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Something fishy about lungs


It is well known that creatures which live permanently in water generally breathe through gills, not lungs. The lungfishes, which are able to survive long periods when their watery habitat dries up, are regarded as a peculiar exception.

Most people, having been conditioned by evolutionary texts, believe that the only other permanent waterdwellers to have lungs are the whales and porpoises. These are believed to have descended from land creatures which later evolved back into the sea. The scenario goes like this: fish (no lungs) → [out of sea] → amphibian (lungs) → reptile (lungs) → land mammal (lungs) → [back to sea] → porpoise (lungs)

Most fish have a gas-filled swimbladder, which helps their flotation. For a long time it was believed that this swim-bladder was a logical ‘first step’ towards the later development of lungs as vertebrates conquered the land. (A conquest existing only in the realm of fantasy, by the way, not demonstrated by fossils.) No one disputes the fact that swim-bladders and lungs develop from the same basic tissues, and from the same type of out-pouching of the foregut. In the evolution model, this is interpreted in terms of common ancestry; in the creation model, in terms of the same Grundbauplan (basic building plan), with creative variations on the same theme.


So how do these neat evolutionary stories square up with reality? The first awkward fact, usually not mentioned in high school evolutionary texts, is that there are actually many modern species of fish (not mammals, but real fish) which have lungs as well as gills. For instance, among the so-called ‘higher’ bony fish (the teleosts) many species of electric fish have them. Of the chondrostei, the so-called ‘primitive’ bony fish, the Polypterus is so dependent on its paired lungs that this fish can drown if prevented from surfacing.

An even more bitter blow for evolutionists (again seldom seen in basic texts) is that fossil evidence has come to light forcing a 180-degree reversal in the ‘swim-bladder to lung’ story. Lungs appear to be much more ‘ancient’ than swim-bladders, so by this reasoning, lungs must have evolved into swim-bladders!

The renowned comparative anatomists Romer and Parsons tell us in their book The Vertebrate Body (Saunders Co., Philadelphia, 1978, p. 329) that there is evidence that the most ancient (according to evolutionary tenets) placoderm fishes already had functioning lungs, which would mean that all ‘primitive’ jawed fish had them. The diagram with its captions shows the distribution of lungs among living and a few fossil species of fish.

All of this is of course consistent with the simultaneous creation of all water-dwelling creatures on day five of creation week, with variations on the Grundbauplane. Whether endowed with gills, lungs, or a combination of both, all fish, living or extinct, appear to be (or have been) well equipped for the requirements of their way of life.

The ‘obvious’ evolution of lungs from swim-bladders turns out to be a myth. In addition, a literal evolutionary- chronological reading of the fossil record shows that evolution must have had remarkable foresight. In spite of the fact that lungs are not needed for survival (fish being able to cope well with gills) they appear and are prevalent among fishes at least 100 million years (on the alleged evolutionary time-scale) before their (imaginary) migration to the land. How wonderful of evolution to develop, all by chance of course, such a ‘test pattern’, ready to be taken out of mothballs when required. No wonder such awkward facts are not generally highlighted when presenting impressive-sounding evolutionary ‘just-so’ stories.

Joachim Vetter, Dr. Med.hab., Ph.D. has medical and biological qualifications, and is a frequent contributor to the Swiss/German creation-oriented magazine Factum. His special interest is the comparative anatomy of fossil and recent forms.  Return to top.

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