halucigenia wrote:Let me grant you that mutations + natural selection produced a bird's wings (for instance) from a reptile's forelimbs. Wildly improbable, of course, but let's suppose. And feathers from scales.
Well, feathers are just modified scales, so no problem there, as they could have had uses other than flight to start with. </quote>
Now where did you get that piece of nonsense from, I wonder? Have you ever had a look at the difference between any given scale and say, a flight feather? This is an iguana, which has a load of different types of scale on its body.
Which do you fancy is the best candidate for turning into a flight feather? I personally don't see any hope, but perhaps you can tell me.
And here's a diagram of a flight feather structure:
Add to that the difficulty that there are about 10 different types of feather ON A SINGLE BIRD, your problems increase exponentially.
asyncritus wrote:, and endothermic metabolism from ectothermic metabolism. Theropod dinosaurs could have been endothermic before they evolved flight so, no problem there either.
Could, could, could... Sure pigs can't fly?
asyncritus wrote:Not to mention the entirely new lung structure, in which air enters the lung on
exhalation rather than on inhalation.
again, something that could have evolved in theropod dinosaurs prior to wings and flight, so, again there is no problem there either.
No, I'm not having that either. Here are two diagrams of the structures involved:
Honestly, H, can you see any possible way for the left type lungs to become the right type lungs? I can't see it myself, but maybe you can. If you can't, then you're admitting that brainless, blind, and purposeless mutation plus natural selection is much more intelligent than we are. Well, you are maybe!
asyncritus wrote:All that by the magic of waving the old Random Mutation Selection wand. (Has common sense completely deserted your halls???)
No magic required, all of the examples that you have provided so far could have evolved prior to the evolution of wings and flight. If that is what you are getting at.
But why should they do so? Surely you're not saying that an organ/metabolism/whatever else can evolve IN ADVANCE of being needed. Somebody said words to the effect that something can't evolve in the Cambrian because it might be of use in the Jurassic. So true.
asyncritus wrote:Now the questions:
Bird hatches out from reptile's egg, as Goldschmidt suggested, because he knew that there's no other way for this to happen!
Why?
Why is there no other way for this to happen?
To be perfectly honest, when I add up the vast differences between a bird and any given reptile, the impossibility of one evolving from the other becomes positively gargantuan. I've indicated some of the difficulties above, and I'm sure that even you can feel the force of some of those points.
Why can birds not have gradually evolved over time from reptilian ancestors via theropod dinosaurs?
They could evolve from fish as far as I'm concerned. The question I'm asking is a deeply fundamental one.
For A to evolve into B, there are major instinctual questions that need some sort of evolutionary answer. For any function, not existent in A, but existing in B, there MUST be pre-existing instincts powering that function, which have entered the genome. (The whole question is raised, expanded and answered in the book 'How does instinct evolve'. You'll find it on google somewhere.)
Why can feathers not have gradually evolved in this lineage which provided utility in ways other than flight – insulation or display for example?
Are yo asking me why a blanket can't evolve into a wing?
Why can an organisms’ metabolism not change from providing little excess body heat to providing more and more body heat over time?
Because the physiology of an ectotherm is very, very different to an endotherm. The amount of heat required to support an andotherm is wildly different to that required by an ectotherm.
Why can lungs not be modified by random mutation and natural selection from a simple air sac to one with flow through functionality?
Because any of the changes required in that change would be immediately fatal. I might as well quote Denton's remarks on the subject for you. You know he's an evolutionist, but not the usual starry-eyed variety.
Just how such an utterly different respiratory system could have evolved gradually from the standard vertebrate design is fantastically difficult to envisage, especially bearing in mind that the slightest malfunction leads to death within minutes.So one mutation affecting the structure of the lung meant death immediately. One mutation producing a hole in the bottom of the lung meant death. So where do you go from there?
Just what do you think actually prevents these things from happening.
And, remember, personal incredulity is not a valid argument.
