Actual fossils of the impossible thing.
Posted on 01/30/2002 8:06:07 AM PST by Gladwin
The present consensus is that feathers did not evolve directly from scales but are a novelty -- probably a cylindrical follicle producing a conical papilla that evolved into a branched structure. The biochemistry, 3-D structure, and genes are different for scales and feathers. Birds retain scales on the bottom of their feet that are chemically identical to reptile scales. Bird scutes, claw-sheathes, and beaks are chemically identical to the feathers. The genes for feather proteins are located adjacent to and in the same relative position on a bird chromosome as the scale genes in the Crocodile, for example.
Feathers evolved originally as insulation. Exaptation for flight occurred much later. A recent example of exaptation is the use of the wings as glare shields by the African Black Heron. Clearly the wing structure evolved without any anticipation that it could be used for the purpose of shielding a patch of water from the sun, yet that is what the bird uses it for as it feeds in the shallows.
Antifunctional? I love it when creationists make up words to sound like they know what they're talking about.
How would a set of gradually improving feathers or bones be "antifunctional" every step of the way towards flight?
They don't need everything to fly, they just need everything on your checklist in order to fly well. The idea is that they flew poorly at first, and eventually got better at it.
And the idea that evolution has been somehow disproven or dscredited is ludicrous.
No, males and females share most of the same DNA. In our case, we have twenty-three pairs of chromosomes. Males and females have essentially identical DNA in 22 of the pairs, the other pair is made up of X- and Y chromosomes.
You need everything on the list just to fly poorly. Picture some bird with half-formed flight feathers or with the flight feathers but not the system which lets them rotate open like venetian blinds on upstrokes. He wouldn't get off the ground.
dinnertime and the end of this as a new species.
Take for example mules, half-horse and half-donkey.
If a man has a minor (or even major) mutation, he may still be able to mate with a "normal" woman and produce viable offspring.
Simply--how can an organism survive without lungs when it is busy evolving a circulatory system? You're seriously telling me that the organism can do both at once, along with the nervous system, immune, sexual...all at once?
To which I'm told--you ain't no scientist.
Evolution, however, is a fabulous means of description, without its religious dogma. It is so effective at categorizing and classifying that I think it must have assumed some other proportions in the minds of the witch doctors...
Quite a few. Most evolutionists think it would have taken millions of years to make leaps like this.
And what about the inbetween mutations? Where are they? There would have to be some (actually many) around.
They could have died off if they couldn't compete with the newer animals. A modern bird would be able to fly much, much better than a half-bird half-lizard creature. The half/half creature would die out if it couldn't compete with birds (if predators could kill it more easily than a modern bird, it would die out, and eventually become extinct).
Remember, too, that the jenny (the offspring of a horse and a mule) is sterile.
Yes, sometimes mutations preclude animals from mating, just as sometimes mutations leave humans sterile. The thing is, the sterile ones die off very quickly, whereas the fertile ones are able to keep passing on DNA.
Better tell that to the bats, bees, honey gliders, flying squirrels, flying fish, pteradactyls, pteranodons, etc., etc. There is even an arboreal snake that does a pretty good job of simulating flight. With your argument the Wright Brothers shouldn't have been able to fly until they were provided with a Pratt & Whitney Jet Engine and a Boeing airframe.
Better tell that to the bats, bees, honey gliders, flying squirrels, flying fish, pteradactyls, pteranodons, etc., etc.
Irrelevant. We're talking about evolving into a flying bird and a gliding squirrel or lizard is not remotely close to a plausible 90% point for getting to flying bird status. For a bird or anything trying to evolve into a bird to fly, even badly, all features would need to be in place.
You could "fly" yourself if you wanted to. Especially if you first climbed a tall tree and relied on gravity for acceleration. At least you could accomplish a steep dive without any wings, feathers, hollow bones, enlarged respiratory system, or big breast muscles. Because you don't know what the first proto-bird looked like it is a bit presumptuous of you to assume that it could not do at least as well as you as a "flyer" of sorts. This proto-bird may have been very well adapted for steep dives, perhaps it hunted this way. Perhaps it had sufficient control surfaces to adjust its trajectory while diving. It really doesn't take very much to begin to fly.
Now to your second mistake. No living thing "tries" to evolve. Becoming a bird is what happened to the progeny of those collections of breeding individuals for whom survival depended on falling without damage which led to diving with accuracy which led to gliding for distance which led to soaring aloft which led at last to flying. The best at each stage tend to leave more progeny than the less accomplished and the process accelerates when a species moves to an unoccupied niche (i.e., the sky is the limit).
Very small changes in gene expression (ie one non-functioning gene) can have large consequences. For example, whether a baby develops male or female genitals is determined by three chemicals: anti-mullerian hormone, testosterone, and 5-alpha-reductase. If one of these chemicals is not produced then the baby will have problems. For example, genetic male babies who cannot produce 5-alpha-reductase due to a genetic mutation do not develop a penis and scrotum.
Likewise, it's possible that a small genetic change in reptiles could produce scales that look like feathers. I don't know enough about reptiles and birds to say for sure.
Actual fossils of the impossible thing.
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