Archaeopteryx and Dino-Bird Evolution

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If it were alive today, it would be classified as a bird.

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Archaeopteryx is a bird only because scientists have decided that they will make the definition of Aves broad enough to include Archaeopteryx. The boundaries of the classifications are artificial, and in this case they are arbitrarily placed so as to include Archaeopteryx.

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"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

Oops. I just wiped out your flag to metatron.Try putting a message in the topic promotion thread asking a moderator to put a note into metatron's post.

Heh. I have seen that classification scheme, too, so perhaps I shouldn't have been so quick with my fancy scientific terminology.This does sort of support our points, though (notice me making lemonade?): if one arbitrarily only considers Aves to be birds, then Archaeopteryx is then not a bird. If, on the other hand, all the members of Avilae have the features that we naturally want to associate with birds, then Archaeopteryx can be considered a bird.What is and is not a bird is rather arbitrary (like most definitions), and unfortunately for Springer's point, how one classifies Archaeopteryx is less important than the fact that it's classification brings up these issues, just as we would expect from a bird/theropod transitional.(By the way, I think it is a matter of contention among those who like to be involved in contentions whether Aves should be the crown group of modern birds or the crown group of modern birds and Archie. Since I'm not a biologist or palaeontologist, I don't have a dog in that race.)

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"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

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technically, all birds are theropod dinosaurs -- but technically we're also reptiles, right?

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I was writing from the stand point of traditional taxonomy, which recognizes paraphyletic groupings. Not all biologists, or even all systemists, have yet adopted an entirely phylogenic approach to classification, so I will switch from one to the other as it is convenient for me. Bad habit on my part: it does open the possibility of equivocation.As far as whether mammals are descended from reptiles (or are reptiles or whatever) -- as I mentioned, I don't like that. I've read that the last common ancestor of modern reptiles and mammals was early enough that it still had many amphibian characteristics. I would assume, then, that as the line that led to reptiles further evolved their distinctive reptilian features, the synapsids would have evolved in a different direction (unless there was some sort of convergent evolution). Of course, on can define (and people did and probably still do) define reptile in such a way to include synapsids and therapsids. Me, I prefer to think of reptiles and mammals as closely related but independent lineages of the early tetrapod line. But, not being a biologist, there's no reason for anyone else to accept my musings.At any rate, even if one does accept that synapsids were reptiles, then whether mammals are reptiles would depend on whether reptile has a place in a completely phylogenic classification -- I don't think it does, I think that Tetrapoda (which, like Aves, has caused some contention as to what it should include) is used instead. I have the impression that reptile is more a taxon in the older scheme that considers it a paraphyletic group. But I could be wrong here, or it could easily change as the schemes change.

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"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

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There is not one intermediary, transitional form that has ever been presented with any semblance of validity.

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Actually, there are hundreds, even thousands, of known intermediaries. Kathleen Hunt has written a pretty good description of a few of the important ones. And her essay is now out of date -- it doesn't list tiktallik for example.-

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For starters, Archaeopteryx was the size of a pigeon -a vast difference from the megalithic-sized beasts they claim that it spawned.

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Huh? What are these "megalithic-sized" animals, and why couldn't Archaeopteryx have "spawned" them?-

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Furthermore, avian are endothermic (warm-blooded) and reptiles are exothermic (cold-blooded). Avian have temperatures upwards of 105 degrees, whereas, reptiles as low as 40 to 60 degrees. Reptiles have a three-chambered heart, whereas Avian have a four-chambered heart. Avian have hollow bones and saurian have solid bones. The lungs, heart, nervous system, digestive tract are completely different from birds and reptiles.

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Why couldn't these Avian features have developed from the earlier reptilian features?-

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Please tell me, though, how this creature developed wings, a beak, feathers, a completely different heart, lungs, digestive tract, etc, in one felled swoop.

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It didn't happen in one fell swoop. It happened gradually, over a long period of time.-

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What unseen event precipitated the changes to occur, far in advance of any conceivable relevance to its survival?

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That is an interesting question; what were the environmental pressures which led the the evolution of these particular features? People are still working on this. However, we do have evidence that it did happen, and this question doesn't invalidate the evidence.-

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How is it that this creature was able to survive natural selection with stump-like appendages as its ancestors were changing from reptile to bird?

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Probably the early wings were not stump-like appendages. Why do you think they were?-

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The fact is, Archaeopteryx was not a bird-like dinosaur....

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Actually, it is. It has more dinosaurian characteristics than bird characteristics. This essay describes some of these. Why do you think that Archaeopteryx was just a "perching bird"?

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)

Hello, nemesis.

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Given the large changes that were required of reptiles in order to change into birds...

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And what, exactly, is the problem with these "large changes"?-

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...coupled with the fact that there is no prevailing evidence of such....

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There is plenty of evidence that life in general has evolved from a very few, single celled forms over three and a half billion years. There is a lot of evidence that birds, mammals, and reptiles all share a common ancestor. Further, the evidence indicates that birds evolved from theropod dinosaurs. I am afraid there is a lack of evidence only because you won't look at it.

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)

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Revision? Absolutely! Science is always open to revisions (or revolutions).

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Unlike certain religious dogmas that I can think of, which are not open to revision no matter how contrary the evidence is, or how illogical they become.

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)

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That is macroevolution, and it has never, ever been observed, either walking the earth today or in the strata layer.

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Actually, it is observed in the hierarchical classification of species, the confirmation of the standard classification in molecular studies, in the existence of many transitional species in the fossil record, in the existence of vestigial organs, in the existence of atavisms and retroviral insertions, and on and on.As I have stated before, there is strong evidence for common descent. That you refuse to acknowledge the evidence is not going to make it go away.

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)

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And there is a bald-faced assertion that you cannot support with anything other than further bald-faced assertions.

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Yes, "nemesis_juggernaught" is turning out to be not much of a nemesis, and certainly no juggernaught!

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)

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First of all, Darwin thought of many things that simply aren't true, such as, diet, environment, and exercise being responsible for evolutionary change because evolution requires evolutionary advances to be inherited.

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Actually, all Darwin required was that (1) physical characteristics are inherited, (2) that new characteristics can arise, and (3) that some new characteristics will give to the individuals that possess them an advantage in surviving and leaving behind offspring. All of these things have been observed. The exact mechanisms for the inheritence are unimportant.This is getting far from the topic of archaeopteryx; maybe I will start a new thread concerning evolution in general and invite you to participate.-

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As well, there is no vestige that doesn't serve some sort of function.

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The human appendix serves no known function. At any rate it is not necessary that there be no function, just that the organ no longer serves its original function. (Jaws, by the way, are vestigial gills.)This, too, is getting far off the topic of archaeopteryx. You are welcome to start a new thread on vestigial organs if you wish.-

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Alright, viruses that mutate shouldn't shock in the least.

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This is off the topic of archaeopteryx, as well as irrelevant to what I said in my previous post.

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)

Yo, nemesis,you state:

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First of all, Darwin thought of many things that simply aren't true, such as, diet, environment, and exercise being responsible for evolutionary change because evolution requires evolutionary advances to be inherited.

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I replied to it in a subsequent post, but it would be off topic to continue in that vein. So I invite you to new thread to discuss the generalities of the theory of evolution.

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"Religion is the best business to be in. It's the only one where the customers blame themselves for product failure."
-- Ellis Weiner (quoted on the NAiG message board)