AiG Debunked: Fossils Fail to Find Major Transition From Dinosaurs to Birds

[TheNZThrower]

In an article published in October 8 2013, Answers in Genesis cite a 2013 study by Dececchi and Larsson, claiming that it proves that the longer forelimbs/wings of birds appear abruptly in the fossil record without prior precedent, as do their shorter legs. To quote them:

Larsson and Dececchi set out to determine from the fossil record when and how dinosaur forelimbs evolved into wings. Instead of finding a gradual lengthening, they found that when proportionate changes associated with different body sizes are factored out, there really is no such trend. The longer forelimbs, shorter hindlimbs, and long metatarsals (foot bones that are so long in birds they look like legs) appear abruptly in the fossil record. The skeletal characteristics of birds, in other words, start when birds start. They have no gradually transitioning antecedents in the rocks.

Extraordinary claims do require extraordinary evidence, and let's turn to Dececchi and Larsson and see what they have to say:

Research on their origin often focuses on the evolution of the wing with trends of forelimb elongation traced back through many nonavian maniraptoran dinosaurs. We present evidence that the relative forelimb elongation within avian antecedents is primarily due to allometry and is instead driven by a reduction in body size. Once body size is factored out, there is no trend of increasing forelimb length until the origin of birds. We report that early birds and nonavian theropods have significantly different scaling relationships within the forelimb and hindlimb skeleton. Ancestral forelimb and hindlimb allometric scaling to body size is rapidly decoupled at the origin of birds, when wings significantly elongate, by evolving a positive allometric relationship with body size from an ancestrally negative allometric pattern and legs significantly shorten by keeping a similar, near isometric relationship but with a reduced intercept.

So initially it appears that Answers in Genesis has correctly represented the findings of Dececchi and Larsson, right? Not so fast. As they themselves note, they included the transitional forms Archaeopteryx and Confuciusornis under the term birds, as indicated by their persistent referral to them as ''basal birds'':

We use the taxonomic terms Aves and Avialae as per Zhang et al. (2008). Avialae includes all maniraptoran theropods closer to modern birds than Deinonychus antirrhopus, whereas Aves is the clade containing the last common ancestor of Archaeopteryx lithographica and Vultur gryphus... [under section ''Relative Limb Lenths'']: Both Microraptor and Anchiornis had relative levels of forelimb elongation equal to those present in the basal birds Archaeopteryx and Confuciusornis.

Hence their cladistic definition of a bird is rather broad, as it includes the ancestral form of Archaeopteryx, which had distinctly saurian skeletal anatomy (such as a bony tail, teeth and claws), as does Confuciusornis with its clawed wings. In addition, Dececchi and Larsson also had the following to state about the body to limb proportions of Archaeopteryx in comparison to antecedent maniraptors:

Avians break the theropod appendicular scaling pattern in the forelimb and hindlimb. The forelimb scaling to SVL (Snout Vent Length, or the length from the tip of the beak to the posterior/arse) changes from negative to a positive allometry in birds. In Archaeopteryx, the most basal bird, this difference is not as pronounced, as it shares similar forelimb proportions to similar sized deinonychosaurians such as Microraptor, although its hindlimbs are relatively shorter. This may be linked to the limited flight capacity, if any, of Archaeopteryx compared to more derived basal avians such as Sapeornis.

As they noted that Archaeopteryx had similar forelimb proportions to prior non-avian dinosaurs, while having shorter legs, Dececchi and Larsson found that there did exist a transition in between the body to limb proportions of dinosaurs and birds, contrary to the claims of AiG.

So from what we can infer already, AiG is engaging in the standard creationist tactic when confronted with the existence of transitional forms; point to the new gap between the transition and the ancestor and declare that the transition must have appeared abruptly. Nevermind the fact that just because there doesn't yet exist a transition between the transition, it does not necessarily follow that such a transition is nonexistent as fossilisation is a rare event. Nevermind that given the sheer number of transitional forms between theropods and birds, it is rather arbitrary and difficult to draw a clear line as to when theropods became birds. As paleontologist John Long puts it in his book ''Feathered Dinosaurs: The Origin of Birds'':

The skeletons of the first birds looked so much like those of small predatory dinosaurs that even today it is difficult for dinosaur specialists to draw a clear line between them. In fact, it is entirely arbitrary where scientists choose to define the beginnings of birds. If, for example, the presence of feathers defined birds we would then have to include probably all the dinosaurs listed in this book as 'archaic birds' [Feathered Dinosaurs p.25].

Thus AiG prey upon the ambiguity of the transitions and distinctions between dinosaur to bird to claim that there existed a sudden jump in the fossil record from bird to dinosaur, when the paper they cited made no such claim.

