B.A.R.B: Birds Are Really…..Birds!
| June 26, 2009 | Posted by Robert Deyes under Intelligent Design |
The summer of 2000 promised to be very exciting for ornithologists and paleontologists alike as they flew into Beijing for the fifth quadrennial meeting of the Society of Avian Paleontology and Evolution (Ref 1). The setting was most appropriate given the richness of fossils that have been unearthed in Chinese soil. The central theme of the meeting lay in trying to resolve the question of whether birds had really evolved from dinosaurs (Ref 1). However, rather than a harmonious discussion with the constructive disagreement that one might expect from any scientific ‘get-together’ aimed at resolving discrepancies in data, the meeting did nothing but expose an underlying discord (Ref 1).
While some scientists such as Berkeley’s John Hutchinson and Yale ornithologist Richard Prum were frustrated over issues that they considered long resolved, others were much more skeptical about the certainty of the facts. Storrs Olson, head of ornithology at the National Museum of Natural History, weighed in by accusing Prum of engaging in “ideological mumbo-jumbo” when Prum claimed that feathers had the same evolutionary origin as “hair like integuments found on dinosaur fossils” (Ref 1). So strong was Olson’s feeling against the evolutionary link drawn between birds and dinosaurs that throughout the meeting he and others wore badges stating their case: “BIRDS ARE NOT DINOSAURS” (or B.A.N.D for short; Ref 1). University Of North Carolina paleontologist Alan Feduccia, well known for his discussions on temporal discrepancies between bird and dinosaur fossils, was similarly uncertain about the dinosaur-bird link. Feduccia made his uncertainty public to the sound of accusations claiming a creationist undertone (Ref 1).
With the latest evidence Olson and his ‘BAND of merry men’ appear to have been vindicated. New data on how birds breathe makes the dinosaur-bird link untenable. According to a recent study, the unique thigh bone and muscle structure in birds’ legs play a key role in preventing lung collapse (Ref 2). For birds, that need about twenty times more oxygen than say reptiles, such structural support is crucial to survival (Ref 2). Theropod dinosaurs from which birds are thought to have descended, did not sport such a fixed thigh bone structure and are therefore not viable candidates for a hypothetical bird ancestor (Ref 2).
Of course the impasse over how birds evolved extends well beyond thigh bones and muscles. In fact, the origin of feathers continues to be a formidable stumbling block for ‘evo-philes’. To further understand the difficulty that the feather poses to the assumed evolutionary transition from dinosaurs to birds, consider the feather’s structural foundations. What we know is that the central rachis (or shaft) of the feather branches off into smaller barbs and barbules. The barbules are equipped with tiny hooklets at their ends that interlock with ridges in the posterior barbules to form an impervious, tightly-held vane (Ref 3).
From an aerodynamic standpoint, the arrangement of the feathers in the overall shape of the wing makes for an aerofoil that displays minimal levels of turbulence (Ref 3). The ability to change the geometry and shape of such an aerofoil makes it ideally suited for the various tasks that the bird has to perform such as landing, soaring and flapping. From a molecular and cellular perspective, the story is no less fascinating. The feather follicle, from which the central rachis projects, contains specific zones of epithelial cells specialized in the formation of each of the components of the feather (Ref 4). The molecular mechanisms by which such cell specialization is achieved have also been elucidated in recent years (Ref 4). Through concentration gradients and a highly-regulated activation of specific genes, the morphogenesis and development of a feather is a very tightly-controlled affair (Ref 4).
With such a realization, we begin to get a sense of why it was that twenty three years ago biologist Michael Denton so emphatically decried the step-by-step, unguided evolutionary origin of wings (Ref 3). As Oregon State University Professor John Ruben humorously quipped, “a velociraptor did not just sprout feathers and fly off into the sunset” (Ref 2). The wing- the perfect aerofoil- must meet rigorous criteria before it can provide the necessary lift (Ref 4). No slight fraying of dinosaur scales would have done the job.
Seemingly oblivious of these intractable challenges, some scientists have gone all out to prop up their evolutionary meanderings by focusing on the three-fingered limbs of theropod dinosaurs and modern day birds (Refs 5,6). Paleontologists Xing Xu and James Clark for example recently published on two specimens of a 156 million-old, toothless-beaked, herbivorous theropod called Limusaurus inextricabilis that, they maintain, is a Darwinian-style ‘missing link’ (Refs 5,6).
