmund and Santibáñez, 1982 found cats’ unconditioned pinna responses to have an EMG onset latency that averaged 78 ms, similar to our value of about 70 ms.” ↩

9. 2i.

   Section Materials and methods, Participants:  “Both older (N = 12, mean age = 62.7 ± 5.9 y, 8 F, all right-handed) and younger adult (N = 16, mean age = 24.1 ± 3.1 y, 8 F, 15 right-handed, one left-handed) volunteers in Experiment one had age-typical, pure tone audiometric thresholds”.  “Only data from the final 21 subjects were retained for Experiment 2.” ↩

Gray, Henry.  Anatomy of the Human Body.  Lea & Febiger.  20th edition.  Edited by Warren H. Lewis.  1918.  A book on human anatomy.  The article uses it for Gray's list of the nine ear muscles, three that move the whole ear and six inside its cartilage, all supplied by the facial nerve, and for his remark that in man these muscles "possess very little action".

1. 3a.

   Page 1035:  “The muscles of the auricula (Fig. 906) consist of two sets: (1) the extrinsic, which connect it with the skull and scalp and move the auricula as a whole; and (2) the intrinsic, which extend from one part of the auricle to another.  The extrinsic muscles are the Auriculares anterior, superior, and posterior.” ↩ ↩

2. 3b.

   Page 1035:  “In man, these muscles possess very little action: the Auricularis anterior draws the auricula forward and upward; the Auricularis superior slightly raises it; and the Auricularis posterior draws it backward.” ↩ ↩

3. 3c.

   Page 1035:  “The intrinsic muscles are the: Helicis major.  Helicis minor.  Tragicus.  Antitragicus.  Transversus auriculae.  Obliquus auriculae.” ↩ ↩

4. 3d.

   Page 1035:  “The Auriculares anterior and superior and the intrinsic muscles on the lateral surface are supplied by the temporal branch of the facial nerve, the Auricularis posterior and the intrinsic muscles on the cranial surface by the posterior auricular branch of the same nerve.” ↩ ↩

5. 3e.

   Page 372:  “The facial nerve, which early enters the common facial muscle mass of the second branchial or hyoid arch, is dragged about with the muscle as it spreads over the head and face and neck, and as the muscle splits into the various muscles of expression, the nerve is correspondingly split.” ↩

Rüschenschmidt, Hannah et al.  “Electromyography of Extrinsic and Intrinsic Ear Muscles in Healthy Probands and Patients with Unilateral Postparalytic Facial Synkinesis.”  Diagnostics 12(1):121.  2022.  A study that recorded the electrical activity of the ear muscles with electrodes on the skin (surface EMG), in healthy people and in patients with unilateral postparalytic facial synkinesis, a one-sided facial condition.  It covers all of the ear muscles, the extrinsic ones that move the whole ear and the intrinsic ones inside it, and reports which of them are active during smiling, ear wiggling and gaze.  The article uses it to show that the ear muscles are still alive and firing.

1. 4a.

   Section Introduction:  “The human auricle contains three extrinsic and six intrinsic muscles [1].  These muscles have been considered vestigial in humans, and are rarely under voluntary control [2].  Like the mimic muscles, all ear muscles are innervated by the facial nerve [1].” ↩

2. 4b.

   Section Introduction:  “Finally, the ear muscles are beneficial for individuals with quadriplegia because these muscles are usually not affected by high-level spinal lesions [2].  For instance, such patients can learn to steer a wheelchair with ear muscle activation [8].” ↩

3. 4c.

   Section 3.3:  “Surface EMG could be recorded from all ear muscles in all healthy subjects.”  “In general, the ear muscle EMG activity was highest during smiling and ear wiggling.  The lowest activity was seen during ipsilateral or contralateral gaze.  Only the obliquus auriculae and the transversus auriculae muscle showed a robust activity during the isolated lateral gaze.” ↩ ↩

Sisson, Septimus.  The Anatomy of the Domestic Animals.  W. B. Saunders, Philadelphia.  2nd edition.  1914.  A veterinary anatomy book on domestic animals.  The article uses it for the horse, its textbook case, where the extrinsic ear muscles are counted group by group and the movement of the ear is compared with a ball-and-socket joint.

