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True Vestigial Structures in Whales and Dolphins
What Is a Vestigial Structure?
Webster's Third New International Dictionary defines a vestige as "a small and degenerate or imperfectly developed bodily part or organ that remains from one more fully developed in an earlier stage of the individual, in a past generation, or in closely related forms." It is those vestigial organs that show signs of coming from past generations that support the theory of evolution.
From the beginning, creationists have disputed either the existence or importance of vestigial organs. Robert Kofahl declares in his Handy Dandy Evolution Refuter:
On the other hand, leading scientists, such as the late zoologist and geneticist, Theodosius Dobzhansky, have continued to support vestigial organs as evidence for evolution. In his text, Evolution, Genetics, and Man, Dobzhansky wrote, "There is, indeed, no doubt that vestigial rudimentary organs silently proclaim the fact of evolution."
To speak to the statement by Kofahl, then, seems to be in order. Let us take his statement one sentence at a time.
When Kofahl says that advancing knowledge has discovered uses for most of what were thought to be vestigial organs, he is at least partly correct. Compared to what scientists thought in the last century, scientists today regard fewer organs as truly vestigial. Among the recent scientists who have been noting uses for formerly held vestiges is Russian zoologist Alexy Yablokov. His book, Variability of Mammals, discusses the important functions played by the pelvic bones and whiskers of whales—two features that were formerly regarded as vestiges.
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Does this signify that, given enough time, scientists will soon find uses for all so-called vestigial organs and that we would be well-advised today in giving up the vestigial-organ argument as a case that is doomed? This is what creationists would like us to suppose. But this attitude is based on a misunderstanding of why many structures regarded in the past as vestiges are today regarded as something else.
In a chapter entitled "Variability and the Problem of Vestigial Organs," Yablokov helps us clear up the misunderstanding. He sees much of the problem as having been caused by "vague definitions of the concept of vestigial organs," particularly "the vague or imprecise understanding of the concept of vestigial organ present in the works of Darwin ..." (pp. 232-233). His purpose is to tighten up the definitions in order to provide scientists with a clearer idea of what criteria must be met before a structure can be called vestigial.
But even with tighter definitions, the organs no longer labeled as vestigial do not cease to have value in demonstrating evolution, as creationists might think. For example, when Yablokov denies that pelves and whiskers in whales are truly vestigial, he continues to affirm that they are clear throwbacks to an earlier evolutionary stage. As he states on page 240, "The structure of these organs was modified by a significant change in function at some time in their evolution." Because of his tighter definitions, he prefers to speak in such cases "about the vestigiality of functions rather than the vestigiality of organs" (p. 246). This means that creationists gain very little by the "advancing knowledge" that keeps discovering useful, but altered, functions for organs formerly defined as "vestigial." These organs still demonstrate descent with modification.
In Yablokov's view, the problem with most of the previously held examples of vestigial organs is that they were organs "present in all the individuals of a given species." But, "it is observed in all cases that such organs or structures, inherited by the whole population, have a functional significance and logically cannot be named as vestigial." To Yablokov, an organ should be taken as vestigial only if it is one which develops in some individuals but is not characteristic of the whole population (p. 241). And he adds, "It has been known for a long time that such organs exist in animals."
Armed with this clearer concept of vestigial organs, we can now look at the second sentence in Kofahl's statement. Here he says that any true vestigial organ would show the loss of structure and design instead of the development of something new. If we drop "design," Kofahl is perfectly correct. A true vestigial organ is indeed an organ that has lost its original structure. It has also lost its function. Individuals possessing a vestigial organ don't differ in fitness from those without it. The organ is simply a leftover. Therefore, Kofahl seems to be accepting the concept.
But when he speaks of "design," he implies a designer, a master architect who puts the organs in place; animals were perfectly made by the perfect maker who knew exactly what was to be done.
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Given such a position, it would seem frivolous if this maker put some parts in that were of no use. But "design" is a concept that has no usefulness in science. As Richard Aulie points out:
This brings us to Kofahl's last sentence. There he states that, since vestigial organs show a loss of structure, they don't help evolution, since evolution requires "evidence for the production of new organs...." This sentence shows Kofahl's misunderstanding of why vestigial organs are used as evidence in support of evolution.
Vestigial remains hark back to an earlier evolutionary stage because these vestiges are organs or parts that have ceased to exercise their original function and have become unnecessary and atrophied. Yablokov considers them examples of atavism, "organs appearing in the development of present forms and indicating the condition of their ancestors (atavus = ancestor in Latin)" (p. 244). Production of new organs has nothing to do with the matter. This is an entirely separate evolutionary issue.
