Badly designed arguments—‘vestigial organs’ revisited
Published: 17 December 2011(GMT+10)
The argument from ‘vestigial organs’ has been refuted many times by creationists, but some evolutionists still think it is a good argument against creation. Halldór M. from Iceland writes:
Greetings, I was wondering if you could write an article that refuted this article here: [Web link removed as per our feedback rules—Ed.].
Not sure how scientific they are or if their information is accurate but it seemed like a very updated version of the vestigial argument for evolution.
CMI’s Lita Cosner replies:
I’ll take these ‘useless organs’ one at a time. Sometimes the author of the list didn’t use the proper name; when that’s the case, I’ll use the author’s name for it in quotes, with the proper name in parentheses.
Human Vomeronasal Organ: The contention that there is no possible function of the human VNO is unsupported.1
Extrinsic ear muscles: To quote from a Journal of Creation article (read the whole article at The plantaris and the question of vestigial muscles in man):
“While virtually all of the larger muscles of the body have obvious (as well as some not so obvious) mechanical functions, smaller muscles are not necessarily useless. For example, two of the smallest muscles in the body, the stapedius and the tensor tympani, serve to dampen the movements of the auditory ossicles and the tympanic membrane (respectively) preventing loud sounds from overloading these delicate structures of the middle ear. In general, most small, short muscles of the body produce fine adjustments in the movement of larger muscles.
“One of the problems with the whole concept of vestigial or functionless muscles is the well-known fact that unused muscles quickly degenerate. People ranging from astronauts exposed to a prolonged weightless environment, to those confined to long bed rest, lose a significant amount of muscle mass in only a few months. In short, muscle mass is a matter of ‘use it or lose it’. 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. It seems overwhelmingly likely that any muscle in the body that actually exists in the present, serves some function.”
It is in principle not possible to prove that an organ is useless, because there is always the possibility that a use may be discovered in the future.
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.
Wisdom teeth: Wisdom teeth almost exclusively cause problems in countries where the diet consists of soft foods. Through most of human history, the average diet consisted of foods which required more work to chew, resulting in better jaw development with more room for the teeth. See Are wisdom teeth (third molars) vestiges of human evolution?
“Neck” (or cervical) ribs: I would consider something that develops in only 1 of 200 people and causes problems when it does to be pathological and a result of abnormal development. In short, an example of human devolution, rather than evolution.
“Third eyelid” (plica semilunaris): This is one of the places where the author of the list shows his/her ignorance. The plica semilunaris actually has a critical function for the health of the eye. It secretes the sticky substance that hardens into the crust we sometimes find around our eyes when we wake up. This substance surrounds any particles that find their way into the eye, making them less likely to scratch the eye, and making it easier for the tears and eyelids to remove the particles from the eye. If we didn’t have this organ, our eyes would be much more prone to painful injuries that would affect our sight, and also make us more susceptible to related infections.
Darwin’s point: To quote another Journal of Creation article (Vestigial arguments: remnants of evolution):
“‘Darwin’s point’ is a cartilaginous bump on the rim of the outer ear found in about 10% of humans. This is an autosomally dominant trait with incomplete penetration, and is ‘thought to be the vestige of a joint that allowed the top part of the ancestral ear to swivel or flop down over the opening to the ear.’
“Spinney follows plastic surgeon Anthony Sclafani of the New York Eye and Ear Infirmary in New York City, arguing that the genetics of the Darwin’s point condition suggest that it is an evolutionary vestige:“‘The trait is passed on according to an autosomal dominant pattern, meaning that a child need only inherit one copy of the gene responsible to have Darwin’s point. That suggests that at one time it was useful. However, it also has variable penetration, meaning that you won’t necessarily have the trait even if you inherit the gene. “The variable penetration reflects the fact that it is no longer advantageous,” Sclafani says.’
“However, this is merely twisting genetics into an evolutionary tale. Autosomal dominant traits can arise through mutations and either have no functional importance (such as the widow’s peak) or are harmful (such as Huntington’s disease), so it does not have to be functional to have any sort of dominance. Rather, the combination of autosomal dominance and incomplete penetration suggest that it’s a mutation, but it does not affect the survival of the organism. And since it is a dominant trait, it is able to find its way into the population more readily than a mutation that gives rise to a recessive allele. Therefore, Darwin’s point merely provides at best an example of natural variation and at worst an example of genetic degeneration, neither of which is a problem for the biblical worldview.”
Subclavius muscle: The Wikipedia description (at the time of writing) of the muscles function says that it carries the shoulder downward and forward, and draws the clavicle inferiorly as well as anteriorly. In addition, in the event of a fractured clavicle (the clavicle is the most frequently-fractured long bone), the subclavius muscle protects the brachial plexus and the subclavian muscles.
