What do they prove?
Vestigial organs are structures for which no use has been found. A list of close to one hundred such organs could be found in textbooks when the idea was first proposed. Now, very few organs are called vestigial organs. This is because man has discovered the functions for many of these structures. Possibly the term "vestigial" is really a word biologists use in place of admitting their ignorance of the function of some organ.
The appendix, the ear muscles, and the third eyelid, or nictitating membrane, are supposed to be organs once used by man at an earlier evolutionary stage. In some animals, such as the rat and the rabbit, the appendix is quite large and functions as a digestive organ. Some evolutionists believe man once had such an appendix, but when his food habits changed he no longer used it. According to the theory the appendix became just a small vestige of the large useful organ. There is evidence now that man's appendix serves as an aid in the body's defence against disease. Since fossils of ancient man consist only of bones, there is no way to determine what the appendix of such early men was like.
The nictitating membrane is used as a third eyelid by some animals, such as frogs and birds. In man, its main use is to collect foreign material that gets in the eye where it can do no damage. Since it has a function, this membrane should not be considered vestigial.
The coccyx is claimed to be a vestigial tool by some evolutionists. During embryonic development the coccyx does temporarily protrude. Normally, when the child is born the "tail" has long since been enclosed in the tissues. It does not shrink, but becomes surrounded by the developing hips and serves as a place of attachment for certain muscles - a very important function. Without this bone we would be unable to sit down with comfort since parts of the muscular system are attached to it. Some forms of backache are due to defects in the coccyx. No fossil evidence has been found to support the idea that the coccyx is a vestigial tail.
Animals also possess structures that are presumed vestiges of useful organs. Some birds such as the kiwi have small wings that they do not use for flying. The python has small bones resembling hip bones, but it has been reported that these small bones assist in the movement of these snakes.
Explaining all apparently "useless organs" as vestiges can lead to some difficult problems. Male mammals have non-functioning mammary glands. If they are vestigial then the males once suckled the young. In some species of frogs, the male has two tiny tube-like structures in the abdomen that resemble the oviducts in the female. They are called vestigial oviducts. If they are vestigial, then did the males produce eggs? If they produced eggs, were they not then females? If females evolved into males, what was the origin of the females? What kind of selective pressure caused the frogs to exchange sex? What selective advantage would there be to exchanging sex?
As mentioned before, many organs once considered vestiges are now known to be useful structures. At one time the endocrine glands were thought to be vestigial organs.
Their great importance as producers of hormones is now understood. The thymus has recently been found to be involved in protecting the body from disease. Perhaps uses will be discovered for the remaining vestigial organs as knowledge progresses.
There are major weaknesses in the vestigial organ argument. First, as has been pointed out, just because no function is known for an organ does not necessarily mean that it is useless. That its removal causes no apparent damage may be because its function is taken over by other organs. This is known to occur in some cases.
Second, why would disuse cause deterioration of an organ? This is Lamarkian reasoning and has certainly not been demonstrated. Even if an organ was never used, this would not change the formation of an organ by the genes. Supposed deteriorations occur because of "loss mutations", but why would these individuals be selected when they were losing the use of an organ that, if not beneficial, was certainly not harmful? Would any of the "vestigial organs" mentioned above have a harmful effect on their possessor? It should be remembered that mutants tend to have less vigour than normal individuals. All things considered then, the mutant would have less chance of survival, not more. If vestigial organs do exist, they cannot be used to support evolution toward increasing complexity because the individual is thereby simplified by having fewer functional organs. Rather, existence of vestigial organs would seem to support application of the second law of thermodynamics rather than evolution. The second law of thermodynamics relates to the idea that all natural systems degenerate. Are not all vestigial organs evidence of degeneration rather than progress or evolution towards complexity?
by Dr. A. J. Monty White
Source: 'Creation News', Spring 1979