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| Archaeopteryx, the fossil bird found in rock supposedly 150 million years old. Palaeontologists now agree that Archaeopteryx is not the ancestor of modern birds. |
BIRDS OF A FEATHER
This is particularly true of the supposed development of flight. According to evolution, flight has developed in at least four independent situations: in birds, insects, flying mammals and flying reptiles (now extinct). Each separate development would have involved numerous transitional forms, subtly changing over millions of years, but no such fossils have been found.
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| Archaeopteryx, the fossil bird found in rock supposedly 150 million years old. Palaeontologists now agree that Archaeopteryx is not the ancestor of modern birds. |
Instead there are just a few fossils which are alleged to represent a transitional form. Probably the most notable is Archaeopteryx, a fossil bird claimed as a link between reptiles and birds. The pictures show the fossil and an artist's reconstruction. It is bird-like in that it has wings and feathers; but hooks on its wings, teeth in its beak, bones in its tail and the absence of a prominent breastbone are taken as reptilian features.
Archaeopteryx, the fossil bird found in rock supposedly 150 million years old. Palaeontologists now agree that Archaeopteryx is not the ancestor of modern birds.
Nevertheless, there are true birds living today with some of these features. The young hoatzin bird of South America has claws on its wings, as do the turaco and ostrich in Africa. Modern birds do not possess teeth but some fossils that were undoubtedly true birds, do. But the greatest evidence against Archaeopteryx is that not long ago, in the very same rock strata in which it was found, a fossil of a true bird was unearthed.35 Thus, Archaeopteryx could not be the progenitor of true birds for they were already in existence. Archaeopteryx, although admittedly rather odd, was a bird, not a missing link with reptiles.
Doubts are now cast upon Archaeopteryx as a ‘missing link’ between reptiles and birds. In 1985 University of Kansas’s palaeontologist Larry Martin admitted that Archaeopteryx is not ancestral to any group of modern birds. As one modern biologist has said: ‘The almost perfect link between reptiles and birds has been quietly shelved, and the search for missing links continue as though Archaeopteryx has never been found’ 36
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| Diagram of the avian lung (top) showing how air passes through in a continuous stream, in contrast to the mammalian lung that has an in-and-out flow. |
What is fatal evidence against the reptile-to-bird theory is the profound difference in the lungs of the two creatures. In reptiles, as in humans, air is drawn into the lung and is then breathed out the same way as it came in. Birds do not have this in-and-out method. Their lungs are open-ended, the air coming into the lungs by one tube, which divides into smaller ones. These then unite again to form a tube by which the air leaves. Thus there is a continual one-way flow of air through avian lungs. This also necessitates the presence of many other related structures for this method to function.
If birds have come from reptiles how could such radical changes have occurred (by chance mutations, remember!) over millions of years. How would the creature survive whilst the airway direction was being so radically altered? Would chance at the same time produce the other essential altered respiratory structures essential for the bird's survival? These are the sort of questions for which evolution has no reasonable answer.
Reference
36 J Wells: Icons of Evolution: Science or Myth? 2000, pages 116,135.