One factor that has long been a source of consternation is that the finger digits of theropods and birds do not appear to match. While theropods seemingly carried digits 1,2 and 3 of the pentadactyl arrangement, birds display what scientists believe to be digits 2,3 and 4 (Refs 5,6). Xu and Clark have ruffled feathers by claiming that theropod digits have historically been misidentified. Based on their study of L. inextricabilis, they contend that just like in birds early theropods would have had digits 2,3 and 4 (Refs 5,6).
Such a conclusion is not without its critics. In fact prominent Yale evolutionary geneticist Gunter Wagner has questioned the numbering assignments of bird digits adding that bird wings might be based on digits 1,2 and 3 after all (Ref 5). Wagner cites fundamental aspects of embryonic development in support of his case. University of California paleontologist Kevin Padian has similarly suggested that the digit morphology of L. inextricabilis might represent nothing more than an “oddly reduced hand”, commensurate with its herbivorous lifestyle (Ref 5).
Today, nine years after the Beijing meeting, Olson would seemingly be justified in wearing his famous badge. For him and others, the ‘B.A.N.D’ does indeed play on. To be sure, contemporary evidence shows birds to be a distinct phyletic group not easily integrated into a man made evolutionary scheme. While evolutionists point proudly to the apparent anatomical similarities between birds and dinosaurs, they themselves admit to the pressing need to resolve crucial questions about the origin of flight, the evolution of feathers and the conversion to endothermy (Ref 7).
These are not side questions designed to obfuscate discussions, but rather questions that are central to the matter at hand. In light of such facts, perhaps a more radical message needs to be conveyed that echoes the beat of a different mantra: BIRDS ARE REALLY BIRDS (or B.A.R.B for short). It is perhaps time to re-examine our most treasured notions of bird evolution.
Literature Cited
1. Rex Dalton (2000), Feathers fly in Beijing, Nature, Volume 405, p.992
2. See ‘Discovery raises new doubts about dinosaur-bird-links’, http://www.eurekalert.org/pub_releases/2009-06/osu-drn060809.php
3. Michael Denton (1986), Evolution: A Theory in Crisis, Adler and Adler Publishers, Bethesda Maryland, 1st Edition, pp. 202-208
4. Mingke Yu, Ping Wu, Randall B. Widelitz, Cheng-Ming Chuong (2002), The morphogenesis of feathers, Nature, Volume 420, pp.308-312
5. Matt Kaplan (2009), Dinosaur’s digits show how birds got wings, 17 June 2009, Nature, doi:10.1038/news.2009.577
6. Xing Xu, James M. Clark, Jinyou Mo , Jonah Choiniere, Catherine A. Forster, Gregory M. Erickson, David W. E. Hone, Corwin Sullivan, David A. Eberth, Sterling Nesbitt, Qi Zhao, Rene Hernandez, Cheng-kai Jia, Feng-lu Han, Yu Guo (2009), A Jurassic ceratosaur from China helps clarify avian digital homologies, Nature 459, pp.940-944
7. See ‘Are Birds Really Dinosaurs?’, http://www.ucmp.berkeley.edu/diapsids/avians.html
43 Responses to B.A.R.B: Birds Are Really…..Birds!
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Jehu
From my point of view, that’s the easy part. I’m asking you to not only give an example of an evolved wing but an example of a designed wing and explain how you know one is designed and one evolved.
?
I would have thought it was obvious. I don’t believe you can
A) Give me an example of a designed wing
B) Explain why it’s designed in any detail other then saying “it’s designed”.
It’s you who is making the claim that some wings are designed. I’m just asking for an example! And I’m wondering how you came to that determination!
My planned rebuttal is to simply ask “and how do you know that” when you give your example of a designed wing. But I was quite clear in my original request that I wanted a designed and a evolved wing example. You have simply ignored the latter part of my request, choosing to focus (for some reason) only on the “evolved wing examples”.
No, I’m hoping that when you realise you cannot give me the example I’m looking for it might dawn on you that you’ve no evidence to base your opinion on.
Prove me wrong.
1 example of a “designed, not evolved” wing is all it will take. Then I might reassess my position if your argument is strong enougth.
This term “creationist” seems to get broader and broader.
Lord Timothy:
That’s because “creationist” has more and more become just a barbed — and otherwise largely meaningless — smear word used by darwinist advocates to tag those one wishes to dismiss without actually addressing what they have to say on the merits.
The ongoing Answers to judge Jones thread gives sad but ample cases in point. For, instead of dealing with a serious — and ID-foundational — 1984 technical monograph on the merits, Darwinist advocates have taken to tagging the author of the foreword and the authors of the monograph then dismissing them.
Poisoning the atmosphere.
GEM of TKI
Echidna-Levy
Personally, I’m a front-loader. I believe DNA was designed; I’m less sure about bird wings. To be truthful, I don’t know much about bird wings, but if I wanted to find out whether one was designed or not, this is what I’d do.
METHOD A
1. Identify the genes that code for that wing, in terms of its embryological development and its structural components.
2. Identify a plausible antecedent for the wing – i.e. the structure it supposedly evolved from. (How? Look around the animal kingdom – and especially at reptile anatomy, as birds are descended from primitive reptiles.)
3. Identify the genes coding for that structure.
4. Recalling that evolution takes place at the level of the gene, and that “nature does not make leaps,” I’d try to find a stepwise incremental pathway from the genes identified in step 3 to the genes identified in step 1, such that no step along the pathway reduced the organism’s fitness.
5. If I found such a pathway, and if there were sufficient time available in geological history for the pathway to have been traversed, I’d conclude that the wing wasn’t designed.
6. In the absence of such a pathway, I’d conclude that it probably was designed.
METHOD B
(A “second-best” method, much inferior to Method A. Could be used as a “stopgap” until detailed genetic data became available, but any conclusions reached via this method would be necessarily provisional.)
1. Identify the feature of the wing which appeared least likely to have evolved – roughly, the feature possessing the greatest (specific or irreducible) complexity. If I could then explain the evolution of that feature, it would be fair to conclude that the rest of the wing had evolved too.
2. In the absence of detailed information regarding the genes that give rise to that wing, I’d then look at the structural components of the feature identified in 1.
3. If I found that the components identified in 2 could be re-arranged so that the wing functioned in a more efficient manner, without interfering with the other bodily functions of the bird in question, and if I had no reason to suppose that the bird’s ancestors had ever possessed this more efficient functioning (i.e. if there were no evidence that devolution had occurred), then I’d conclude that the wing in question probably wasn’t designed.
N.B. The minimal “behavioral” assumption I’m making in step 3 is that an intelligent designer would arrange whatever components it selected to design with, in such a way that the structure it built functioned as well as it possibly could, given those components, without impeding any other bodily functions of the organism in question. In other words, any designer worth his or her salt should at least do the best he or she can with the materials he or she has selected.
4. Try to find a plausible antecedent for the feature identified in step 1 – i.e. the structure it supposedly evolved from.
5. If I found (by performing computer simulations) that the feature couldn’t plausibly have been built up step by step from its suuposed antecedent, or from any other plausible antecedent, without compromising the organism’s fitness, then I’d conclude that it was probably designed.
6. If I found that the feature in question was irreducibly complex, and that there was no plausible pathway by which the feature could have “devolved” from something which had more parts but was reducibly (instead of irreducibly) complex, then I’d say it was probably designed.
7. What would really perplex me is finding a feature where different considerations pulled me in opposite directions – i.e. where applying step 3 led me to believe that it hadn’t been designed, but steps 5 or 6 led me to believe that it had.
NOW HERE’S THE “METHOD” USED IN MOST EVOLUTION TEXTBOOKS TO ARGUE AGAINST INTELLIGENT DESIGN
1. Find an aspect of a complex structure that looks sub-optimal.
2. Don’t bother to rigorously test whether it actually performs sub-optimally; if it looks clumsy, that’s enough. It’s a kludge.
OR:
1. Find a complex structure, and then try to think of a way in which the function it performs could be improved, using different parts and/or materials. (After all, God can use any parts He likes, can’t He?)
2. Don’t bother to check if the “new and improved” design you imagined (using different parts and/or materials) would interfere with the other functions of the organism. If there’s a more efficient way to perform the function, then the structure performing it wasn’t designed.
Now that’s what I call lazy thinking.
vjtorley
But on what basis have you assumed it was designed in the first place?
Echidna-Levy
You wrote:
I haven’t. As I said, I’m a front-loader. While I believe that the first cell was designed for reasons discussed here, I’m fairly agnostic about subsequent features of organisms. When it comes to investigating a feature of organisms whose evolution we haven’t witnessed, I believe that agnosticism is an appropriate attitude until we get the big picture. That way, we avoid falling victim to our own philosophical preconceptions.
