ARE THERE VESTIGIAL ORGANS? One of our readers asks: “I read an evolutionist blog the other day on creation science arguments. One was on vestigial organs vs genetic loss. He said that creationists say there are no vestigial organs (which is true), but there are examples of things that do not fully function i.e. beetles of the same species; some have wings and some don't. Another example is the earwig. Some earwigs have wings but as far as I know they don't fly. They stay in moist undergrowth and under rocks etc.
The evolutionist said that creationists mince words when really organs rendered useless by genetic loss and vestigial organs are the same thing – useless. This is something I want to address. Can you succinctly explain the difference or refer me to a book or article that gives an explanation as to the difference?”
ED.COM. The short answer is that most of what evolutionists have called vestigial (organs which have supposedly lost their function such as the classic appendix) have turned out to be fully functional, and hence no use to the case for evolution. At the opposite end, in spite of what is presented in many creationist writings and websites, there are partly or fully vestigial organs or body structures that are at present defective in structure or function such as the world’s only nocturnal ground dwelling or flightless Parrots in New Zealand. But in every case they turn out to be wonderful evidence of change, but not of evolution – the change involved is always degenerate. The long answer is the rest of this Evidence News.
FLIGHTLESS BIRDS: Live Science writes: “Ostriches and cassowaries are among several birds that have wings that are vestigial. Besides the cassowary, other flightless birds with vestigial wings are the kiwi, and the kakapo (the only known flightless and nocturnal parrot), among others. In general, wings of a bird are considered complex structures that are specifically adapted for flight and those belonging to these flightless birds are no different. They are, anatomically, rudimentary wings, but they could never give these bulky birds flight. The wings are not completely useless, as they are used for balance during running and in flagging down the honeys during courtship displays.”
In May 2008 New Scientist wrote “The existence of something as spectacularly de trop as the ostrich wing is only a problem for those who believe in an intelligent designer.”
ED. COM. The best comment on the ‘vestigialness’ of ostrich wings comes from a letter to New Scientist by Sibbele Hietkamp, an ostrich farmer in South Africa, who wrote: “Laura Spinney describes ostrich wings as ‘spectacularly de trop’ (17 May, p 42). I have kept ostriches for 18 years and can testify otherwise.” He goes on to describe how ostriches use their wings for many important functions: thermoregulation; providing stability when running and enabling rapid right angle turns; courtship displays and stability while mating; warning signals and other communication; nest building; and providing shade and shelter for young. (New Scientist letters 21 Jun 2008, p24).
Sibbele Hietkamp’s observations also remind us that practical observations and experience from those who work with living things or in a particular environment are more of use to science than the beliefs of journalists and academics who are not. Even though they can’t fly ostriches are particular efficient runners and are able to function well in a variety of environments.
If you consider the overall anatomy and physiology of the ostrich, rather than just its wings, you will see that it is a functioning creature that works well, so the New Scientist quip against intelligent design wasn’t very intelligent.The wings of other large flightless birds, e.g. emus, cassowaries, penguins, rheas, fit into the same category as ostrich wings – an extreme variation of wings, but still functional and useful structures that are part of a fully functional creature whose fossils show no evidence the bird has ever flown and perhaps was never meant to fly – but which seem very intelligently designed for running, cooling, mating and protecting young.
There are some birds that seem to have lost the ability to fly due to defects in their wings but they have survived in a small protected environment, e.g. flightless cormorants in the Galapagos Islands or the Titicaca Flightless Grebe. These are usually classified a separate species within a genus of similar flying birds, suggesting that they are descended from a flying bird that suffered some genetic defect in the past. Because the defective birds find it easier to mate with each other, they soon become genetically isolated and effectively become a separate species. The wings of these disabled birds could be called “vestigial” but this loss of function is not evolution – it is degenerate loss, which is the opposite of evolution. The kiwi of New Zealand seems to be an extreme example of loss. It has small wings, but no wing muscles, which means it has no muscle covering over its chest and is easily killed by dogs and other animals. It has only survived by living a secluded nocturnal life in forests where there were no predatory mammals before humans accompanied by their cat/dog pets came to live in New Zealand.
Penguin wings are sometimes called vestigial, but even though they are flightless, penguin wings are well suited for their aquatic lifestyle. Their wings function as efficient flippers with powerful muscles and that enable them to move through the water with a movement that is similar to flying and the abundant fossil record of Penguins shows they were once much larger but show no evidence of ever having larger wings. (Ref. ratites, Apteryx, Aves)