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SCI/TECH: Therapod Dinosaurs Did Not Evolve Into Birds

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posted on Oct, 12 2005 @ 09:35 AM
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The generally accepted theory that dinosaurs are the ancestors of modern birds is being challenged. New research published Monday in the Journal of Morphology suggests that what was thought to be "protofeathers" are more likely to be skin-related tissues, according to Dr. Alan Feduccia of the University of North Carolina at Chapel Hill. While these scientists agree that dinosaurs and modern birds share a common reptile ancestor, the theory that dinosaurs are the ancestors of the modern birds is flawed or "..full of holes.."
 



www.brightsurf.com
The researchers also examined evidence from five independent, agreeing studies involving structural and genetic analyses related to the ”tridactyl,“ or three-fingered, hand, which is composed of digits 1, 2 and 3 in dinosaurs, Feduccia said. That is the most critical characteristic linking birds to dinosaurs. They found that embryos of developing birds differed significantly in that bird wings arose from digits 2, 3 and 4, the equivalent of index, middle and ring fingers of humans. To change so radically during evolution would be highly unlikely.

”If birds descended from dinosaurs, we would expect the same 1, 2 and 3 pattern,“ he said.

Current dinosaurian dogma requires that all the intricate adaptations of birds’ wings and feathers for flight evolved in a flightless dinosaur and then somehow became useful for flight only much later, Feduccia said. That is ”close to being non-Darwinian.“

Also, the current feathered dinosaurs theory makes little sense time-wise either because it holds that all stages of feather evolution and bird ancestry occurred some 125 million years ago in the early Cretaceous fossils unearthed in China.

”That’s some 25 million years after the time of Archaeopteryx, which already was a bird in the modern sense,“ he said. Superficially bird-like dinosaurs occurred some 25 million to 80 million years after the earliest known bird, which is 150 million years old.”

Feduccia said the publication and promotion of feathered dinosaurs by the popular press and by prestigious journals and magazines, including National Geographic, Nature and Science, have made it difficult for opposing views to get a proper hearing.

“With the advent of ‘feathered dinosaurs,’ we are truly witnessing the beginnings of the meltdown of the field of paleontology,” he said. “Just as the discovery a four-chambered heart in a dinosaur described in 2000 in an article in Science turned out to be an artifact, feathered dinosaurs too have become part of the fantasia of this field. Much of this is part of the delusional fantasy of the world of dinosaurs, the wishful hope that one can finally study dinosaurs at the backyard bird feeder.

”It is now clear that the origin of birds is a much more complicated question than has been previously thought,\



Please visit the link provided for the complete story.


It appears that this widely accepted theory now has some critics outside of the Creationist community. I am no expert, to say the least, but it seems to me that this team raises some valid questions and presents solid evidence that directly contradicts current theory. It's also important to note that the current theory has no evidence "either structural or biological" and the timeline directly contradicts known evidence of Archaeopteryx, which was already a bird, that predates the fossils with the so called "protofeathers" by some 25-80 million years.


Related News Links:
research.unc.edu
www.science-frontiers.com
66.42.196.197:50002

[edit on 12-10-2005 by Rren]

[edit on 12-10-2005 by Rren]

[edit on 12-10-2005 by Rren]




posted on Oct, 12 2005 @ 09:54 AM
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Yeah, I think these problems have been around for a while though.

It's kinda hard to be older than your grandfather which is the problem with the fossil record of dinos turning into birds...



posted on Oct, 12 2005 @ 10:14 AM
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I dont think Birds came from Dinos, I think dinos where bird like.




posted on Oct, 12 2005 @ 02:07 PM
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Fedduccia's issues are, as presented here, two. One is the issue of whether or not we are looking at protofeathers or, rather, integumentary support structures, like collagen. The other is the identification of the digits in the hand. Right off the bat, there's a problem with these as settling the debate; there are hundreds of characteristics and data/evidences that support the origin of birds from dinosaurs, and specifically'maniraptorian' theropods. The weight of the evidence is for this origin, and the alternative usually proposed by BAND people ('birds are not dinosaurs'), has far, far less support and far more problems than dinosaurs.

Another problem, at least from the news article, seems to be that they are simply ignoring current research on these issues. The homology of bird and dinosaur digits has been addressed in a few papers, and they even absurdly go so far as to state that the 'dino-fuzz' hasn't been described structurally, which is simply false. The simplest dinofuzz is, well, simple, but even it has been described in sufficient detail to distinguish it from collagen.
Here is the abstract to the paper.

On digits:
A solution to the problem of the homology of the digits in the avian hand This seems to be completely ignored by feduccia, as is, so far as I know but I may be wrong, a reply to feduccia's original paper where he insisted that the digital identity issue was fatal to the BAD (birds are dinosaurs) Hypothesis.