1. 5a.

   Page 872:  “The anterior auricular muscles (Mm. auriculares orales) are four in number”.  “The dorsal auricular muscles (Mm. auriculares dorsales) are two in number.”  Page 873:  “The posterior auricular muscles (Mm. auriculares aborales) are three in number”.  “The deep auricular or rotator muscles (M. auricularis profundi s. rotatores auriculae), two in number, are situated under the scutiform cartilage and the base of the concha and cross each other.”  “The scutulo-auricularis profundus major is the strongest of the auricular muscles.  It is flat and is about an inch wide.” ↩ ↩

2. 5b.

   Page 875:  “The base of the concha is rounded and rests in a pad of fat (Corpus adiposum auriculae), so that the movements of the external ear resemble those of a ball-and-socket joint.”  “When the ear is vertical or drawn forward ("pricked up"), the opening is usually directed forward ; conversely, when the ears are "laid back," the opening faces backward.  These movements evidently result from the coordinated actions of several muscles which are very complex and cannot be discussed in detail here.”  “The anterior auricular muscles in general erect the ear and turn the opening forward.” ↩ ↩

Populin, Luis C., and Tom C. T. Yin.  “Topographical organization of the motoneuron pools that innervate the muscles of the pinna of the cat.”  Journal of Comparative Neurology 363(4):600–614.  1995.  A study in cats that injected a nerve tracer into single pinna muscles and mapped the motor nerve cells that drive each one.  The tracer was the B-subunit of cholera toxin linked to horseradish peroxidase, and the cells were found in the facial nucleus, arranged by what each muscle does.  The article uses it for the count of 22 nerve pools that serve the cat's ear.

1. 6a.

   Section Abstract:  “The topographical organization of the 22 motoneuron pools that innervate the pinna muscles of the cat was examined”.  “All 22 pools are found in the facial nucleus, organized as rostro-caudally oriented columns, and arranged according to the action of the muscles they innervate.” ↩ ↩

Populin, Luis C., and Tom C. T. Yin.  “Pinna movements of the cat during sound localization.”  Journal of Neuroscience 18(11):4233–4243.  1998.  A research paper that reports how the outer ear moves in animals when they turn toward a sound or a light.  It finds that the first, fast part of the movement comes about 25 milliseconds after a sound starts and is largest on the ear on the same side as the sound.  The article uses it for the timing of the ear's first movement toward a sound.

1. 7a.

   Section Abstract:  “Prominent pinna movements accompany eye movements when the animal orients to either auditory or visual stimuli.”  “Whereas the long-latency component seemed to occur with the eye movement to the target, the short-latency component was coupled to the onset of the stimulus.”  “The short-latency component (∼25 msec) was highly asymmetrical, being largest in the pinna ipsilateral to the stimuli.” ↩ ↩

Waller, Bridget M. et al.  “Mapping the contribution of single muscles to facial movements in the rhesus macaque.”  Physiology & Behavior 95(1–2):93–100.  2008.  A study that stimulated single facial muscles one at a time in a rhesus macaque, a monkey, and compared the result with humans and chimpanzees.  It finds that the rhesus macaque has great potential for ear movement, which humans and chimpanzees do not show.  The article uses it for the finding that the human face is little altered from the monkey's, apart from reduced muscles around the outer ear.

1. 8a.

   Section Results and Discussion, ear muscles:  “Stimulation of the superior auricularis caused the ear to elevate superiorly (supplemental material 16), but without the medial contraction seen in orbito-auricularis.  Stimulation of inferior auricularis caused the ear to flatten to the head and slight lateral retraction of the scalp (supplemental material 17).” ↩ ↩

2. 8b.