The Appearance of Limbs in Cetaceans
Now that we have a fuller understanding of what constitutes a true vestigial structure, we can proceed to look for a concrete example. The cetaceans (whales and dolphins) are commonly regarded as possessing many vestiges. Of course, it is precisely these mammals that have been used by Yablokov to demonstrate the errors scientists have made in regard to vestigial structures. So we must ask, does Yablokov find any evidence for true vestigial structures in the cetaceans? Yes, he does, and much of his data is based on personal investigation.
Among the vestigial structures in cetaceans that he accepts are vestigial hind limbs. He is aware of six cases in sperm whales alone. One in particular, which was later passed on to him for personal study, he discusses on page 242.
Yablokov himself observed a remnant of a femur in a male sperm whale in the factory at Podgornyi (North Kuril Islands).
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Other investigators are also aware of this type of evidence. William King Gregory, writing in 1962 in the Encyclopedia Britannica, provided the following account.
At the request of Roy Chapman Andrews, the skeletal remains, which consisted of two bones and two heavy cartilages, were sent from Canada to the American Museum of Natural History in New York City. The specimen as found had elementary legs protruding from the body about four feet, two inches, covered with blubber about one-half inch thick. Andrews identified the bones as tibia and metatarsal, the cartileges as femur and tarsus, and published his findings:
Professor Andrews had sufficient anatomical reasons to reject the idea that the limbs were merely abnormal malformations with no reversionary significance. He concluded his research on this remarkable specimen with the following observations:
The report, entitled "Remarkable Case of External Hind Limbs in a Humpback Whale," was published in June 1921.
In 1953, Teizo Ogawa, writing "On the Presence and Disappearance of the Hind Limb in the Cetacean Embryos" in The Scientific Report on Whales Research, concluded that:
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In 1957, Tezio Ogawa and Toshiro Kamiya, writing in the same journal, reported on "A Case of the Cachalot with Protruded Rudimentary Hind Limbs."
After some discussion of the 1921 Andrews report, the authors continued:
The difference between the two cases is never essential but rather a problem of the quantity of materials for study.
In their summary, Ogawa and Kamiya stated:
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These examples of rudimentary hind limbs meet Yablokov's criteria of being nonfunctional as well as uncharacteristic of the whole population. To demonstrate their noncharacteristic nature, a report by Seiji Ohsumi is instructive.
Out of 450, he found only one example.
Other vestigial reports on sea mammals could be cited, but enough has been presented to show that these rudimentary hind limbs do exist in cetaceans and are truly vestigial. Being vestigial, they point to an earlier stage of evolutionary development. Because of this and other evidence, William King Gregory concluded in his Encyclopedia Britannica article, "that the Cetacea have been derived from terrestrial, quadrupedal placentals."
The very word vestigial comes from the Latin vestigium, which means footstep or track. Vestigial organs are traces of organs previously functional. In a sense, vestigial remains are like footprints leading us back to an earlier time when they were fully developed, a time when the ancestral animal had a significantly different body structure and a totally different way of life from the example alive today. That is what we have discovered in the case of the cetaceans.
Andrews, Roy Chapman. June 3, 1921. "Remnant Case of External Hind Limbs in a Humpback Whale." American Museum Novitate, No. 9.
Aulie, Richard P. April 1972. "The Doctrine of Special Creation." American Biology Teacher.
Camalene, Victor H. 1961. Mammals of North America. New York: The Macmillan Company, p. 631.
Dobzhansky, Theodosius. 1955. Evolution, Genetics, and Man. New York: John Wiley and Sons, p. 242.
Gregory, William King. 1962. "Mammalia." Encyclopedia Britannica, 14:751.
Kofahl, Robert E. 1977. Handy Dandy Evolution Refuter. San Diego: Beta Books, p. 102.
Ogawa, Teizo. 1953. "On the Presence and Disappearance of the Hind Limb in the Cetacean Embryos." Scientific Report, Whales Research Institute, 8:127-132.
Ogawa, Teizo, and Kamiya, Toshiro. 1957. "A Case of the Cachalot with Protruded
Ohsumi, Seiji. 1965. "A Dolphin (Stenella caeruleoalba) with Protruded Rudimentary Hind Limbs." Scientific Report, Whales Research Institute, 19:135.
Yablokov, Alexy. 1966. Variability of Mammals. Moscow: Nauka Publishers, pp. 231-246
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