Then AiG proceeds to demonstrate their lack of understanding of how traits are inherited:

So if dramatically longer forelimbs were so great, and long hindlimbs were such a hindrance they had to go, how do Larsson and other evolutionists explain where the genetic information for these innovations came from? Dececchi says that the abrupt appearance of these great evolutionary innovations were crucial to bird success. Yet nothing observed in biology reveals such novel information emerging through random natural processes. Evolutionists have never provided us with a proven biological mechanism for producing new genetic information that leads to the types of changes necessary for molecules-to-man evolution.

Now does AiG not understand what a mutation is? Do they not understand that allele frequencies vary? Do they also not understand that DNA, and by extension genes, make copies of themselves, and that the copying process is far from perfect?

Well, I guess when you're a young Earth creationist that seeks to defend the Bible's proclamations at all costs against all evidence, and refuse to admit that it can be wrong about anything, you have to avoid understanding genetics i.e. the mechanism that produces the raw material for evolutionary innovation. All you need to gain longer forelimbs and shorter hindlimbs is for the right mutation to occur. Shit, this is something observed even in humans, as some people are naturally born with longer arms or shorter legs than others. So contrary to the lie of AiG, we have observed that ''random'' natural processes can lead to longer arms and shorter legs within a multitude of species, as differing dog breeds and their differing leg lengths attest to.

If I missed out on anything or got any of the details in Larsson and Dececchi's study wrong, kindly point them out to me.

 

[jarlrmai]

All you need to know about AiG

Each permanent employee of AiG including people who work at the museum must sign a statement of faith (which includes):

"no apparent, perceived or claimed evidence in any field, including history and chronology, can be valid if it contradicts the Scriptural record"

 

[Hevach]

AiG plays a lot of games with terminology, and to understand what they're saying it's important to know the rules of their game. They use a few of their games here, the universal one they always play is that when they say "evolution," they mean something that is vastly more inclusive than mere biological descent, and also includes abiogenesis, deep time, the geological column, continental drift, deep sky astronomy, relativity, quantum and particle physics, and a number of other fields they feel, sometimes for very silly reasons, challenges their beliefs, and most importantly a faith based religion of their own invention that incorporates all these things as its tenets, hence their use of scientifically meaningless terms like evolutionist.

You've noted one of their games in their representations of Dececchi and Larsson, where they replace nuanced specific terms (like basal bird or nonavian maniraptoran theropod dinosaur) with simpler common words (bird and dinosaur), making the claim look far larger in scale than it really is. They also do the opposite, taking a word (like "abruptly") in an absolute form that isn't consistent with the full text of the source.

So here, the original paper is basically saying, "Pretty-Much-Bird Dinosaurs appeared from Not-Quite-Bird Dinosaurs quickly in a few steps." Which is not a scientifically shocking claim, particularly looking at the three species they use. All small feathered therapods, one which probably couldn't fly (but maybe could), one which might have flown, and one which probably flew (but maybe not).

By selectively diminishing or reinforcing words and presenting it without full context, AiG has turned it into, "Birds appeared from dinosaurs instantaneously from nowhere," which is meant to conjure to mind the image of a Stegosaurus egg hatching into a fully formed pigeon.

 

[JMartJr]

To give AiG their due, at least they strongly reject Flat Earth:

As I previously stated, the ignorance of many flat-earthers is astounding. But their ignorance often is surpassed by their arrogance. The term for arrogant ignorance is hubris. There is much pride among flat-earthers, at least among the vocal ones. It is pride that attracts people to flat earth in the first place. It is the self-congratulatory confidence that a flat-earther has found the deepest hidden truth that few people have found. If they have figured it out while most people have not, that must be evidence that they truly are far ahead of nearly everyone in understanding. That is the appeal of the secret knowledge of Gnosticism. But it is pride that keeps flat-earthers trapped. In order to escape the delusion of a flat earth, believers in such ideology must first realize that they have been duped by some very poor arguments. But this means that they aren't at the head of the class. Perhaps they aren't even the bottom of the class. They may be miles away from the school building altogether. This is humiliating, even to admit to oneself. But if a flat-earther has been vocal, coming out to friends and family as a flat-earther, this is even more difficult.

https://answersingenesis.org/astronomy/earth/reflections-flat-earth-movement/

 

[Andrew Eddie]

AiG plays a lot of games with terminology, and to understand what they're saying it's important to know the rules of their game.

They do, but it's fair to say I've seen a commensurate of game playing, though I would prefer the term "point scoring in the art of debating rather than fostering healthy, passionate debate over competing ideas". While I share some of the core beliefs of AiG or CMI, I find their increasingly combative nature as unpalatable as the celebrity anti-theists, both camps setting the science aside to promote personal world view biases.

