So I was on a panel discussion about micro vs. macroevolution…

Several weeks back I get an email from Phil Calderone, a member of one of the local atheist/agnostic/freethought groups (I.E.A.A.), asking if I would like to act as a fill in on a (then) upcoming “believers vs. non-believers” panel discussion on the subject of micro vs. macroevolution. Apparently, one of the persons originally invited was not going to be able to participate and he needed a fill in and was pointed towards me by Dr. Brad Hughes, who many years ago I had helped (along with others) prepare for a debate with “Dr.” Kent Hovind.

After some trepidation—due to having never done any public speaking before—I agreed to participate as long as it was understood that I was unlettered and neither a paleontologist or biologist but rather a mere amateur naturalist who has had a bit of experience in the creation/evolution debate. 

The format of the discussion was meant to be a relatively informal back and forth between four people with two on each side. One the “believers” side there was a gentleman named Kelly Clemensen, of something called the Areopagus Project, and Dr. Paul Giem of Loma Linda University (see also Giem’s web page here). On the non-believers side was myself and Phil Calderone who was to moderate but had to fill in the second non-believers chair for another person who couldn’t make it.

I will not go into any more description of the event as it was recorded on video and you can watch the proceedings for yourself below. However, truth and honesty before all I will be addressing at least two places where I know I screwed up in the discussion below the video.

Please feel free to point out any other mistakes I made, or address the many points made by the creationists that went unaddressed by either Phil or me during the discussion. I know there are whole bunches of things that our opponents said that was missed or deserved more in depth dissection.

Now that you have, hopefully, watched the video there are two places that I realized I messed up pretty much right after the debate. One was minor memory failure, misattribution about punctuated equilibrium. The other was a more significant—at least in my opinion—point were I brought up a group of fossil organisms that was really something of a red-herring—though I committed the fallacy out of partial ignorance—and should have known better from other statements I myself had made at other points in the same discussion!

Read on»

Creationism Nit: Archaeoraptor?

So the other day I found myself near one of the local Bible book stores and since I had the time wandered in to see what creationist fare they might have in their apologetics section. As it turned out not a lot, however in the homeschooling section they did have this little tome titled, Exploring the world of biology: From mushrooms to complex life forms (2009) by a John Hudson Tiner and published by Master Books (which as far as I know is still a subsidiary of the Institute for Creation Research):

the-world-of-biology-tiner

I am not sure why Mr. Tiner—who is apparently a math teacher—chose to start with mushrooms in his “exploration” but even leaving out simpler organisms makes his exploration a tall order when he only has 160 pages to work with.

Regardless, I am not here to critique the entire book, or even the section from which I have drawn my nit (I couldn’t do so in good faith anyway, as I only flipped through the book and took a couple quick photos). I am only here for the nit, nit, nit!

And the nit is this from page 133:

archaeoraptorHere we have a black and white photo of a fossil which is labeled Archaeoraptor liaoningensis.

Huh, yeah, it is just that the problem is the picture is not of that notorious fraudulent fossil. See for yourself; compare the picture above with following illustration of the actual Archaeoraptor: 

(Pickrell 2015)

You don’t have to have a degree in comparative anatomy to tell these two specimens apart.

What Tines has done is publish what is clearly a cropped photograph of the Berlin specimen of Archaeopteryx siemensii perhaps the single more famous and recognizable fossil in the worldand mistakenly labeled it as Archaeoraptor.

Archaeopteryx siemensii

The Berlin specimen of Archaeopteryx siemensii

So, yeah, “oops!” Mr. Tines may want to familiarize himself with Archaeopteryx before he opines on the state of the fossil evidence for the evolution of birds from other dinosaurs (let alone starts writing books that might fall into the hands of impressionable children). 

For more info on the Archaeoraptor story see:

Archaeoraptor Fossil Trail” By Lewis M. Simons from the October 2000, National Geographic magazine

Archaeoraptor illustration source:

Pickrell, John (2015) The great dinosaur fossil hoax, Cosmos (website).

Responding to a comment on my article: “Gill slits” by any other name…

I have decided to move this up from the comments section (cuz why not?) of my article “Gill slits by any other name…

Andy: Hi Troy, I read your post, and it is very well argued.

Thanks. [He said knowing that a “but” was coming.]

Andy: At the moment, I am a biology student at a local university, and one of my personal headaches is the promotion of either creation-ism or evolution-ism. To be honest with you and with all due respect, I really don’t care for either explanation.

Andy, with all due respect, you should know that for someone like me who has been in the “trenches” debating people pushing pseudoscience for years, the fact that you would refer to evolutionary theory as “evolutionism” is a large red flag that would strongly lead me to suspect that your understanding of evolutionary theory and science itself is likely wanting.

Unfortunately, your next sentence does little to disabuse me of my suspicion. Creationism is set of theological beliefs regarding a creation story written down in the 6th or 5th century B.C.E., accepted on faith and in the face of contravening facts by a tiny minority of people with any scientific background. Its mechanisms (God did it) are untestable and to the extent that it makes claims testable against the empirical world it has been falsified a thousand times over.

