That's because you really don't know what evolutionary theory says. Two key points:
1. Evolution never produces something out of nothing. It's always a modification of something that was already there.
2. Preadaptation is an important element in evolution, and has been since Darwin.
You are begging the question about whether evolution did take place. That is not allowed. You are required to prove that it did, and so far all you have managed to do is beg the question.
I've asked you several times to spend a little effort to learn what biology is about. It would be very useful to you.
Perhaps you should learn a little bit about logic and argumentation, instead of question begging all the time. I repeat, you have tp prove that it did occur, not make the silly and unwarranted assumption that it did.
No. For example, the forelimbs of bipedal dinosaurs, particularly those with feathers, were very useful of organs of balance and control. The feathers along with flapping movements, permit control and balance. We see this in ostriches today. So flying was an elaboration of something already in place.
Several points here.
1 Did dinosaurs have feathers - flight feathers? Or were they all Archaeoraptor-type fakes?
2 Control and balance do not constitute flight. Ostriches are therefore inadmissible as evidence of anything, since a. they cannot fly, and b. lack a keel, to which the large flight muscles are attached, as you may or may not know.
Why introduce control and balance, when they are irrelevancies as far as being able to take off are concerned? Easy, you have nothing constructive to say on the subject of the origin of flight itself. No ostrich can take off, so I again point out the irrelevancy of your 'argument'.
And in case you haven't noticed, the wing of a bird is not simply a forelimb with feathers attached. It is a properly shaped aerofoil. Do you know what that is? Perhaps you'd like to tell us, and then account for how a reptile forelimb became a correctly shaped aerofoil.
Barbarian observes:
Bipedal dinosaurs, as you learned, would use their forelimbs as organs of balance in running.... So the motions were already there, used to a slightly different purpose.
As I said, you need a bit of training in logic.
We have
1 bipedal dinosaurs
2 with balancing forelimbs
3 which, like ostriches, run.
The subject of the origin of flight itself, is conspicuously absent from anything you have yet written, apart from the quite foolish claim that "ostriches use their rudimentary wings to control their movement while running, in the same way that flying birds control their flight."
Nice try - but what is the connection between flightless ostriches and flying birds? Answer: none.
Running, once more, is NOT flying - but all this biology you think you know should have taught you this by now. Clearly it hasn't, or maybe you don't know the difference, and weren't taught it in whatever courses you went on.
So let me help you.
When running, the creatures' feet are ON THE GROUND, only leaving it briefly. When flying, the birds' feet DO NOT TOUCH THE GROUND, for considerable lengths of times as you should know by now. If you don't, I can recommend a few good textbooks on the subject if you like.
So running and flying are fundamentally different methods of locomotion - flying being by far the more technical and advanced method. Now can we stop this foolishness about a flightless bird being able to show that balance and control are somehow linked to flight? If it can't fly, then it cannot teach a flyer how to fly.
Simple isn't it?
Well, let's take a look...
... They found the ostriches used wings as sophisticatedair-rudders for rapid braking, turning and zigzag maneuvers. Experiments thatplaced ostrich feathers in streams of air showed they could indeed provide lift,which would come in handy for animals that did fly.
So we have wings which are 'rudders', 'brakes' 'maneuvering equipment'. I see nothing there about FLYING EQUIPMENT. But I do see something quite stupid there about 'coming in handy for animals that did fly'.
Do these people actually think that flightless birds were lined up there, learning how they could fly? Prize stupidity if you ask me! And what does that say about you, swallowing this guff? I leave it up to you.
"You have to stop thinking about their wings as flightorgans and as stabilizers instead," Schaller said. "Think about whenyou run around a curb — you use your arms, too, a little like the ostrichesdo."
Ostrich wings are stabilisers, says Schaller. Did you get that? No? Well, they have nothing to do with flight, that's for sure. So again I ask you, what are you doing bringing the subject of flightless ostrich stabilisation in a discussion about flight? I know - you haven't anything else to say. Too bad.
...execute rapid zigzagging as a means of escape, and use their wings to maintainbalance during these agile maneuvers," Schaller explained.
Great. So what does that have to do with the evolution of flight?
http://www.livescience.com/6657-ostrich-wings-explain-mystery-flightless-dinosaurs.html
This is why flight in birds is different than in other flying creatures. It uses a unique movement of the shoulder to flap.
If it is unique, then that means that there is no other like it. Therefore it didn't evolve from anything, but was created as is. Agreed?
...half flapping may have evolved into an ability to fly.
Did you see the word MAY there? That means its most improbable, if not foolishly so. Do you really subscribe to this nonsense?
...Even before
their wings develop enough to fly, some living birds use them to improve traction and gain speed. Dial studied birds, like partridges, capable of only limited flight. Energetically, "It's a lot cheaper to run than fly," Dial said. So these baby birds, with big feet & powerful legs, use them in combination with
their wings, first to stay balanced and grounded, then to take on steeper and steeper inclines. ..."The
wings help them stick to the ground," said Dial.
The wings only come into play on steep angles because at about a 50 - 60 degree incline the birds start slipping..... "They use
their wings like spoilers on a race car, to give their feet better traction," he said. ..Use of this
wing-assisted running doesn't stop when the birds are old enough to fly....
http://people.eku.edu/ritchisong/554notes2.html
This is ridiculous nonsense. The 'birds' or is it reptiles, HAVE WINGS! Why do they have them, if they can't fly with them?
EVERYTHING is different.