   Section Conclusions:  “Thus, the facial muscles we see in humans appear to be little altered from the format we see in a monkey species, with the exception of the reduction in musculature around the external ear.”  “The most striking difference between the three species is the great potential for ear movement in the rhesus macaque, which is not seen in humans and chimpanzees.” ↩ ↩

Schroeer, Andreas et al.  “Electromyographic correlates of effortful listening in the vestigial auriculomotor system.”  Frontiers in Neuroscience 18:1462507.  Jan 31, 2025.  A laboratory study of 20 young adults with normal hearing, who followed a target podcast while distracting sound streams played at three levels of difficulty.  The posterior ear muscle was more active when the sounds came from behind, and the superior ear muscle was more active in the hardest condition.  The article uses it to show that the superior muscle works harder as listening gets harder.

1. 9a.

   Section Abstract, page 1:  “Twenty participants were recruited”.  “averaged PAM activity was not affected by different levels of effortful listening, but was significantly larger when stimuli were presented from the back, as opposed to the front.  Averaged SAM activity, however, was significantly larger in the most difficult condition, which required the largest amount of effort”.  “We interpret the increased SAM activity to be the response of the vestigial pinna–orienting system to an effortful stream segregation task.” ↩ ↩

2. 9b.

   Section Discussion, page 11:  “If such a movement is large enough, as in many mammals such as cats and dogs, this would impact the head-related transfer function”.  “If attention-driven auricular movements are purely vestigial in our own species, clues as to their original function might be discerned from other primates.  Directly stimulating the 7th nerve branch to SAM in an anesthetized macaque (see the Supplementary material of Waller et al., 2008) showed that maximum contraction yields an upward, essentially rigid, translation of the pinna relative to the ear canal.” ↩

3. 9c.

   Section Discussion, page 12:  “An interesting intermediate step would be a study which exclusively includes participants who are able to voluntarily move their ears.” ↩

4. 9d.

   Section Conclusion, page 13:  “While increased activity of auricular muscles in response to automatic and intentional attention can lead to visible movements of the pinna (Strauss et al., 2020), it is currently not known if they are strong enough to achieve an actual benefit.” ↩

5. 9e.

   Section Discussion, page 13:  “Participants formed a relatively small and homogeneous group, i.e., young and normal-hearing”. ↩

O'Beirne, Greg A., and Robert B. Patuzzi.  “Basic properties of the sound-evoked post-auricular muscle response (PAMR).”  Hearing Research 138(1–2):115–132.  1999.  A research paper on the electrical response recorded from the muscle behind the ear after a sudden sound.  It sets out how the response is best measured, and says the response has been 'ignored by most clinicians'.  The article cites it for the claim that the reflex is used as an objective hearing test.

1. 10a.

   Section Abstract:  “One objective electrophysiological test for deafness involves presenting a brief acoustic stimulus to a subject and measuring the electrical activity evoked in the muscle located just behind the ear (the post-auricular muscle or PAM).”  “The response consists of a simple bipolar compound action potential with a first peak latency of between 12.5 and 15 ms”.  “The response latency and duration are longer in very young infants, but reach adult values by 12 months of age.” ↩ ↩

Purdy, Suzanne C. et al.  “The post-auricular muscle response: an objective electrophysiological method for evaluating hearing sensitivity.”  International Journal of Audiology 44(11):625–630.  2005.  A research paper that tested the post-auricular muscle response as a hearing test in sixteen adults with normal hearing and twenty adults with hearing loss, using clicks at several loudness levels.  The authors found that the response tracked hearing thresholds in people with hearing loss, and that most normal-hearing adults had it at the level used for infant hearing screening.  The article cites it as support for the reflex as an objective hearing test.

1. 11a.

   Section Abstract:  “In hearing-impaired subjects, PAMR thresholds were correlated with audiometric thresholds for the eyes-turned condition.”  “With eyes turned and monaural clicks at 35 dB nHL, the level widely used for infant hearing screening, most normal-hearing adults had a PAMR.  Thus the PAMR is a robust response that may be a useful adjunct to ABR for objective hearing assessment.” ↩ ↩

Online Mendelian Inheritance in Man.  Entry 129100: Ears, Ability to Move.  Johns Hopkins University.  n.d.  Retrieved Apr 19, 2022.  “The ability to move the ears,”.  A secondary source, a catalogue entry that summarises two older studies: L. Linder's 1949 study in Hereditas 35 (suppl.):620–621, and M. Hernandez's 1980 study.  The article uses its figures for how many people can move their ears and how the ability runs in families.  Mirror:  Archive.org

1. 12a.

