To: Aquinasfan
Things like wings don't just crop up over night. They are modifications of existing structures. They start out as something else and gradually change to accommodate new uses. For instance, the wing started out as a therapod foreleg. Recent research shows that early bird-like dinosaurs may not have developed flight or needed a full-fledged wing right off the bat. Flapping the arm/wing assisted the critter in climbing trees to escape predators. There was not need for a full-fledged (no pun intended) wing. Small modifications allowed the animal to launch itself at the tree from a little farther away, and then a little bit farther, and so on. At no point was any new system being introduced -- there were simply modification of existing structures. That is why you'll never see a skunk with gills, or anything like that. You will not see a radical bad mutation in the fossil record for the same reason -- only small changes are made in the organism and if the small changes decrease the organism's chance for survival it will be weeded out long before it gets out of hand.
583 posted on
03/18/2002 6:44:49 AM PST by
Junior
To: Junior; Aquinasfan
Your postings to each other appear to be giving some guidance to those of us who recognize we're generally talking past each other. For instance, evos have been posting links to (and in the case of replies to G3K, photos of), transitional fossils. Now Aquinasfan appears to clarify why none of these transitional forms appear to him to be convincing: He's looking for a skunk with gills, or something of that nature.
Evolutionary theory doesn't claim there was one, and when it speaks of "transitional forms," it's speaking of incremental change, even in the case of punk eek. Junior's doing a pretty good job laying out what is out there and why we think it's important. It also needs to be noted that something like a skunk is too far removed from anything that has gills for there to be something "unsuccessful" directly in between them. The unsuccessful ones don't get to reproduce to the point where their offspring would be around to pass on the mistake (i.e. the skunk's gills). Ditto "a lion with wings," although I think the Abyssinians may have worshipped something like that. But no one thinks a wing appeared suddenly, fully formed and functional.
588 posted on
03/18/2002 7:36:39 AM PST by
Gumlegs
To: Junior
Things like wings don't just crop up over night. They are modifications of existing structures. They start out as something else and gradually change to accommodate new uses. For instance, the wing started out as a therapod foreleg. I've heard the stories/theories. The only problem is the lack of these half-formed structures in the fossil record. That's what "fully-functional, integrated organisms" is all about. Every fossil that I've ever seen shows a creature that is a functioning whole. That is, all of its bodily systems (nervous, musculoskeletal, circulatory) correspond to its morphology and its purpose in its biological niche.
Similarly with the "just so" stories of eye development. The vision system of a planaria is suited for a planaria. The vision system for a squid is suited for a squid. And the vision system for a human being is suitable for a human being. None of these vision systems seems to be of "lesser or greater" development than the rest of the organism.
If every creature descended from some other creature, then the fossil record should be full of creatures with features that are "lesser or greater" than its other bodily systems/features/functions.
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