This hardly seems vestigial to me! The comments on the unlikelihood of the survival of vestigial muscles above also apply here.
Palmaris (longus) muscle: While this muscle is highly variable, and its absence (in around 10% of the population—most frequently in Caucasian people but less frequently in other populations) isn’t associated with a measurable loss in grip strength, the fact that it isn’t badly atrophied in the people who possess it indicates that it has some use. (See also Selfish gene theory, the ENCODE project and vestigial muscles)
Male nipples: The existence of male nipples is attributable to design economy—both boy and girl babies develop from a common blueprint, with hormones controlling the development of sex-specific traits. It is unclear whether male nipples are useless, however. They’re full-sized, equipped with blood vessels and nerves—in other words, they have everything a functioning organ has. The most commonly-cited possible purpose for them is sexual stimulation. See Male nipples prove evolution?
Erector pili: These muscles, found in all mammals, are what causes someone’s hair to stand up when cold or frightened. The hair can trap more air when it stands on end, so forms an insulating layer to help to retain heat. Evolutionists say that humans have so little body hair now that the erector pili muscles are useless. But muscle contraction in and of itself helps to retain body heat, and they also have an important role in keeping the skin’s oil glands unblocked. See Blind fish, island immigrants and hairy babies.
Appendix: This old evolutionary stand-by has long been shown to have a vital purpose, especially in early childhood. It’s a storehouse of the ‘good’ bacteria that populate the intestines and which are essential for digestion. See Appendix: a bacterial safe house and More musings on our useless appendix.
Body hair: This person’s list acknowledges the eyebrows’ function in keeping sweat out of the eyes (eyelashes are also useful for keeping debris out of the eyes). In addition, hair on the top of the head is useful for insulation (a great deal of body heat is lost out of the top of the head) and protection from sunburn. On other parts of the body, hair may have a sensory function; hair movement is transferred to sensory nerves within the skin. And as mentioned earlier, hairs keep the pores in the skin open and healthy, allowing movement of oils onto the skin from the glands at the base of the hairs.
Plantaris muscle: The plantaris has an unusual number of proprioceptive receptor end organs, so it probably plays a role in proprioception. And it does weakly aid in plantarflexion of the ankle joint and flexing of the knee joint. (The plantaris and the question of vestigial muscles in man)
Thirteenth rib: It is unclear whether this condition is referred to distinct from the cervical ribs above; apparently this is a different condition as it is said to affect 8% rather than 5% of the population. But again, this could be attributed to a developmental anomaly (when people are born with six fingers, no one claims it is some sort of evolutionary ‘throwback’).
Male uterus/female vas deferens: These, while they make up two entries on this person’s list, only merit one entry, because their cause is the same. In the earliest stages of development, a baby develops the beginnings of both the male and female reproductive systems. Hormones determine which system develops fully. Rarely, hormones can cause the wrong system to develop partially, resulting in some level of gender ambiguity. This is not an example of vestigiality; no evolutionist would argue that humans were at some point androgynous.
Fifth toe: The fifth toe provides width and flexibility to the foot while walking barefoot. Problems with the fifth toe largely arise from wearing shoes that fit improperly.
Pyramidalis muscle: Again, see the comments about the unlikelihood of the survival of truly vestigial muscles. Just because a muscle is minor doesn’t mean it is useless. This muscle helps to strengthen the rectus sheath.
Coccyx: The underappreciated tailbone actually has a couple important functions. It is an anchor point for several muscle groups, and removal of the coccyx can cause difficulty in sitting or standing up, difficulty in giving birth, and incontinence.
Paranasal sinuses: I have never heard anyone argue that our sinuses are useless before! Many roles have been suggested for them, including lightening the weight of the front of the skull, increasing resonance of the human voice, insulating the sensitive dental roots and eyes from the rapid temperature changes in the nasal cavity, and humidifying inhaled air.
The creation model allows for deterioration of a perfect creation.
In short, not one of the items on the list fits the definition for a truly vestigial organ.
However, there are two principles that need to be stated about the very concept of vestigial organs, an idea that has been very destructive of scientific progress (why research something that is deemed useless?):
First, it is in principle not possible to prove that an organ is useless, because there is always the possibility that a use may be discovered in the future. This has happened with over a hundred alleged useless vestigial organs which are now known to be essential.
Second, even if the alleged vestigial organ were no longer needed, it would prove devolution not evolution. The creation model allows for deterioration of a perfect creation. However the particles-to-people evolution model needs to find examples of nascent organs, i.e. those which are increasing in complexity.
- On possible functions of the human VNO, please see this technical article: Meredith, M., Human vomeronasal organ function: a critical review of best and worst cases, Chemical Senses 26(4): 433–445, 2001; chemse.oxfordjournals.org/content/26/4/433.full. Return to text.