A critique of BibleLife.org’s article about bird evolution

I’m posting this because I promised Jan87676 in this thread that I was going to refute what he posted there about bird evolution. But while I was at it, I figured I’d also refute the rest of the BibleLife.org’s article about this, since it’s been a while since the last time I posted a big refutation of a PRATT list here. The original article can be found at http://www.biblelife.org/evolution.htm.

This is an oversimplification, but no major problems here quite yet. On to the next paragraph…

Its seems as though the person who wrote this article never even read a children’s book about the origin of birds, since that would have been enough for them to learn that paleontologists have never suggested the existence of the sort of half-sized wing described here. The evolution of wings went through a few stages, each documented by fossils, which are as follows.

Stage 1: grasping forearms


(Drawn by Robert Gay)

Most people probably wouldn’t consider this a wing, but I’m including it for completeness’s sake because it’s what wings were developed from. This is from the dinosaur Coelophysis bauri, an early theropod (carnivorous dinosaur) from about 225 million years ago. Like most theropods it was bipedal, which freed its forelimbs to be used for capturing and holding onto prey.

Although this doesn’t resemble a bird’s wing very much, its skeletal anatomy is already fairly similar to what’s found in birds. For example, this animal’s clavicles had been fused into a furcula (or “wishbone”) because this helped it to hold onto its prey. Unfortunately, I was unable to find a picture of this.

Stage 2: grasping forearms with insulatory feathers



This dinosaur, Sinosauropteryx prima, still had arms that were functionally pretty similar to what Coelophysis had. Unlike Coelophysis, however, its fossils preserve a covering of hair-like filaments that were probably used as insulation. When this dinosaur was discovered in 1996, it was the first direct evidence of anything of this nature in a non-avian theropod, lending support to a theory proposed ten years earlier by Gregory Paul and Robert Bakker that the first feathers evolved in dinosaurs for a purpose unrelated to flight.

Here a couple attempted creationists rebuttals about this, and the problems with them.

1: These might not really be primitive feathers; maybe they’re collagen fibers or the sort of frill found on the back of an iguana.

Upon closer examination, though, it’s clear that this isn’t the case. Unlike collagen fibers, these filaments are visibly hollow, and occur in the wrong places on the animal to be an iguana-like frill. While this sort of frill also occurs only in a single line along the backs of animals that have it, there are overlapping layers of these filaments visible along the back of Sinosauropteryx, and the fossil’s counterslab shows them extending down the animal’s sides also.

2: Sinosauropteryx lived after the earliest known bird (Archaeopteryx) so it must be irrelevant to bird evolution.

It’s true that Sinosauropteryx lived later than the first birds, but this fact isn’t as significant as creationists make it out to be. Nobody is claiming that Sinosauropteryx is a direct bird ancestor, but only that it shows an example of the type of animal from which birds evolved. Birds would have been descended from an earlier animal similar to this, such as Compsognathus. The reason I’m using Sinosauropteryx as an example instead of Compsognathus is because skin impressions of the latter have never been found.

Stage 3: grasping forearms with fringes of contour feathers



This dinosaur, Caudipteryx zoui, has hands with a skeletal structure more similar to that of birds than Sinosauropteryx’s is, but the most important difference is that its feathers have developed into long plumes that were probably used for displaying to rivals or potential mates. These are preserved on both its arms and tail. These feathers show interlocking barbs and barbules, the same as exist on modern birds. However, because of the symmetry of these feathers and the short length of Caudipteryx’s arms relative to the size of its body, it’s unlikely that Caudipteryx could fly.

An attempted creationist rebuttal: What if this is just a flightless bird?

Gregory Paul, a legitimate paleontologist, has proposed this theory also. But what creationist fail to realize about this is that if Caudipteryx is a bird, it has so many traits associated only with nonavian dinosaurs that it would have had to regain several features of dinosaurs that aren’t present in birds. This would only have been possible if birds were descended from dinosaurs, and still had some of the genetic code for the traits that were being regained. Two of this animal’s most notable uniquely dinosaurian features are its forward-pointing pubis, and the contact in its ankle joint between the calcanaeum and the fibula.

Stage 4: gliding/early flying



This animal, Microraptor gui, has asymmetrical feathers. This is an adaptation that modern birds use to ensure that they push themselves up with each downstroke of their wings more than they push themselves down with each upstroke, so it means that Microraptor gui was probably capable of a primitive form of powered flight.

This animal is unique in that it had flight feathers on both its front and hind limbs, which is something that William Beebe hypothesized approximately 100 years ago would have existed in the ancestors of birds. However, its legs lacked the muscle arrangement that would have been necessary for it to flap the “wings” on them, so these were probably used primarily for gliding. This, and the type of environment in which Microraptor gui lived has led paleontologists to conclude that it was arboreal, and used its wings to glide from tree to tree in the same manner as a flying squirrel.

This provides some insight into the development of flight. Young birds of some species are able to use their wings as an airfoil to press themselves onto tree trunks in order to help them climb, so this is one possible use for primitive wings in an arboreal dinosaur. Eventually this method would have been combined with gliding in order to lengthen and steer its leaps, until it was able to remain airborne under its own power.

Two of the main creationist claims about Microraptor are that it’s actually a bird, and that it lived too late to be a bird ancestor. Since I’ve already dealt with these claims about Sinosauropteryx and Caudipteryx, the main point I’m going to address about this is AiG’s argument about wings being used for traction: But it makes no sense that natural selection for traction should lead to flight. Rather, on the face of it, traction would require the opposite force to lift, so the selective direction would be away from flight.

However, this shows a lack of knowledge about how the method of using wings for traction actually works. Birds that do this tilt their bodies towards the surface they’re climbing, so that their wings push them forward rather than up. By inclining their bodies the opposite direction, they could alternatively use their wings to push themselves away from the surface in order to take off from it. This is similar to the way a spoiler works on a race car: it’s essentially the same structure as an airplane wing, the only difference being that it’s used to push a car down rather than push an airplane up.

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Continued…

Stage 5: the first birds



I probably don’t even need to say what this animal is, since it’s the most famous of all the transitional forms between dinosaurs and birds: Archaeopteryx. There are two known species of Archaeopteryx, A. lithograhica and A. baravica. I’ll explain in a minute why this is important.

Under the Linnaean system of taxonomy, this is both the earliest known bird, and anatomically the most primitive. Creationists have a tendency to make a big deal out of the fact that it’s classified as a bird rather than a dinosaur, despite the fact that there’s essentially an arbitrary distinction between the two. This animal is no more different from Microraptor gui than a leopard is from a cheetah, and the only reason why Microraptor is classified as a reptile and Archaeopteryx as a bird is because the Linnaean system forces a line between the two classes to be drawn somewhere in this transition.

Like Microraptor gui, both species of Archaeopteryx have asymmetrical flight feathers. Archaeopteryx also had fairly well-developed flight muscles that attached to its furcula, which probably would have been enough for it to fly short distances. However, in almost every respect it retains the skeletal anatomy of a theropod dinosaur, and specimens of it have initially been misidentified as belonging to the dinosaur Compsognathus on two separate occasions.

This is the aspect of Archaeopteryx that creationists attack most often: they claim that it’s merely a bird, with nothing uniquely dinosaurian about it. However, this overlooks quite a few important traits it has in common with dinosaurs that are atypical of birds:

1. It has teeth. Teeth are present in almost all theropods (with only a few specialized exceptions, such as oviraptorids) but not in any modern birds.
2. It has ventral ribs (gastralia). This is typical of reptiles and dinosaurs, but not birds.
3. It lacks a triosseal canal, the pulley-like shoulder joint that enables modern birds to take off from the ground by performing a wing flip. Instead, the shoulder joint of Archaeopteryx has the same structure as that of theropod dinosaurs.
4. Its spine enters its skull from the rear, rather than the bottom. This is typical of dinosaurs but not birds.
5. It doesn’t have a carinate (keeled) sternum. Archaeopteryx lithographica doesn’t have a sternum at all; all it has is a pair of unfused sternal plates, which are found in most theropods but no modern birds. These plates are fused in Archaeopteryx bavarica, but the sternum still doesn’t have a carina. The only modern birds that lack a carinate sternum are those that either lost the ability to fly early in their evolution (ratites), or those that lost it secondarily because of a unique lifestyle, such as the Hoatzin.
   
   EDIT: a friend of mine just told me about a new study I wasn’t aware of, suggesting that what was previously identified as the sternum of A. baravica may have in fact been one of its coracoids. If this is correct, both species of Archaeopteryx probably had unfused sternal plates instead of an ossified sternum. My main point remains the same, though: there are no living birds that have this.
   
   The article about this new study is at http://dml.cmnh.org/2005Feb/msg00544.html.

There are more than 20 uniquely dinosaurian traits present in Archaeopteryx, but I don’t have the space to list them all here. Talk.Origins has a more complete list at http://www.talkorigins.org/faqs/arch...ptile-features

One other creationist claim about this: “Maybe Archaeopteryx is a forgery created to provide false support for Darwin’s theory of evolution.”

There are too many problems with this claim to list, but the most obvious is that the Teyler specimen of Achaeopteryx was discovered about four years before Darwin published his theory. If the creationists claiming this were correct, someone would have had to forge this fossil in an effort to support a theory that didn’t exist yet. Although Answers in Genesis does not recognize the problems with the “it’s just a bird” argument, they’ve recognized that the forgery argument is so obviously false that they’ve asked creationists to stop using it.

One other thing worth pointing out about this is that in November of 1999, National Geographic published an article about a feathered dinosaur that was indeed a forgery, which had been given the name “Archaeoraptor”. However, the Chinese peasants responsible for this hoax created it only because they wanted to increase the market value of the fossil, not to provide unwarranted support for evolution. The two fossils from which this chimera was constructed, Yanornis martini and Microraptor zhaoianus, are important enough transitional fossils in their own right that they would have provided stronger evidence for the dinosaurian ancestry of birds if they had been kept separate.

Before I move on to the rest of BibleLife’s article about bird origins, I’d like to point out that none of these fossils actually prove the existence of an evolutionary link between dinosaurs and birds. Outside of mathematics, it’s impossible to prove anything with 100% certainty. However, the theory that birds are descended from dinosaurs explains this evidence in a way that no other theory can, and the only alternative explanation for a creationist is that God created this evidence with the specific intention of deceiving us. And if you’re going to claim that God is a liar, Whether or not the theory of evolution is true is likely to be the least of your worries.

Here’s the rest of BibleLife’s article:

As should be clear from my description of the five stages in the evolution of flight, the author of this article has reversed the order in which this transition occurred. Grasping hands didn’t develop from wings; it was the other way around. I think the explanation I’ve already provided is sufficient too show what’s wrong with this claim.

I swear I’m not making this up—the original article actually contains this image. Perhaps at some point, Warner Brothers can be persuaded to shut down BibleLife.org for violating their copyright.

Other than the same displays of ignorance that are found throughout the article, there’s one other claim here that’s worth addressing. No paleontologists currently hold the theory that hollow bones originally evolved in dinosaurs for the purpose of flight. As early on as stage 1, in dinosaurs such as Coelophysis, their bones were becoming hollow simply because the improvement in agility this brought them made it easier for them to capture prey. This eventually became one of the traits that enabled dinosaurs to evolve flight, but the animals in which it first evolved never planned for this to happen.

This presents a flaw in ID theory’s claim about “irreducible complexity”. ID theorists have used flight in birds as an example of something that couldn’t have have evolved because it wouldn’t be possible without several different elements working together, none of which would have been useful for flight on its own. What this theory fails to take into account, however, is that in most cases of “irreducible complexity” these sorts of traits originally evolved for purposes completely unrelated to their current use. In the case of bird evolution, flight became possible in theropod dinosaurs as a result of several different traits they had evolved for the purpose of display, predation, and mobility.

The BibleLife article goes on to make some other ignorant claims about sauropods, the origin of dinosaurs, and how sea animals emerged onto land. But considering that I’ve spent over three hours on this and it’s already so long I’m having to split it into two parts, I think I’d better leave it up to other people here to refute the rest of this site’s PRATT list.

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This thread got NO replies? I was hoping at least a few YECs would show up here to tell me I’m a tool of Satan or something like that.

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Of course not. The resident creationists know when a LCW has been thoroughly pwned and avoid the death scene like the plague.

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I take a stand on justice, I take a stand on race
Gonna take me a TV evangelist and punch him in the face
I sing about the hope that’s in me and ask why the poor aren’t fed
But if I don’t tow the party line, it’s be better if I were dead

I’m a liberal backslider I’ve been sliding ‘bout ten years
People ask me how I’m doin’ and I confirm all their fears
I’m swearing like a trooper, and I’m drinking like a bum
I'm a liberal backslider, and it sure is a lot of fun

LCW? I haven’t heard that acronym before. What’s that?

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Lying Creationist Weasel.

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I take a stand on justice, I take a stand on race
Gonna take me a TV evangelist and punch him in the face
I sing about the hope that’s in me and ask why the poor aren’t fed
But if I don’t tow the party line, it’s be better if I were dead

I’m a liberal backslider I’ve been sliding ‘bout ten years
People ask me how I’m doin’ and I confirm all their fears
I’m swearing like a trooper, and I’m drinking like a bum
I'm a liberal backslider, and it sure is a lot of fun

Ah, I should have known.

Is there anything else I can do with this so they’ll at least read it? Should I post it in the Quiet Thread?

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You're right though:

that was way too long

Anyway, I think that pictures are always good. You already provided 2 photograps of fossils, but replacing the drawings by actual photographs (or, if the photographs are a bit unclear, just posting both) would make your post more "believable" at first glance.

My post was? I don’t think I could have gone into enough detail about this with anything shorter, though.
For some reason, it’s extremely difficult to find photographs of most of these fossils. I spent over an hour searching for them with Google (as well as at some well-known paleontology sites) but eventually decided I’d just have to settle for drawings of most of them.

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I very much liked your posts. It's too technical though, which is why it will be ignored by most creationists. They don't like detailed arguments.

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