[Asyncritus (OP)]

As you may not know, there are about 10,000 species of birds and there are millions of individuals. They are a massively important group of animals.

Now here's the nightmare bit.

Birds are supposed to have evolved from reptiles (har de har!). Everybody knows that, even a 7-year old I heard in a pharmacy telling her mom: 'The dinosaurs became birds, you know mom' she said.

In other words, this:



came from that!!!!




Heh heh!

A trifle unlikely, wouldn't you say?

There's a BIGGGG problem with that: the bird lung.

As you all know, when we (and every other vertebrate) breathe in, the air enters our lungs, gas exchange takes place (ie oxygen is taken up and carbon dioxide and water are given off). We then breathe OUT, and the gases go out the same way it came in.

So to emphasise, when we breathe IN, the air comes INTO the lung. When we breathe OUT, air leaves the lung. With me so far? OK.

The birds ARE EXACTLY THE OPPOSITE OF THAT!

When a bird breathes IN, the air DOES NOT ENTER THE LUNG.  It goes into AIR SACS, which are NOT LUNGS.

When the bird breathes OUT, then the air goes into the lungs!!!!

So there's no way that a bird's lung could have evolved from a reptile which breathes like us.



Theropod dinosaurs breathed using a diaphragm to force air in and out of the lung.

Guess what? Birds DON'T have a diaphragm. Where'd it go, I ask myself.

Over to you, guys!

[neilep]

How could all the bods who say that birds did evolve from dinosaurs miss that ? Surely they considered it...what is their explanation ?

[Don_1]

Again you demonstrate your lack of understanding of evolution. You can no more put all the dinosaurs into one basket than you can the apes.

Peacocks or any other bird you care to mention did not evolve from crocodilians. Crocodiles, alligators and caymen evolved from the early crocodilians. Neither did they evolve from Pteranodon or Pterodactyl.

Birds evolved from Archaeopteryx, a feathered flightless (although possibly gliding) dinosaur, often referred to as the earliest bird, and Sinovenator changii, another possibly feathered dinosaur of the same period (around 130m years ago). Other feathered dinosaurs have also been found which probably also became birds.

Please don't think T Rex, Diplodocous, Stegosaurus only when thinking of dinosaurs. These are the big ones and there were many bigger. But there were far more small dinosaurs than there were giants.

Look at the Tortoise, yes there were the giants, but there were, and still are, the very much smaller Horsefield, Hermann, Marginated etc. Even the Spur Thigh has the giant African species and the very much smaller Mediterranean species.

Many dinosaurs perished in a great extinction. They do not have modern day successors. The crocodlilians and tortoises survived due to there habits. The feathered dinosaurs survived due to there feathers. Other small dinosaurs evolved into these:



Birds came from this:
Fossil of Archeopterix


Impression of Archeopterix based on fossils.

As you can see the reptilian scales have aleady evolved into feathers on this 130m year old dinosaur.

[BenV]

Oh dear, how preconceptions can get in the way of doing a little basic research.  Within less than a minute of doing a google search for Bird Lung Evolution, I found a paper in nature showing the evidence for the existence of a very similar breathing apparatus in dinosaurs.

http://www.nature.com/nature/journal/v436/n7048/abs/nature03716.html

And this one from Integrative and Comparative Biology, looking at gene regulation of lung evolution:

http://icb.oxfordjournals.org/cgi/content/abstract/icm069v1

Furthermore, bird lungs are more efficient than mammalian lungs - so if mammals were designed instead of evolved, why wouldn't they have the more efficient system?  The answer is this:  They evolved, and were not designed.

Edit:

Reptiles breathe using a diaphragm to force air in and out of the lung.

Guess what? Birds DON'T have a diaphragm. Where'd it go, I ask myself.

Most reptiles, with the exception of crocodilians, don't have a diaphragm.  They ventilate by moving the ribs. So where'd it go? It was never there.

[Don_1]

Reptiles breathe using a diaphragm to force air in and out of the lung.

Not true.

The Tortoise is a reptile, but it does not have a diaphragm.

From Reptiles.net

One of the biggest problems with growing an immovable and impenetrable shell is that breathing can be a big problem. Since their is no movable flesh to allow for expansion of the lungs nor a diaphragm to expand them. So chelonians had to find a new way of handling this problem.
When this was first being considered, researchers thought that, like amphibians, chelonians achieved respiration by gular pumping. That is they thought that the constant throat pumping movements seen in these animals was used to force air into the lungs. This has turned out to be false and gular pumping in chelonians is now known to be of olfactory (smelling) signifigance.

So how do they breathe?

Breathing is accomplished by the creation of a negative pressure differential (i.e. the air outside has a higher pressure than the air inside, so through the process of diffusion, the air will enter this "negative air space" and fill the lungs). ........It has already been established that they don't use gular pumping for the purpose of inhalation, they don't have diaphragms and the ribs now form a part of the shell, so intercostal breathing is out as well. Chelonians had to find another way.

This negative pressure differential (NPD) is partly achieved via the shell. In tortoises breathing is accomplished by the use of the rigid shell and the toroise's musculature. The muscles used for breathing expand into the limb pockets at the borders of the shell and serve to modify the internal pressure within a chelonian's body. So when the tortoise moves it is expelling air in one movement and taking in air with another. This would also explain why resting turtle's and tortoise's forelimbs move in and out.

So you see evolution deals with different problems in different species in different ways according to that particular species needs.

[Don_1]

Asyncritus, I assume you are a Christian, Jew or Muslim and believe in God, the Creation & the Bible.

I was born into Christianity and taught to believe in God and the Bible. But from a very early age (about 10 yrs) I began to question these teachings. Paleontology and archeology seemed to have something concrete I could look at, feel and understand. I became an agnostic. Over the subsequent years I have turned to atheism, because I can see no logic in the Bible's explanation of creation and, like so many people, even believers, I question how the great creator would allow one of his creations to begin the systematic destruction of all the others. Why does he allow the suffering of the innocent? Why does he not punish the wrong doers? There are a thousand questions I could ask, and get no answer, save those of theologians, who can show me no evidence.

Is Christianity right? Is Islam right? Is Judaism right? Are Jews the chosen ones? Why did God allow the Indian ocean tsunami? Did He in fact create it? Why?

For me there are no answers to such questions from religion.

The answers come from nature and from man himself, or the question remains unanswered.

I am comfortable with my view of life, the universe and everything else. I reached MY OWN decisions on such matters. Nobody encouraged or brainwashed me.

I am happy that you are comfortable with your views. I respect your views and would not seek to force you into abandoning your faith. So please stop questioning mine.

We will never agree, and must be contented with that fact.

[Asyncritus (OP)]

Don

I presume you have some interest in science, which is why you're here.

I am presenting a scientific fact, as opposed to Ben V and the others who are presenting guesses galore.

We, as reasonable human beings, with scientific inclinations of one sort or another, have a fact before us on the one hand, and some claims on the other.

We are attempting to explain how black could be white, how a bird lung which has air entering the lung on EXHALATION, could possibly have evolved from a reptile whose air enters on INHALATION. And how a bird which has no diaphragm could have evolved from a reptile with a diaphragm. (The theropod ancestors of the birds had diaphragms as Ruben said very clearly).

Where did the diaphragm go, and how could ANY reptile survive with a great hole in the bottom of the lung just emerged?

We're discussing science, not theology.

[Asyncritus (OP)]

Ben your points have no validity.

The theropods (alleged bird ancestors) had a diaphragm:

"The theropod dinosaurs seem to have had a diaphragm (like crocodiles do), but birds do not have diaphragms, and there is no evidence that they ever did have them. Rather, birds have a unique respiratory system. Ruben et al. (1997) claim that the differences in the theropod and bird respiratory systems "pose fundamental problems" for a direct relationship."http://www.mandley.com/advdemo/mod10/adv10300.htm

"The evidence that the theropod dinosaurs possessed crocodile-like lungs is reinforced by skeletal analysis suggestive of a liver-diaphragm lung ventilation mechanism in these dinosaurs. Crocodiles have a non-muscular diaphragm, powered by muscles which attach to the liver and the pubic bones of the hip. It pulls the large liver backwards to inflate the lungs, and is associated with a distinctive hip structure.

"The theropod dinosaurs, which were the supposed ancestors of the birds, included such prominent species as the Tyrannosaurus rex and Velociraptor," Jones said. "In them we see a marked similarity between the hip structure of theropod dinosaurs and crocodiles."

"This, along with the discovery of new evidence of a non-muscular diaphragm in two specimens of Sinosauropteryx, the recently discovered theropod from China, leads to the conclusion that theropod dinosaurs, like crocodilians, used a liver-diaphragm mechanism to ventilate their lungs.

The skeletal structure of the earliest birds indicates they also possessed a simple reptile-like lung, consistent with their being cold-blooded. But unlike the theropod dinosaurs, they lacked a diaphragm mechanism with which to fill their lungs" http://oregonstate.edu/dept/ncs/newsarch/1997/November97/nodinobird.htm

You really should check your references a bit more thoroughly, Ben.

[Asyncritus (OP)]

How could all the bods who say that birds did evolve from dinosaurs miss that ? Surely they considered it...what is their explanation ?

They didn't miss it, but they can't explain it. Have a look on google and you'll see the guesses.

Tough luck, guys.

[neilep]

LOL...even if we agreed with you you'd probably disagree !

[Asyncritus (OP)]

Furthermore, bird lungs are more efficient than mammalian lungs - so if mammals were designed instead of evolved, why wouldn't they have the more efficient system?  The answer is this:  They evolved, and were not designed.

The reason for the difference is very obvious. Birds use up a huge amount of energy in flight. That's why they need the extra efficiency.

Most reptiles, with the exception of crocodilians, don't have a diaphragm.  They ventilate by moving the ribs. So where'd it go? It was never there.

See above.

[Don_1]

The Anapsidas (approx 300m yrs ago) pumped air by buccal breathing. Their only surviving modern day form, the Testudines (Tortoise and turtle) evolved a new way of pumping air into the lungs, as I have shown above.

As I have said you cannot accept that evolution means change, adapting, improving.

OK, you say you are not talking theology, so you tell me in a word, where did birds come from if not through evolution?

[BenV]

Actually, the source you quoted there is nearly a decade older than the papers I referenced.  Science moves on as it finds more evidence.  You should really check your references better.

Furthermore, bird lungs are more efficient than mammalian lungs - so if mammals were designed instead of evolved, why wouldn't they have the more efficient system?  The answer is this:  They evolved, and were not designed.

The reason for the difference is very obvious. Birds use up a huge amount of energy in flight. That's why they need the extra efficiency.

So your designer intentionally built in inefficiencies? What nonsense.

[Asyncritus (OP)]

Easy. God made them.

[Asyncritus (OP)]

Actually, the source you quoted there is nearly a decade older than the papers I referenced.  Science moves on as it finds more evidence.  You should really check your references better.

Furthermore, bird lungs are more efficient than mammalian lungs - so if mammals were designed instead of evolved, why wouldn't they have the more efficient system?  The answer is this:  They evolved, and were not designed.

The reason for the difference is very obvious. Birds use up a huge amount of energy in flight. That's why they need the extra efficiency.

So your designer intentionally built in inefficiencies? What nonsense.

The birds lungs haven't changed since they were first described, yonks ago. So don't tell me about that.

And I don't imagine we would do very well with bird lungs - our life spans would be reduced enormously.

What I'm asking for, is: How did a bellows lung ever produce a unidirectional arrangement.

More air sacs in theropod bones don't make a unidirectional system, just as more cul-de-sacs don't make a one way ring road.

And, of course, if it did, we have to account for the how and why of it's doing so:

Reptile A (bellows) -----X-----> Reptile B (unidirectional).

What happened in the middle at X?

[Bored chemist]

Easy. God made them.

Badly.

Not really worth getting up on a Sunday morning to worship Him then.
BTW, who made God?

[BenV]

Asyncritus, is there any evidence we could present that would satisfy you?  You're clearly able to look things up yourself, so why bother us about it?

If, as I suspect, there is no evidence that anyone could present that would get you out of the fantasy that your imaginary friend created everything, then your posting on this forum is either i. a crusade, or ii. trolling.  Neither of these are acceptable on this forum.

If you are unwilling to accept the evidence, then why not discuss this on a creationist forum with like minded individuals?  You must bear in mind that although you may think evolution does not occur, many people on this forum don't believe in the existence of your god.  This means that your suggestion of how species arise is laughable (to me at least), and you may as well be saying that all life on earth was forged by faeries in a pit in the magic forest.

Evolution has been well studied, we've seen it in action in labs and in the wild and we understand how it works.  As with all science, there are gaps to be filled, but these gaps don't in any way suggest that evolution is incorrect.

Please tell us what evidence will sway your thinking, or go elsewhere.

[Asyncritus (OP)]

Asyncritus, is there any evidence we could present that would satisfy you?  You're clearly able to look things up yourself, so why bother us about it?

This is a science forum.
Scientists disagree, sometime fiercely.
Is that a reason to close down discussion, saying go publish elsewhere? What would you think if Nature or Scientific American acted like that?

But they effectively have - no creationist or ID person is published in their pages, at least, not being able to say what they really believe? Are you going the same way?

Is this forum a mutual backslapping society, or is it a place when someone comes along who disagrees vigorously and in evidenced fashion, we can all look at pros and cons?

Do you want your readership to never know about the objections to evolution, so that when they do encounter someone who knows a bit about the subject, they get kicked in the teeth?

Science is supposed to be a free for all, where as long as evidence can be presented, the presenter is listened to, rather than shouted down. The church did a lot of this in the Middle Ages - and we all, myself included,think that their behaviour was appalling.

So are you going to follow in their footsteps, or act in a more enlightened manner?

What evidence will sway my thinking?

1 Some verifiable evidence of the way in which the great instincts and complexities I have presented could have evolved.

2 Some evidence that mutations can possibly account for the vast number of species today

3 Some serious evidence that life just happened in the pre-biotic soup

4 Some really undisputed transitionals between the major phyla, like the angiosperms, fish, reptiles, mammals.

5 Some serious accounting for the evidence of design in organs like the human eye, the rock lobster's eye, the mammalian ear.

6 Some explanations (evidenced) of the way a four chambered heart could possily have evolved from the one-chambered heart of the lower animals.

[BenV]

no creationist or ID person is published in their pages, at least, not being able to say what they really believe? Are you going the same way?

Just as no person claiming that life was created by faeries has been published.  Your ideas are based on a flawed assumption, and so journals wouldn't publish them.

Is this forum a mutual backslapping society, or is it a place when someone comes along who disagrees vigorously and in evidenced fashion, we can all look at pros and cons?

The issue is that you are unwilling to engage in discussion, you merely tell us we are wrong and your imaginary friend did it.  You ignore the evidence we present, and although some of your objections are evinced, your alternative is based on fantasy.

1 Some verifiable evidence of the way in which the great instincts and complexities I have presented could have evolved.

2 Some evidence that mutations can possibly account for the vast number of species today

3 Some serious evidence that life just happened in the pre-biotic soup

4 Some really undisputed transitionals between the major phyla, like the angiosperms, fish, reptiles, mammals.

5 Some serious accounting for the evidence of design in organs like the human eye, the rock lobster's eye, the mammalian ear.

6 Some explanations (evidenced) of the way a four chambered heart could possily have evolved from the one-chambered heart of the lower animals.

The vast majority of evidence for evolution is available online, yet you expect us to collect it for you and serve it on a plate for you to ignore.  You keep saying 'serious evidence' or 'undisputed evidence' but you ignore or dispute all the evidence you are presented with.  You are now claiming that there is 'evidence of design', so please supply it.

I'm too busy to read and collate all of the evidence you seem to require, and I know that if I were to supply it you would again shift the goal posts and demand more.

So lets try a different tac - There is plenty of evidence for evolution and the mechanisms are well understood, even if specific examples need further elucidation.  Please can you supply some evidence that:
i. God exists, and some evidence of what created him
ii. God created everything (this will involve you demonstrating something that can not have possibly evolved - it will need to be non-genetically controlled, counter to the reproductive success of the individual and species)

You cannot hold god and evolution up to different standards of evidence.

[Evie]

Hmmm...not sure why, but some of this reminds me of a good quote...

"He can compress the most words into the smallest idea of any man I know." - Abraham Lincoln