rationalskepticism.org

asyncritus wrote:HI H,
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.

Why on earth would you jump straight to flight feathers when no one thinks dinosaurs did? Something resembling down, maybe.

asyncritus wrote:Add to that the difficulty that there are about 10 different types of feather ON A SINGLE BIRD, your problems increase exponentially.

Start with any kind of feather, then diversify. Not so astonishing when you're not advocating some cartoon version of evolution where they all spring forth fully formed for their future functions.

asyncritus wrote:Could, could, could... Sure pigs can't fly?

I think the point is that there is no good reason to believe those features didn't appear prior to flying. In fact, the pneumatized vertebrae of therapod dinosaurs when they are preserved in enough detail indicate their lungs were similar to the lungs of birds, and consistent with continuous flow-through breathing (O'Conner and Claessens).

asyncritus wrote: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!

I'm sure that brainless, blind, and purposeless mutation plus natural selection is much more intelligent than any of us are, given millions of years to blindly explore 'possibility space'. We're still playing catch up on understanding the results of evolution.

asyncritus wrote: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.

Very true. But an endothermic metabolism and efficient breathing mechanism have advantages of their own, whether you have wings or not.

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!

At no point would the offspring of an animal be a different species (or subspecies, or race) from the parents. It will be only slightly different from the parents, but if that slight difference gives it a slight advantage, natural selection will tend to conserve the change.

asyncritus wrote: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.

If all the steps are possible, and there's enough time for the steps to happen, it's not impossible.

asyncritus wrote: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.)

At no point is there suddenly a novel function. Flying squirrels and lemurs are gliders who clearly wouldn't have to adjust their instincts too much to transition from leaping to gliding in small steps. After all, at first a small gliding membrane would only let you leap a little farther. Their brains would have the opportunity to co-evolve the instincts to take better advantage of gliding capability. It's not difficult to imagine the descendants of one of these animals transitioning gradually from gliding to true flying in baby steps that let its instincts keep up.

asyncritus wrote:Are yo asking me why a blanket can't evolve into a wing?

More like why fur can't evolve into quills, or down into true feathers.

asyncritus wrote: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.

But the amount of heat required to support something that is 51% endotherm is not much different from the amount of heat required to support something that is 52% endotherm.

asyncritus wrote: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?

A hole in the bottom of the lung leading to an air sac would not only not mean death, it could be advantageous. Air sacs are known to have developed in chameleons, snakes, some lizards, btw. The development of flow-through lungs would be easily survivable if they went through a mixed stage. We have the amphibian's three-chambered heart between the fishy two-chambered one and mammalian four-chambered heart to illustrate how we got from two chambers to four without keeling over. We don't have that intermediate stage to illustrate the development of avian lungs, but it isn't THAT hard to come up with a scenario where the animal has lungs that can do both bi-directional and one-directional air flow. Birds HAVE some bi-directional air flow.

asyncritus wrote:I don't argue from incredulity. I make inferences to the best explanation, something that all science does all the time.

So what's the best explanation?

asyncritus wrote: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.

I'm sure a branch hopper would see immediate benefit from being able to leap a few inches farther thanks to feathers already present on its forearms getting a little longer in the right direction.

asyncritus wrote:Richard Goldschmidt certainly thought so, or he would never have proposed his Hopeful Monster theory.

That was in the 1930s, right? If only we had learned anything more about evolution in the last 70 years.

asyncritus wrote: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.

One thing I know is that the 'hopeful monster' idea was controversial at the time and has been discarded since.

asyncritus wrote:You see, if the whole thing didn't appear in one go, then of what use was the intermediate?

A lung capable of both bi-directional and one-directional air flow would be more efficient than a lung not capable of one-directional air flow at all.

asyncritus wrote: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.

Google returns no results for the term 'asynctropy'.

asyncritus wrote: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?

If only evolution proceeded in tiny steps so that a whole new set of instincts wasn't needed for the variety of novel functions that appear out of nowhere. Oh, wait.

asyncritus wrote:THE ABILITY TO LEARN HOW TO FLY MUST BE THERE, or the wings are useless. It's that instinct again.

To leap an inch farther thanks to a rudimentary gliding surface doesn't take new instincts. However, any instincts that let the animal get another inch by using the surface it has more efficiently would certainly be conserved. And so on.

asyncritus wrote: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).

If Critter A has a minor change in its brain wiring thanks to genetic variation that makes it glide slightly more efficiently, that mutation or gene combination or epigenetic configuration will tend to be preserved. By the time you get to critter Z+n, you have fully developed wings and the instincts to go with them because at every single point the offspring with the genetic variation likely to be conserved was the same species as the parent.

asyncritus wrote: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.

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

Therapod A with slightly longer feathers on the back of its forearms manages to jump an inch farther than its parents could and escapes the predator (or catches insects with 3% less effort or whatever the survival advantage actually was), surviving to pass on its slightly longer forearm feathers. And yes, if it gets eaten before reproducing, it wasn't the ancestor of modern birds and some other therapod with slight longer forearm feathers had that honor. Not so implausible once you clear away the straw.

asyncritus wrote: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.

I suppose the cartoon version of evolution with hopeful monsters and crocoducks might be challenged by it, as it is by pretty much anything.