>Randy wrote:
>
><<I was wondering if you could explain to me how fish which had gills and no
>lungs could develop lungs loose their gills and still survive.>>
>
>That's the $64,000 question!
>
>To buy the evolution story, you have to believe:
>
>"The evolution of air-breathing organs occurred several times [!!] within
>different lines of bony fishes. These organs include vascularized swim
>bladders, parts of the digestive tract, specialized compartments to the gill
>chamber, and in dipnoans, lungs." [Kardong, Vertebrates, pg. 435]
>
>This is hard to, er, swallow, so the official story is that lungs were
>"pre-adaptive." That is, they did not evolve in anticipation of life on land,
>but as supplements to gills when oxygen in water became inadequate.Then, when
>the little fellas were ready to go onto dry land looking for worms, voila!
>They had lungs all ready for them!
>
>Convenient, eh?
>
>And remember, it is not just the lungs. It is a host of adaptive changes
> that have to be accounted for:
>
>"The major problems with life on land relate to weight and structural support
>as much as to the physiology of breathing air. A fish is buoyed up by the
>water and its body weight may be effectively zero. On land, however, the body
>as to be held up by some form of limbs, and the skeleton as all the internal
>organs have to become structurally modified in order to cope with the new
>downward pull of gravity. The backbone of a fish is adapted for the stresses
>of lateral stretching and bending during swimming, but the main forces to
>which a tetrapod is subject are caused by gravity. The vertebrae and the
>muscles around the backbone have to become modified to prevent the body from
>sagging between the limbs. The mode of locomotion of a tetrapod on land is
>generally different from that of a fish in water." [Benton, Vertebrate
>Palaeontology, Chapman & Hall 1990, pp. 46-47]
>
>Once again, a whole host of changes had to occur simultaneously. Like a
>protective pectoral girdle and new skin. And bone! This is a real corker:
>
>"It is obvious that the creation of bone required not one but a whole burst
>of mutations, all integrated to a single end--an incredible thing to happen
>by >chance even if nothing else had been going on." [Taylor, The Great
> Evolution Mystery, pg. 56]
>
>So in answer to your question, Randy, no one can explain it.
>
>Jim
>
>
>
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm