But, as with many such “proofs” of evolution, the problem lies with the assumptions. To say that a biological structure has reduced functionality, we have to take several things for granted.
First of all, one would have to know the level of functionality of the organ or structure in the supposed ancestral organism. Second, we would have to know that the structure in question has minimal or no use in its present form. However, of the 180 or so organs that have been called vestigial in humans, all have been shown to have function. Last, and most importantly, for this type of argument to be used, one has to assume evolution to be true in the first place! So, if vestigial organs are obviously left over from our evolutionary heritage, then evolution must be true. Here evolution is assumed to be true in order to make the argument. This is a logical fallacy, called begging the question.
