Barbarian observes:
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.
It's observed daily in labs. No one doubts that it happens.
Barbarian suggests:
I've asked you several times to spend a little effort to learn what biology is about. It would be very useful to you.
I find facts very effective, it's why you bailed out of all those threads as the evidence piled up.
Barbarian observes:
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.
Yes, some of them did.
Yes, some of them did.
2 Control and balance do not constitute flight.
They just constitute the structures and behaviors necessary for flight to evolve.
Ostriches are therefore inadmissible as evidence of anything
They merely demonstrate that the structures and behaviors necessary for flight predated flying birds. Which is all evolution needs.
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.
No. Unlike other flying organisms, the feathers constitute the airfoil. The limb itself is not at all aerodynamic. Hence the importance of the preadaptation of feathered bipedal dinosaurs. They already had the structures necessary for flight, and were using them as a bird uses a wing.
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.
New, long-term observations of hand-raised ostriches, model calculations and air-stream experiments have shown that these flightless birds can efficiently channel aerodynamic forces and consistently use their wings during rapid breaking, turning and zigzag manoeuvres.
http://www.sciencedaily.com/releases/2010/06/100630213614.htm
Ostriches have essentially the same shoulder and limb structure as the feathered limbs of dinosaurs. And the wings function as airfoils. It's not surprising that such limbs would become more efficient over time.
Barbarian observes:
Bipedal dinosaurs, as you learned, would use their forelimbs as organs of balance in running But we now know that many of them in the line leading to birds, were also feathered, so that same motion would then be used to control the movement of the animals while running. As you know, ostriches use their rudimentary wings to control their movement while running, in the same way that flying birds control their flight. So the motions were already there, used to a slightly different purpose.
As I said, you need a bit of training in logic.
Rather, you need some evidence for your beliefs, so you aren't reduced to making generic complains about "logic."
We have:
1 bipedal dinosaurs
2 with balancing forelimbs
Feathered forelimbs, capable of performing as airfoils as those of ostriches do.
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."
It's a matter of direct observation. Bipedal vertebrates, with feathered forlimbs, use them as airfoils to balance and change direction.
but what is the connection between flightless ostriches and flying birds?
They use the same structures, with the same motions, to effect movement.
So running and flying are fundamentally different methods of locomotion
As you learned, the use of feathered upper limbs by dinosaurs and ostriches use the same structures and the same movements as those of birds. So flying was merely an adaptation, using structures and behaviors already present.
Yep.
Barbarian suggests:
Well, let's take a look...
... They found the ostriches used wings as sophisticated air-rudders for rapid braking, turning and zigzag maneuvers. Experiments that placed 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.
As you learned, flying was just an adaptation of things already in existence. As dinosaurs became smaller, they were able to first get some lift from their wings, and some became small enough to fly.
..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?
Birds used the same structures, in the same way when they fly. So your question about how did all that evolve, is answered. It's just an adaptation of things already there.
Barbarian observes:
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.
Unique among flying organisms.
Therefore it didn't evolve from anything, but was created as is. Agreed?
As you learned, the evidence shows it is merely an adaptation of things already present in feathered dinosaurs.
This is ridiculous nonsense. The 'birds' or is it reptiles, HAVE WINGS! Why do they have them, if they can't fly with them?
Turns out that they can be used just like bird wings, as airfoils to maneuver.
Except the bones, feathers, motions, forces...
Turns out, it's the same thing, just adapted slightly to a different way of moving.
Slightly? Running and flying are SLIGHTLY different?
Yep. As you learned, the flying motions of a bird are essentially the same as those for a running vertebrate with feathered forelimbs.
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.
Already present. The shoulders of ostriches and feathered bipedal dinosaurs permitted such motions. The transitional dinosaur/bird Archaeopteryx has a slightly more mobile joint, but is is much more like that of dinosaurs than like modern birds. No great restructuring needed for that.
Barbarian, when a reptile runs, the forelimbs move forward and backwards, like our own.
Turns out you're wrong about feathered bipedal dinosaurs. Their shoulder joint is very different than the shoulder of modern reptiles.
When a bird flies, the wings move vertically up and down.
That would produce a net lift of zero. It's more interesting than that. Would you like to learn about it, and see why it fits the movements of cursorial feathered bipeds like dinosaurs and ostriches?
It's no use saying that the instincts already existed.
As you learned they already existed, and were simply adapted to a new use.
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.
It just demonstrates that the flying motions of birds were already present and were merely adapted to a new purpose.
And if ostriches have wings then they cannot be the same as the articulation of a dinosaur's forelimbs.
Bad assumption. Microraptor, for example, had wings, complete with assymetrical flight feathers.
Barbarian chuckles:
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.
Well, let's take a look...
After three years, when the ostriches were full-grown, thescientists video-recorded them as they raced down nearly 1,000-foot (300-meter)stretches outdoors. 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.
http://www.livescience.com/6657-ostrich-wings-explain-mystery-flightless-dinosaurs.html
Surprise.
I always suspected that you only lifted large chunks without reading them.
And now it turns out you did exactly that. The above was directly above the snippet you edited out to make it look as though ostriches don't use wings as airfoils.
Just BTW, have you ever looked at the structure of flight feathers? There is no way those could have evolved from reptilian scales.
As you learned earlier, scales can be induced to form feathers. And we have existing even today, a full range of intermediate feathers from simple filaments to complex flight feathers. It's rather perverse to deny what manifestly exists.
Scales can form feathers:
http://www.skeptive.com/sources/66982/source_urls/235148
Just look at the intricate binding and hear Denton on the point:
(Denton is apparently unaware of all the intermediate forms of feathers)
Poor fellah.
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.
Barbarian chuckles:
And yet as you just learned, such intermediates exist today.
Learn about it here:
A piece of amber formed of tree sap from 100 million years ago has preserved crucial evidence of feather evolution.
Evolution has long predicted the evolution of birds from reptiles, and recent discoveries of feathered dinosaurs has proved that model correct. However, the dinosaurs feathers found to date have been primitive in form, while bird fossils exhibit complex, barbed feathers required for flight.
This new fossil feathers, discovered in France, are intermediate in form between the simple downy feathers of early avian dinosaurs and the complex flight feathers of birds.
http://www.prehistoricplanet.com/news/index.php?id=43
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"
Barbarian observes:
See above. Facts trump anyone's ignorance.
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?
Barbarian observes:
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.
Typo flame. Cool.
So where did the information come from?
Mutation and natural selection. Would you like me to show you how every new mutation produces new information in a population? The math is very straightforward.
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!
Barbarian chuckles:
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.
Doesn't matter. Facts are very resistant to wishes.
And if you would care to explain how an elephant-sized dinosaur begot a sparrow sized bird, I'd like to hear.
There was a continuing trend in many lines of dinosaurs to smaller ones. Would you like to learn about that?
(Async endorses the concept that birds and dinosaurs have a common ancestor)
http://discovermagazine.com/2003/feb.../#.UVQv7Te1va4
Feduccia there says birds evolved from reptiles. Are you now admitting the fact?
Then it's probably a mistake for you to cite his opinion that they did.
At one time, there was a very small chance that Feduccia was right, and birds and dinosaurs evolved from a common thecodont ancestor. But given the fossils found since then, it's too unlikely to get many to accept it.
But of course, either case would be inconsistent with your beliefs.