Also, its simply rock-headed of Feduccia or anyone else to ask "Do Feathered Dinosaurs Exist", they simply and clearly do. While one can make a case that the simplest proto-feathers might be collagen (albeit a poor and ultimately unconvicning case), other dinosaur specimins clearly and simply show complex feathers, not anything that can be mistaken for collagen.

The abstract doesn't really say what specimins they've looked at, short of

We describe integumental structures, very similar to protofeathers, preserved within the rib area of a Psittacosaurus specimen from Nanjing, China, an ornithopod dinosaur unconnected with the ancestry of birds

Here is the abstract for the Psittacosaur integument paper, I don't know why they are looking at the ribs, considering that the integumentary structures that everyone is concerned about are on the tail, and they do not resemble collagen fibers.

Also, as far as birds being too young to have come from dinosaurs, the dinosaur hypothesis is still far better than the 'arboreal archosaur' hypothesis (which posits that birds descended from lizard like animals long before dinosaurs were around). And, tantalizingly, there are reports of bird tracks from the triassic.


Here are some interesting related web pages:
Feathers, scutes and the origin of birds
The Evolution of Feathers from Dinosaur Hair (and this is before the most recent discoveries)
Feathers, filaments and theropod dinosaurs
Branched integumental structures in Sinornithosaurus and the origin of feathers

[url=http://www.nature.com/nature/journal/v420/n6913/abs/nature01196.html] The Morphogenesis of Feathers


Here is an earlier paper from Soliar
Evolution of birds: ichthyosaur integumental fibers conform to dromaeosaur protofeathers
His arguements were widely rejected two years ago, they don't appear to have changed any. Indeed, Soliar and Feduccia are largely living in the past, repeating arguments that have been continuously rejected in favour of better theories.Feduccia has almost gone border-line non-scientific, rejecting anything that supports the evolution of birds from dinosaurs without reason.

Here are some other related pdfs
The Theropod Ancestry of Birds (the rahonavis paper)

(actually I was going to include more but the above service is very spotty and is out now).



posted on Oct, 12 2005 @ 02:34 PM
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Don't beat around the bush, what do you really think about Feduccia's hypothesis.


I did realize that this B.A.N.D. group was in the minority but i didn't realize how hated they were by the B.A.D. guys (no pun intended). Why is this idea so disagreeable? It is still strict evolutionism is it not(just a different 'path')? I have heard the creationist arguments before but didn't realize that there was support from secular science, are you saying that there is not? Outside of a couple guys of the "verge of pseudoscience".

Thanks for all (
) the links, i have them in my favs. now and will look through them when i have more time.

(edit) it's realize not realise...dummy


[edit on 12-10-2005 by Rren]



posted on Oct, 12 2005 @ 08:32 PM
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Feduccia's arguments were good, a little more than a decade ago. There wasn't anything like teh fossil evidence that there is now regarding feathered dinosaurs and the origins of birds. Lots of people, like Larry Martin and others, also agreed with feduccia's basic idea; that birds evolved from an arboreal archosaur. One of the best lines of reasoning was that dinosaurs simply weren't tree dwellers, the 'ground up' hypothesis had, and still has, lots of problems. I think feduccia was looking to these things called 'drepanosaurs' as a very primitive bird ancestor -or- something that at least showed some bird like adaptations and also shows that the group was highly adapted to tree living.


and when longisquama was found, it seemed to support the 'arboreal archosaurs develop flight by gliding' theory.


I beleive that the head and other skeletal features were considered to be nicely approaching avians, but obviously the big issue there are those incredible integumentary structures.

But then the evidence really started tilting the other way. Cladistics really was showing that birds are a group that come out of dinosaurs, cladistics being a 'new' (actually it was espoused by a guy named Hennig in germany in the 60's i think, but, being that his books were in german, it took a long time to get into the US and into paleontology)and powerful way of analyzing characteristics and determining relationships.




Basically what these sorts of studies confirmed was that you'd need some really unreasonable and unlikely changes to occur to derive birds from these and other arboreal dinosaurs and that the changes that would have to occur in small theropod dinosaurs would be reasonable and likely, given the distribution of characteristics in the specimins. Even if you posited that there were lots of unknown forms, you still have a more 'logical' theory with the small theropod theory. A problem with this was that the ground up hypothesis for the origin of flight, with running dinosaurs becoming birds, just wasn't looking reasonable, and it was extremely difficult to see how feathers could arise in small running dinosaurs as an adaptation; what purpose could they serve, at least in arboreal archosaurs any 'proto-feather' will help gliding, or even slow a fall.
So the focus was on how to explain the origin of feathers and 'the flight stroke' with small running dinosaurs. The recently deceased John Ostrom,