The ascription of design to a structure found in organisms is not an assumption but a conclusion. This conclusion is reached only when it appears reasonably certain that no plausible natural mechanism for generating that structure exists.
vj,
A well-documented rebuttal of the evidence provided to front-loaders by information coming from the ENCODE Project is doubtlessly going to follow.
…or perhaps some more charactor assasignation.
KF:
Oh, you mean like
“closed minded objectionist selective hyperskepticism”
or
“Darwinist Evo Mat”
You constantly complain about ‘oil of Ad Hominem soaked straw men’ and yet many of your posts seem to contain slurs against the people who are trying to debate with you as, instead of just addressing their points, you try and cast them as some evil curse on society, the root of all the modern worlds ills and appeal to ‘onlookers’ to adopt your blind disdain for anyone who questions your opinion or your twisted interpretation of facts.
You rarely address peoples arguments on their merits alone, your arguments are always cached in terms of your own presumed moral superiority and your opponents apparent immorality, and then fluffed up with clouds of cut’n'paste obfuscation – another thing which you preach against yet practice to excess.
And YES I am making personal criticisms of you because your impersonal behavior is so below the bar of enlightened scholarly discourse that it needs to be addressed. Now the real question is, do you have the honor and humility to apologize or is that aspect of Christianity something you prefer to opt out of?
That said you do such an excellent job of discrediting ID I could almost believe you were actually an Agent provocateur’.
Excession:
You have forgotten just one thing: I have shown, in responsible details [and have often linked], just what selective hyperskepticism is, and how/why it fails to be a sound approach to epistemology; with particular reference to the failure of Cliffordian-Saganian — “extraordinary claims require
extraordinary[ADEQUATE] evidence” — evidentialism. (And in fact, in so doing, I am self-confessedly giving a descriptive label to a pattern of fallacious thought ling since identified by Mr Simon Greenleaf of Harvard; who just happens to be a founding father of the theory of evidence. [So, it is not just a mere humble blog commenter you are trying to rebut . .. )Summarising from my proffered "definition" (description, really):
In short, your turnabout accusation-based argument manifestly fails.
You may also link references to me to make me out to be a hypocrite all you want; all you are achieving thereby in light of the actual balance on the merits, is to further exemplify just how routinely and habitually Darwinists seek to distract by using red herrings, led out to distorted strawmannish misrepresentations of arguments they oppose -- duly soaked in ad hominems -- and then proceed to ignite them to cloud the atmosphere, confusing, poisoning and choking it with polarisation. [Which is of course a classic extreme form of selectively hyperskeptical patterns of rhetoric.]
GEM of TKI
PS: Onlookers, you may wish to see my remarks on the underlying dynamics and circumstances at work here.
PPS: And, Sparc et al, I did not seek to “escape” from the just linked thread to here, but was about real world life after signing off from UD yesterday.
PPS: For those who want to see what ID methodology looks like, I suggest a glance here.
“do you have the honor and humility to apologize”
clearly not.
The definition of Selective Hyperskepticism you proffer describes your own position very well, thank you for making that clear.
In what way is calling you up on your behavior a distraction from the issue of your behavior?
I rest my case.
Excession.
Sadly, you are simply — and demonstrably — “wrong but strong.”
GEM of TKI
Echidna-Levy,
Yes but remember this discussion began with PaulBurnett commenting that Kiwi’s wings were an example of unintelligent design.
As for the second part, because apparently the answer is not obvious to you, the birds wing, along with feathers and the specialized avian lung, were designed. Extant birds may have lost some genetic information form the original design(s) to greater or lesser degrees depending on the selective pressure that they are under. Kiwis, for example, have lost a lot.
How do I know? Natural selection is barely able to conserve information, much less create it. Where a supposed evolutionary pathway requires more than two mutations to achieve the next selective benefit there is not enough reproductive power in a low reproducing organism like an avian to search the necessary mutational space to make such a genetic leap probable. For the bird’s wing, including feather and lung, it is improbable that any such mutational path exists, therefore, the wing, feather, and lung complex was designed.
Now this all a bit tedious because you continue to posture as if you have some ace bit of knowledge that will carry the day but all you do is ask questions that should be transparently obvious.