I don't argue from incredulity. I make inferences to the best explanation, something that all science does all the time.
asyncritus wrote:1 What could the new bird do with the brand new flight apparatus? After all, he's still a reptile in his head. Can you see it? 'Duhhhh! What the hell do I do with these things'? Jumps off cliff. THUDDD! End of bird evolution.
Do we really have to go there again? You sound like you have been to the Stevebee School of argumentation.
No one, except creationist straw man arguments, propose that an organism suddenly appeared with brand new novel adaptions like a full set of flight apparatus within a single generation.
Richard Goldschmidt certainly thought so, or he would never have proposed his Hopeful Monster theory. He knew the facts (such as I've been outlining above) and couldn't produce any kind of sensible explanation. I can't remember reading anyone producing a proper account of how it could have happened, so maybe you can point me in the right direction toward one of them.
You see, if the whole thing didn't appear in one go, then of what use was the intermediate? Szent-Gyorgi proposed his negentropy theory, but the new Law of Asynctropy takes the whole thing to a new level. It says that
Every one of the functions of life depends on a POWERING INSTINCT. If the powering instinct is not present or available, THEN THE FUNCTION ITSELF IS ABSENT OR IMPOSSIBLE even if the necessary organ is present.Which is a pretty profound and far reaching statement of fact. Give it some thought.
asyncritus wrote:It requires empowering flight instincts - or it couldn't get off the ground, no matter how good the wings etc may be. Think of a fighter plane with an untrained administrative clerk at the controls. Disaster on the way? You bet.
Not all flight ability is instinctual, have you never seen young birds on nature documentaries stretching their wings and learning how to fly. Again, no one except creationists’ straw man arguments propose that an organism suddenly appeared with brand new novel adaptions like a full set of flight instincts within a single generation.
Sure I've seen them doing that. We all have, I'm sure. But I could spread my wings till the cows come home, and all I'd succeed in doing is breaking my neck every time I jumped off a roof.
THE ABILITY TO LEARN HOW TO FLY
MUST BE THERE, or the wings are useless. It's that instinct again.
Remember if Critter A learns how to fly without breaking it's neck, then it CANNOT pass that information down to its offspring who have to start from scratch again - otherwise you're in Lamarckism again. (But I see Dawkins trying to sneak it in by the back door again! Why, because he knows just how ridiculous his theory really is).
so
2 Where did the instincts come from
They evolved in tandem with the flight apparatus, slowly, over time.
Don't you see how hopless (
} that proposition really is? Bird A (with 1 wing) flaps, is spotted by a predator, gets eaten and the whole thing has to start again.
Bird B (with 1 wing) flaps, is eaten by a predator..... la de da.
I don't see things progressing very far, do you?
asyncritus wrote:3 And how did they enter the genome?
How do any behaviours originate and evolve, there’s nothing magical that has to “enter” the genome, behaviours and the ability to learn do have a genetic component which can be modified and change over time just like any other trait under genetic control.
Again, here's Bird A who's got the equipment, but can't fly. He takes off, narrowly avoids breaking his fool neck, survives and reproduces. How does the information regarding flight enter the genome? Answer, it can't.
But that information MUST enter the genome somewhere along the line - otherwise birds can't fly, ever. So where and how? I read somewhere that some Chinese palaeontologist found the most ancient bird fossils,
and the bird could fly. Well it got those flight instincts somewhere. But where?
asyncritus wrote:Remember, Lamarckism is dead, and cannot make any contribution here.
Yes and no one, except creationists’ straw man arguments propose that any Lamarckian process is required for instincts to arise and evolve.
You are forced to do so, that's for certain, much as you may object.
Here we are again:
A (can't fly) --------------X---------------> B (can fly)
How many X's do you want? How many intermediates between A and B? It matters not. Somewhere in that chain, one of them learned to fly AND PASSED THE INFO DOWN TO OFFSPRING.
Unless of course, you want to say that suddenly, a whole flock of fliers appeared. Which is merely another word for creation.
As I see it, you are on some pretty painful horns here. The instinct question, detailed in
How Does Instinct Evolve, will kill off evolution theory once this new development of it becomes known.
But nice to see you here and it’s nice to have a new chew toy.
by 