   Section Entry text:  “Linder (1949) examined 104 men and 70 women and found the ability to move the ears in 54% and 22%, respectively.  The frequency of the trait among sibs of probands was 47% and among parents was 74%.  However, in 5 of 24 cases both parents lacked the trait, leading Linder (1949) to suggest that the ability is inherited as a somewhat irregular dominant.  In Barcelona, Hernandez (1980) found that 19.9% of men and 9.57% of women could move their ears.” ↩ ↩

Bair, J. H.  “Development of voluntary control.”  Psychological Review 8(5):474–510.  1901.  A 1901 laboratory study from the University of Michigan that set out to develop control over one small ear muscle, the retrahens aurem, which most people cannot contract.  It worked with fourteen subjects, only two of whom could move their ears at the start, and recorded the ear movements on a kymograph, a rotating drum that draws a trace of them.  The article uses it to show that moving the ears can be learned.

1. 13a.

   Page 475:  “Of the fourteen subjects who rendered us their services, only two could move their ears at the beginning of the experiment and these only when vigorously raising their brow.  The remaining twelve had no idea of the movement and could not produce it, however hard they tried.” ↩ ↩

2. 13b.

   Pages 479–480:  “All of our subjects acquired control over this muscle in the same way, and the introspections were also fairly uniform, so that the results, in general, of each subject corroborate those of the others.”  The sentence begins under the running head of page 479 and ends after the head of page 480.  The running heads read:  “DEVELOPMENT OF VOLUNTARY CONTROL. 479”.  “480 J. H. BAIR.” ↩ ↩

3. 13c.

   Page 483:  “In this stage the retrahens is always contracted by biting the jaws together or vigorously raising the brow.  The ear was thus first reached by innervating a group of muscles over which one has already control.” ↩

Chanthaphun, Siwaphorn et al.  “Development of a training paradigm for voluntary control of the peri-auricular muscles: a feasibility study.”  Journal of NeuroEngineering and Rehabilitation 16:75.  2019.  A feasibility study, a small first test of a training method, in which 10 people completed the protocol.  The senior authors disclose that one of them owns the company whose device was tested.  The article uses its finding that most people who finished the training could control these muscles.

1. 14a.

   Section Background:  “The peri-auricular muscles (PAMs) can be found in 95% of the population but do not currently serve any physiologic function [5–8].” ↩

2. 14b.

   Section Abstract:  “The 10 who completed the protocol, finished the facilitation phase in 3 to 9 sessions and achieved some level of voluntary auricle movement that ranged between 1 and 5 mm.”  “Sixty percent of those who completed the facilitation phase were able to learn and demonstrate functional voluntary control of the vestigial PAMs.”  “with 20% deemed Poor/Non-Learners and unable to complete even the most basic game following training.” ↩ ↩

Wiedersheim, Robert.  The Structure of Man: An Index to His Past History.  Macmillan.  2nd German edition.  Translated by H. Bernard and M. Bernard.  1895.  A comparative anatomy textbook for medical students, written by a German professor at Freiburg and translated into English, with notes and a preface by G. B. Howes, professor of zoology at the Royal College of Science, London.  It sets out the parts of the body that link man with lower animals, and its conspectus lists the organs its author calls vestigial.  The article uses it for the 1895 list that puts the ear muscles among the vestigial organs, and for Wiedersheim's remark that in most people the capacity to move them is entirely wanting.

1. 15a.

   Page 107:  “Muscles round the pinna : attrahens, retrahens, and attollens auriculam (cf. Figs. 70 and 71).  The capacity for moving these muscles varies greatly in individuals.  In most people it is entirely wanting ; and the retrogressive character of these muscles is due to the degeneration of the pinna”. ↩

2. 15b.

   Page 109:  “Taking all the facts into consideration, this intrinsic musculature of the pinna, which is no longer under the control of the will, must be considered as the vestige of a primitive apparatus functional either for the opening and closing, or for the widening and narrowing of the auditory funnel and the external auditory passage”. ↩

3. 15c.