a man who had managed to find a new specimin of archaeopteryx languishing in storage in a european musuem, theorized that feathers could work sort of like a 'net' to surround and scoop in flying insects that these theropods would eat. Others noted that the grasping arms of deinonychosaurs (discovered by John Ostrom in fact) could make a wing-beat like motion when reaching for larger prey. Others thought that wings would give a little boost when chasing prey, or aid in jumping after flying insects and that this lead to flight.
But I think that most of these ideas were simply shown to be non-feasable. If you are running, no proto-wing is going to help you move faster, and if anything the moment you leave the ground you're going to have a huge drop in speed, and the energetics of flapping flight vs simply running faster after insects was poor too.
So there was this one set of information, the cladistic information (the phylogenies, the relations) that was saying, they came from theropods. But the other data seemed to say that it simply couldn't work.
Feduccia also noted that things like archaeopteryx, considered at this time a non-dinosaur and a 'basal bird', had adaptations for perching and tree climbing, and nothing of the sort was seen in small dinosaurs, whereas other archosaurs had such adapatations.
Then the case was simply blown wide open with the rapid and extraordinary discoveries of what can only be described as feathered dinosaurs in china, with everything from very primitive 'shaft' like protofeathers, to increasingly complex symmetric feathers (iow non-flight), and even finally asymmetric flight feathers. This simply showed that birds had evolved from dinosaurs. Whats more, they had adaptations for living in trees, so now we have feathered arboreal small theropod dinosaurs. And, as a sort of scientific icing on the cake, Plum's research (in the post above) showed that modern bird feathers can be progressively 'primitivised' (or at least mutated) into simpler and simpler stages, and these feather evolutionary stages correspond very well to what we actually see in the proto-feathered-to-fully-feathered specimins, even in their phylogenetic order.

This has lead to some BAND people ultimately rejecting (or at least not stumping as much for) the BAND idea, like (I think) Larry Martin. Others, actually really mostly Feduccia, for whatever reason, have adamantly clung to the arboreal archosaur idea, despite the more powerful logic of cladistics, and despite the incredible fossil evidence. Feduccia's ideas reach into the realm of non-science because they reject logic, cladistics is a logical analysis of the data, and their ideas are simply rejected because, if nothing else, of the ludicrously high amounts of 'convergence' that you'd have to have, with small dinosaurs being 'convergent' upon these other 'arboreal archosaur' birds, despite living in different environments even. His ideas fail 'occam's razor', big time, to say the least. His ideas aren't a problem for evolution, except insofar as they are simply more or less unscientific ideas.

There is another faction tho, called ABSuRDists, Anything But Small Running Dinosaurs, who posit all sorts of things. Another line in this research is that of Gregory S Paul, who basically postulated that some of the feathered dinosaurs that we see now aren't actually 'evolving into birds', but rather that flight had evolved in dinosaurs, and that these things are 'secondarily flightless', like emus and the ostrich (and then I'd think that others retained flight and evolved more birdy features, with some populations occasionally loosing flight and becoming ground birds along the way too).

ER, yeah, that was longer than I had intended.

Basically Feduccia is getting looked at cross eyed because his conlusions are simply illogical and have no scientific rationale anymore. This recent paper seems to confirm that. Soliar had published a previous paper on the whole 'they're not feathers, they're collagen' bit, and, like I said, it was pretty baseless, if nothing else microraptor and the like have flight feathers, you can't consider it collagen. So it seems like Feduccia is publishing another paper simply by teaming up with Soliar.

There's lots of other controversies in the situation, like whether or not Wagner is correct about the digit homology, and what I like to call 'Attack of the Chimeras', with the fraudulent Archaeoraptor, the non-fraudulent tho very very controversial Protavis, and even the somewhat controversial and oft ignored Rahonavis.

Oh one last thing, I'll just mention it tho. At the Montana Meeting of the SVP a few years ago, bird researcher Ken Dial demonstrated that very young developmentally birds (young developmental stages imply early phylogentic stages, kinda like Haeckle used to rant about), which can't fly and have poorly developed wings, will, in order to escape predators if they find themselves on the ground, scurry up tall trees, running, and flapping their little wings in such a way that forces are created that help hold them to the tree trunk, allowing them to run straight up a 90 degree incline, even inclines at more than 90 degrees (thats right, approaching being upside down). That would be a tremendous evolutionary advantage to small ground dwelling adult dinosaurs, and might explain how these arboreal dinosaurs first started getting into the trees. The theory is called WAIR theory, wing assisted incline running.

Feduccia's ideas don't really have any effect on evolutionary theory or the creationism issue. Lots of creationists seem to take any disagreement amoung scientists to mean that science is no good, because the scientists can't agree. *shrug*

OK I'll shut up now!



posted on Oct, 12 2005 @ 08:56 PM
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Very, very good Nygdan. Thank you.

Especially the grafix.



posted on Oct, 12 2005 @ 10:09 PM
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Heh... I took a class at UNC Chapel Hill last year that focused almost entirely on the evolution of Theropods into birds


So much for college, I guess.



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