Turns out, it's the same thing, just adapted slightly to a different way of moving.
Slightly? Running and flying are SLIGHTLY different? You really need a refresher course in the biology and aerodynamics of flight in birds.
These hopeful reptiles with feathers CANNOT FLY! GLIDING AND FLYING AND RUNNING are entirely different things. Do go and take an elementary course on the subject of the differences. Then perhaps we can talk sensibly.
To move an arm backward and forward requires different musculature and innervation and anatomy to that required to move a wing up and down especially in the figure-8 movement characteristic of flight. The instinctual requirement is also entirely different.
See above. Same motions.
Barbarian, when a reptile runs, the forelimbs move forward and backwards, like our own. When a bird flies, the wings move vertically up and down. That is a completely different kind of movement. You should know better, and not allow this prejudice to blind you.
It's no use saying that the instincts already existed. They would, as I have pointed out, been selected out when they were of no use as yet.
You see the flight motions in ostriches, which cannot fly. And these are anatomically the same as the shoulders and arms of running dinosaurs.
But that is not flying. Dinosaurs and ostriches can't fly - so please stop parading there irrelevancies. And if ostriches have wings then they cannot be the same as the articulation of a dinosaur's forelimbs.
Have you read the stupid article? I doubt it. Imagine saying that ostriches which cannot fly, could be the precursors of birds which can! Sure, they may stabilise themselves with their rudimentary wings, but as you should know by now, stabilisation and flight are 2 entirely different things.
But it's not stabilization. It's using the wings to control movement and change direction. Didn't you read the article?
Clearly you didn't, because that is exactly what Schaller said the wings did. Here: "You have to stop thinking about their wings as flightorgans
and as stabilizers instead,"
I always suspected that you only lifted large chunks without reading them. Now here's proof positive of that.
Just BTW, have you ever looked at the structure of flight feathers? There is no way those could have evolved from reptilian scales.
I
n fact, we can make feathers develop from scutes (specialized scales found on dinosaurs, bird legs, and crocodiles)
Drs. Hongyan Zou and Lee Niswander...identical to crocodilian scales both in composition and their location on the DNA strand.
...
http://www.skeptive.com/sources/66982/source_urls/235148
I fail to see how this bears on the evolution of feathers from scales. At some time in evolutionary history, do you see any PhD's from China injecting proteins and whatnot into the reptilian ancestors of the birds? I haven't heard of any - but doubtless you can produce a P-A--P---E---RRR THAT SHOWS FOSSILISED CHINESE injecting antibodies into alligators to turn them into birds? Ha ha haaaaahhhh!
Just look at the intricate binding and hear Denton on the point:
Each feather consists of a central shaft carrying a series of barbs (see diagram) which are positioned at right angles to the shaft to form the vane. The barbs which make up the vane are held together by rows of barbules (again look at the diagram).
From the anterior barbules, hooks project downwards and these interlock with ridges on the posterior barbules. Altogether, in the flight feather of a large bird, about a million barbules co-operate to bind the barbs into an impervious vane
.
But the simplest feathers lack all of this. And there are gradual intermediate forms between the simplest filament feather, and highly evolved flight feathers.
Learn about it here:
http://www.birds.cornell.edu/AllAboutBirds/studying/feathers/feathers
As I said, there are about 10 different types of feathers on any given bird. Are you saying that they all evolved from one another? Come, Barbarian, not even you can swallow all that nonsense.
All of this goes to show that feathers did not come from reptile scales, by the wind blowing through them or otherwise. (Did you ever hear such a stupid theory? But that's what they say!)
Comes down to facts. And as you see, the evidence is very persuasive.
Facts? What facts?
Denton, again:
The stiff impervious property of the feather which makes it so beautiflul an adaptation for flight, depends basically on such a highly involved and unique system of co-adapted components that it seem impossible that any transitional feather-like structure could possess even to a slight degree, the crucial properties.
And yet as you just learned, such intermediates exist today.
Where?
Barbara Stahl, in Vertebrate History: Problems in Evolution says, as far as feathers are concerned "How they arose initially. presumably from reptiles scales, defies analysis"
See above. Facts trump anyone's ignorance.
Consider your ignorance trumped.
AND DID YOU KNOW THAT THERE ARE ABOUT 10 DIFFERENT TYPES OF FEATHER ON ANY GIVEN BIRD? How did they all arise since about 8 of them are not necessary for flying?
The transitional forms all have functions. Which explains why Denton's argument falls apart. Each could evolve to it's function, so that the last step (asymmetrical flight feathers) would be a very small change from the symmetrical pennate feather.
Ha hah haaahhh! And that's PINNATE, spelt with an I, not an E.
And so should you.
So where did the information come from?
Barbarian observes:
As you see, already there.
As shown above, this is total nonsense.
No, they had been selected out a long. long time ago before flight arose, and because of that, flight COULD NOT HAVE ARISEN.
As you see, that's not the case.
You've just begged the question again.
Did you know that the article refers to a dinosaur the size of an elephant? No? Did you think it could fly? Ha ha haaaaah!
It simply had the avian respiratory system. So it didn't have to evolve in birds. It was already there.
Whether it was or not, is highly dubious to me. And if you would care to explain how an elephant-sized dinosaur begot a sparrow sized bird, I'd like to hear.
http://discovermagazine.com/2003/feb.../#.UVQv7Te1va4
Feduccia there says birds evolved from reptiles. Are you now admitting the fact?
No, merely pointing out that there are grounds for disagreement. Wouldn't you agree?