   Pages 200–201:  Section B of the conspectus, headed on page 200:  “Retrogressively modified, the Organs having become wholly or in part functionless ... For the greater part Organs which may be rightly termed Vestigial”.  Page 201:  “Muscles of the pinna and the Musculus occipitalis.” ↩ ↩

Coyne, Jerry A.  Why Evolution Is True.  Viking.  2009.  A book by Jerry A. Coyne, published by Viking in 2009.  The article uses it for Coyne's own words on the ear muscles, which he called "silly ear muscles" while arguing that such features make no sense if species were specially created.

1. 16a.

   Page 58:  “Evolutionary theory doesn't say that vestigial characteristics have no function.  A trait can be vestigial and functional at the same time.  It is vestigial not because it's functionless, but because it no longer performs the function for which it evolved.” ↩

2. 16b.

   Page 64:  “Sometimes useful, but often not, they're exactly what we'd expect to find if natural selection gradually eliminated useless features or refashioned them into new, more adaptive ones.  Tiny, nonfunctional wings, a dangerous appendix, eyes that can't see, and silly ear muscles simply don't make sense if you think that species were specially created.” ↩ ↩

Menton, David N.  “The plantaris and the question of vestigial muscles in man.”  CEN Technical Journal 14(2):50–53.  2000.  A short argument paper about the calf muscle called the plantaris, which the author says is neither vestigial nor useless.  It says the plantaris serves a sense of limb position and muscle contraction, that a muscle unused for a lifetime would not stay healthy, and that any muscle still in the body is overwhelmingly likely to serve some function.  The article uses it for those general arguments, that small muscles are not useless and that an unused muscle would waste away.

1. 17a.

   Page 50:  “The muscles most frequently claimed to be vestigial in man are the auricular muscles of the ear, the erector pili muscles of hair follicles, and the plantaris muscle of the calf of the leg.  All of these muscles are relatively small and give the appearance of producing little or no useful work by their weak contractions.” ↩

2. 17b.

   Pages 50–51:  “It is unlikely that any muscle that was virtually unused for the lifetime of an individual (to say nothing of generations of individuals over millions of years) would remain as healthy muscle tissue.” ↩ ↩

3. 17c.

   Page 51:  “It seems overwhelmingly likely that any muscle in the body that actually exists in the present, serves some function.” ↩

Sanders, Lita.  “Badly designed arguments: 'vestigial organs' revisited.”  Creation Ministries International.  Nov 25, 2011.  A reply by Lita Sanders (née Cosner) for Creation Ministries International, a ministry that defends Genesis history, to a reader who asked for a rebuttal of a list of supposedly useless organs.  It goes through the list and finds that not one item fits the definition of a truly vestigial organ, and it suggests that the ear muscles could help remove wax from the ears.  The article uses it for that wax proposal, which it says no primary source supports.

1. 18a.

   Section Extrinsic ear muscles:  “A CMI biologist suggested that one function of ear muscles could be to help remove wax from the ears.  When a person is chewing, or smiling, etc. the ear muscles move the ears.  This gradually moves the wax outwards, cleaning the ears.  But there could be other functions also.” ↩ ↩

Menton, David N.  Ear Muscles.  Creation Ministries International.  Nov 6, 2007.  A reply that David N. Menton wrote in 2003 to an enquirer at CMI-Australia, published as a web page by Creation Ministries International on 6 November 2007.  Its only citation is "'The Ear Muscles', p.58 in "Vestigial Organs" Are Fully Functional, Bergman & Howe, 1990."  The article uses it as one of the creationist replies on the ear muscles: Menton calls the movements "slight" and says no hearing benefit is known.

1. 19a.

   Paragraph 1:  “The auricularis muscles are a favorite example of evolutionists as vestigial muscle presumably left over from when we could move our ears (auricles) about like a rabbit.  Clearly, the ability to orient the ears assists in sensing the stereo imaging of sound (location and distance).” ↩

2. 19b.

   Paragraph 2:  “The ability of humans to move the auricle in a grossly noticeable way varies from individual to individual but generally the movements are slight.  Are any of these movements, when noticeable or measurable, able to improve our hearing or stereo perception?  None that we know of at this time.” ↩ ↩

3. 19c.

