El apendice

Papers

Do any vestigial structures exist in humans?
Jerry Bergman
The standard definition of ‘vestigial’ is an organ that once was useful in an animal’s evolutionary past, but that now is useless or very close to useless. The list of vestigial organs in humans has shrunk from 180 in 1890 to 0 in 1999. Evidently to salvage this once-critical support for evolution, a new revisionisticdefinition of a vestigial structure is now sometimes used. This definition involves the idea that a vestigial organ is any part of an organism that has diminished in size during its evolution because the function it served decreased in importance or became totally unnecessary. This definition is problematic because it is vague and would allow almost every structure in humans to be labelled as vestigial.Classical definition of vestigial

The question, ‘Do any vestigial organs exist in humans?’ (or any other life form for that matter), first requires a definition of ‘vestigial’. The most common definition of a vestigial organ throughout the last century was similar to the following: ‘Living creatures, including man, are virtual museums of structures that have no useful function but whichrepresent the remains of organs that once had some use (emphasis mine).’ 1 The authoritative reference The Evolution of Life 2 defines a vestigial organ as one ‘which has lost its function in the course of evolution, and is usually much reduced in size’. The standard anatomy authorities usually define a vestigial organ as referring to a once-useful organ that now is useless or very close to useless.Dorland’s Dictionary defines the term vestigial as ‘a vestige, trace or relic’, and defines the term as ‘the remnant of a structure which functioned in a previous stage of a species [evolution]’.3 Churchill’s Dictionary defines vestigial as an organ that has ‘no obvious function’, and notes that the word vestigial derives from the Latin vestigium, ‘meaning footprint, imprint, track, trace’.4 Astandard dictionary of biology defines the word vestigial as follows: ‘An organ that is functionless and generally reduced in size but bears some resemblance to the
CEN Technical Journal 14 2000 14(2)

corresponding fully functioning organs found in related organisms. Examples include the wings of flightless birds, the limb girdles of snakes, the appendix and the ear muscles of humans, and the scaleleaves of parasitic flowering plants. The presence of vestigial organs is thought to indicate that the ancestors of the organism possessed fully functioning organs ... .’ 5 Asimov1 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 Asimovclaims 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. The above definitions of vestigial organs all focus on organs that once had an important function in an animal’s evolutionary past, but have virtually no function in the animal today. The following example is typical of how thevestigial organ argument was used in textbooks in the past as a ‘proof’ of evolution: ‘Useless Organs Prove Evolution. Science has piled up still further evidence for its case. It has found a number of useless organs among many animals. They have no apparent function and must therefore be a vestige of a once useful part of the body. A long time back these vestigial organs must have been important; nowthey are just reminders of our common ancestry. One example is the vermiform appendix which not only is utterly useless in human beings but which often causes great distress [emphasis in original].’ 6 This definition still is commonly used. One of the most popular modern life science textbook writers defined

Once claimed by evolutionists as a vestigial organ, the appendix has many known...