For full disclosure I am a Christian and hold the faith position that the God the Christian Bible talks about did create the universe, but from a scientific point of view I don't identify as a "creationist" (because that is a loaded term that has many facets of nuance among Christian circles), I would identify as "a person that believes the probability that life was not engineered by intelligence is infinitesimally small" - the matter of whether that intelligence is God or not is outside the scope of scientific discussion, and frankly the Scientific Method doesn't give a damn anyway.

They use a few of their games here, the universal one they always play is that when they say "evolution," they mean something that is vastly more inclusive than mere biological descent, and also includes abiogenesis, deep time, the geological column, continental drift, deep sky astronomy, relativity, quantum and particle physics, and a number of other fields they feel, sometimes for very silly reasons, challenges their beliefs, and most importantly a faith based religion of their own invention that incorporates all these things as its tenets, hence their use of scientifically meaningless terms like evolutionist.

But this is the heart of the issue. What you are describing here is "what presuppositions do they bring to the table". That's not necessarily a bad thing, in fact, everyone does it and few people are good at communicating them, even fewer are willing to take the time to actually listen to the opponents reasoning.

Yes, they do use the broadest appraisal of the word "evolution", but in the same sentence you use "challenges their beliefs" and "faith based religion of their own invention" in the same, critical way - yes those phrases too are as meaningless as labelling someone either "creationist" or "evolutionist". Hang on, nobody is actually talking "science" yet are they, just calling each other names There are many example of scientists that have had their own beliefs challenged for good and bad reasons. Yes, Newton got a lot of gravity right, but Einstein challenged those beliefs ... and that was OK.

That all said, yes, I agree that AiG (CMI, et al) are bunkered down in their particular trench and they will paint any other Christian that doesn't tow their party line as not true believers or something worse. However, the same entrenchment can be seen on "the other side" and nothing really gets solved. It just becomes a game of debate survivor - it's not really science.

For me though, the issue is not whether bones can get longer or shorter (that's like arguing with a flat Earther over the amount of curvature they can or can't see over a single mile), but does the scientific method even have a framework for trying to explore the question of are we an accident or not. That's the intellectual discussion I'd like to actually have, albeit heading off topic.

 

[Mendel]

does the scientific method even have a framework for trying to explore the question of are we an accident

You may be interested in this topic, then: https://www.metabunk.org/threads/conversations-with-materialists.12002/

 

[NorCal Dave]

They do, but it's fair to say I've seen a commensurate of game playing, though I would prefer the term "point scoring in the art of debating rather than fostering healthy, passionate debate over competing ideas". While I share some of the core beliefs of AiG or CMI, I find their increasingly combative nature as unpalatable as the celebrity anti-theists, both camps setting the science aside to promote personal world view biases.

For full disclosure I am a Christian and hold the faith position that the God the Christian Bible talks about did create the universe, but from a scientific point of view I don't identify as a "creationist" (because that is a loaded term that has many facets of nuance among Christian circles), I would identify as "a person that believes the probability that life was not engineered by intelligence is infinitesimally small" - the matter of whether that intelligence is God or not is outside the scope of scientific discussion, and frankly the Scientific Method doesn't give a damn anyway.


For me though, the issue is not whether bones can get longer or shorter (that's like arguing with a flat Earther over the amount of curvature they can or can't see over a single mile), but does the scientific method even have a framework for trying to explore the question of are we an accident or not. That's the intellectual discussion I'd like to actually have, albeit heading off topic.

As someone that grew up in church and was a Bible study leader for many years, the problem eventually becomes "What, or Who is God?" If God is defined by the Bible, and like me, one starts to find multiple problems with the Bible, then one finds multiple problems with God.

Nevertheless, as @Mendel talked about above, the thread from last month is more along the lines of what your looking for I think. I seemed to have missed it completely and will have to try to continue binge reading it latter, at lunch. Be advised, it goes to many pages and even in page one it drifts off into Italian tax law, something that can happen on these more open ended threads.

 

[Mauro]

Be advised, it goes to many pages and even in page one it drifts off into Italian tax law, something that can happen on these more open ended threads.

The drift to Italian tax law was my fault The thread gets better further on.

 

[Craig2000]

John Sailhammer's book is compatible with Genesis and big bang cosmology. But Adam had to be created directly by God. I'll probably get deleted though.

 

[Mendel]

John Sailhammer's book is compatible with Genesis and big bang cosmology. But Adam had to be created directly by God. I'll probably get deleted though.

Well, it would help if you gave the title of the book and some quotes that support your claims. I don't even understand how John Sailhammer is related to this discussion.

 

[Craig2000]

It's not that hard.