   Paragraph 3:  “The external auricular muscles are typically grouped with the muscles of facial expression.”  “All of the facial muscles (including the auricularis muscles) are innervated by the same cranial nerve, the facial nerve.” ↩

Bergman, Jerry.  “Ear Muscle "Wiggle": A Vestigial-Organ Claim That We Should 'Turn a Deaf Ear To'.”  Creation-Evolution Headlines.  Jul 24, 2020.  A young-earth creationist reply by a biologist and frequent writer on vestigial organs, aimed at the 2020 eLife attention study as reported in a university press release.  It argues that the ear muscles stabilise and pad the ear and that their attention-driven activity is a form of body language, and it asks why evolution would lose a useful ability.  It is the only creationist text found that answers the attention studies directly. ↩

1. 20a.

   Section Opening section, before the heading Evolutionary claims:  “In my book Useless Organs, I described how these muscles have several very important functions, including serving as a framework supporting and stabilizing the pinna.”  “Another function is to serve as padding to protect the underlining structures in the temples.” ↩

2. 20b.

   Section A better explanation for the auriculomotor system:  “It is not to move the ears (as the vestigial-organ explanation claims) but rather—as the authors themselves note—to communicate with others.  They are part of the facial response to sounds of interest and as part of the body communication system.” ↩ ↩

3. 20c.

   Section Evolutionary claims:  “The researchers were able to record the signals that control the very small, generally invisible, movements of the pinna by surface electromyogram (EMGs) probes placed in the skin near muscles connected to the pinna.” ↩

4. 20d.

   Section A better explanation for the auriculomotor system:  “Actually, no one has any idea why movement of the auricle to better focus on a certain sound source, as cats and some dogs do, would be lost by evolution.” ↩

Coleman, Mark N., and Callum F. Ross.  “Primate auditory diversity and its influence on hearing performance.”  Anatomical Record Part A 281(1):1123–1137.  2004.  A study that measured the outer ears of cadaver specimens from nearly every primate family and worked out a shape ratio, height against width.  Primates outside the monkey and ape group have ears that are taller and narrower than those of monkeys and apes.  The article uses it for the change in ear shape across the primates, from tall and narrow ears to ears of equal height and width.

1. 21a.

   Section Abstract:  “It was found that nonanthropoids have a significantly higher ratio than anthropoids, although the actual height was not found to differ.  This indicates that most nonanthropoids have ears that are tall and narrow, whereas monkeys and apes are characterized by ears with more equal height and width dimensions.” ↩

Cobo, J. L. et al.  “Searching for proprioceptors in human facial muscles.”  Neuroscience Letters 640:1–5.  2017.  A histology study of two facial muscles, the zygomatic major and the buccinator, taken from Spanish cadavers and stained for nerve fibres and two proteins linked to touch and stretch sensing.  It starts from the accepted finding that facial-nerve muscles lack typical spindles and reports Ruffini-like sensory corpuscles that could stand in for them.  The article uses it to show that a missing spindle is normal for human facial muscles, which are still finely controlled.

1. 22a.

   Section Abstract:  “The human craniofacial muscles innervated by the facial nerve typically lack muscle spindles.  However these muscles have proprioception that participates in the coordination of facial movements.” ↩

Omstead, Kailey M. et al.  “Mammalian facial muscles contain muscle spindles.”  Anatomical Record 306(10):2562–2571.  2023.  A comparative histology survey that counted spindles in the upper lip and cheek muscles of a broad range of mammals.  It found spindles in facial muscles, fewest in humans and other primates and most in carnivores and the horse;  the authors warn that the sample was small and some groups were missing.  The article uses it to show that few or no facial spindles is a primate-wide trait, not a mark of the ear alone.

1. 23a.

   Section Abstract:  “Our results indicate that mammalian facial muscles contain muscle spindles, supporting our hypothesis.  Contrary to our prediction, though, humans (and other primates) had the lowest number of muscle spindles.  We instead found that the carnivoran sample and the horse sample had the greatest number of spindles.” ↩

Hackley, Steven A.  “Evidence for a vestigial pinna-orienting system in humans.”  Psychophysiology 52(10):1263–1270.  2015.  A review that argues the brain's circuits for turning the ears have survived as a vestigial remnant, one that no longer does its original job.  It gives three lines of evidence: a 2–3 mm curl of the ear's edge and electromyography (EMG, the electrical signal of a muscle) when the eyes turn hard aside, a weak EMG response to an unexpected sound from behind, and EMG bursts during an attention task.  The article uses it for the thesis that these neural circuits still survive in humans.

1. 24a.

   Section Abstract:  “Although some people can voluntarily move their ears, overt reflexive control of the pinnae has been lost during the course of primate evolution.  Humans and apes do not move their ears to express emotion, they do not defensively retract them when startled, and they do not point them at novel, salient, or task-relevant stimuli.  Nevertheless, it is the thesis of this review that neural circuits for pinna orienting have survived in a purely vestigial state for over 25 million years.” ↩

2. 24b.

   Section Abstract:  “(1) Shifting the eyes hard to one side is accompanied by electromyographic (EMG) activity in certain ear muscles and by a barely visible (2-3 mm) curling of the dorsal edge of the pinna.  (2) The capture of attention by a novel, unexpected sound emanating from behind and to one side has been found to trigger a weak EMG response in the muscle behind the corresponding ear.  (3) Reflexive EMG bursts recorded during a selective attention task suggested that subjects were unconsciously attempting to orient their ears toward the relevant sounds.” ↩

3. 24c.

   Section Abstract:  “It is suggested that the postauricular reflex to sudden, intense sounds constitutes a vestigial startle response, but that the reflex arc is dominated by a pathway that bypasses the main organizing center for startle.” ↩

Schroeer, Andreas et al.  “The vestigial pinna-orienting system in humans briefly suppresses superior auricular muscle activity during reflexive orienting toward auditory stimuli.”  Journal of Neurophysiology 132(2):514–526.  2024.  A laboratory study of 10 adults with normal hearing, who heard sudden sounds from one side in silence and during a podcast while two ear muscles were recorded by electromyography.  The posterior ear muscle became more active on the side of the sound, but the superior ear muscle went briefly quieter, which the authors say points to a more complicated system than assumed.  The article uses it to show that the two muscles do not simply respond together.

1. 25a.

   Section Abstract:  “Although ipsilateral PAM activity increased in response to transient stimuli, the SAM displayed the opposite behavior, i.e., a brief, ipsilateral suppression of activity.”  “the presence of synchronized excitatory and inhibitory components in different auricular muscles points toward a coordinated attempt at reflexively orienting the pinna toward a sound.” ↩

Bergman, Jerry.  “Do any vestigial structures exist in humans?”  CEN Technical Journal 14(2):95–98.  2000.  A short argument paper, not a study.  It says the list of vestigial organs in humans "has shrunk from 180 in 1890 to 0 in 1999", and it rejects a "revisionistic" definition of a vestigial organ as one that has merely been reduced in size or function.  The article uses it for the author's reply to Asimov's two examples, the coccyx and the ear muscles, and for his claim that Asimov's conclusions rest on evolutionary assumptions rather than evidence.

1. 26a.

   Page 95:  “Asimov provides two examples of a vestigial organ: (1) the tiny bones posterior to the sacrum called the coccyx (which Asimov claims were 'once meant for a tail'); and (2) the small muscles around the ears (which Asimov claims are 'unworkable muscles once meant to move the ears').  As we will see, these conclusions are not based on empirical evidence but instead on evolutionary assumptions.” ↩

Guest, Julian F. et al.  “Impacted cerumen: composition, production, epidemiology and management.”  QJM 97(8):477–488.  2004.  A clinical review of impacted ear wax that covers what wax is made of, how it is produced, how common it is and how it is managed.  It reports that some 2.3 million people in the UK had wax problems serious enough to need management, and that the evidence on treatments is inconsistent.  The article cites it for its statement that the physiology of wax is poorly characterized.

1. 27a.

   Section Abstract:  “Despite this, the physiology, clinical significance and management implications of excessive and impacted cerumen remain poorly characterized.” ↩