On the other hand evolutionary theory is a scientific explanation for a vast number of facts that is testable against further observations of the empirical world and used by the vast majority of the relevant scientific community as a guide to further research…whether you “care” for it or not.

That you would casually place them on the same level is yet another huge red flag.

Andy: As a student, the only thing that I am concerned about is true scientific facts that have been tested at a laboratory to the molecular level.

We are only three sentences in and we have three red flags. In my experience people who use terms such as “true scientific facts” (as opposed to what, “false scientific facts”?) tend to not to be particularly familiar with either the facts or what counts as scientific.

However, that is a nit compared to the philosophical problems with your above statement. Why on Earth would you limit yourself to what is testable in a laboratory at a molecular level? Better yet, why should anyone else take your narrow limits as to what to be concerned with seriously? Using your bizarre limitations, we would be throwing out vast swaths of empirical data, and not just in biology.

Molecules are great but they are not a perfect path to knowledge nor are they the only path.

Furthermore, the point of science is not simply collecting random facts, rather it is about explaining the facts that we observe [insert Darwin quote about collecting pebbles here]. In this case, we have detailed anatomical, physiological and genetic similarities between the pharyngeal structures of terrestrial vertebrate (hereafter “amniotes“) embryos and non-amniote vertebrates (amphibians and “fish”), set against a particular paleontological backdrop that needs a coherent explanation.

You do not like creationism, great. That should be a given and I am with you. However if you do not like evolutionary theory, then what is your better explanation for the gill-like appearance of the pharyngeal structures of amniote embryos (and everything else evolution explains)?

You cannot just sit back and say, “I don’t buy any of it” and expect to be taken seriously, especially in face of the apparent success of evolutionary theory.

Andy: My teacher presented this same example about the gill slits during a microbial genetics lecture.

I am not sure how the “gill slits” of vertebrate embryos are relevant to the genetics of microbes but OK…

AndyI was just exhausted of listening, so, I raised my hand and said that the information was outdated and more up-to-date data has been collected explaining that they are no longer gill slits, and they are pharyngeal pouches.

Huh, did you read my article to which you are supposedly responding? You are literally arguing semantics here. Regardless of what we call these structures in the embryos of amniotes, they exist, they resemble—in detail—the developing gills of non-terrestrial vertebrates, and we want to understand why this would be so.

AndyHe asked what was my source, and my reply was, with all due respect, professor, but your source is 150 years old and newer information was out that did not concentrate on a belief based teaching. He stopped and said he will do some more research and get back to us. He continued with the lecture as it was intended.

I am sorry but “your source is 150 years old”, even if true, is not an argument; old ≠ incorrect. FA = -FB (for every action there is an equal and opposite reaction) gets robotic probes to Mars despite the fact that Newton came up with the formula over three hundred years ago.

Furthermore, what is this “belief based teaching” to which you refer? Once again, if you read my article you would know that referring to these structures as “gill-slits” is not dependant on a belief in either creation or evolution as is evidenced by the fact that pre-Darwin creationists called them this.

Oh, and what is your source Andy?

AndyI agree; they look like gills until you dissect it, and then they look like pouches. I know in biology we name a lot of things base on morphological characteristics, and that is a great easy way to remember things.

No, no, no, again did you even read my article? Here, look at this diagram again:

Source bionalogy.com, with modifications.

Source bionalogy.com, with modifications.

There are clefts (or grooves) on the outside of the pharynx (red arrows) with corresponding pouches on the inside (blue arrows). These clefts and pouches are each separated by membranes that, in mammals, normally remain unperforated with the first (tympanic) membrane forming the so-called eardrum. Some of the post tympanic membranes do normally perforate and then reclose in some birds and reptiles embryos. They also temporarily perforate in the gill-bearing larvae of some amphibians and, of course, in fish they stay perforated and become gills.

Since I know some people are queasy about diagrams here are a few photographs of coronal sections done on various mammal embryos. First, an electron microscope picture of what I think is a stage 13 human embryo (Etchevers, 2008)(blue arrow points to the pharyngeal pouch and red to the corresponding cleft).

(Etchevers, 2008)

For comparison, here are some stained sections from a mouse (left, Zhang et al. 2005) and a pig (right, Shone & Graham 2014) at a similar point of development; once again blue arrows for pouches and red for clefts. Also, note in these photos that the aortic arches—the blood vessels—are visible within the pharyngeal arches (green arrows).

(Left, Zhang et al. 2005 – right, Shone & Graham 2014)

These are not just “pouches”! There are arteries (the blood vessels shown above), muscles, nerves and cartilaginous structures found on either side of the cleft/pouch pairs in the embryonic gills of “fish” and the corresponding pharyngeal arches of amniote embryos.

How do you get from this to, “they look like gills until you dissect it, and then they look like pouches” without ignoring all of these observable facts? These things exist and you need to explain them Andy.

AndyThe only thing that really gets to me is that either creationist or evolutionist keeps trying to push the subject in school.

The reason a competent science teacher (i.e. one who teaches evolutionary theory) would bring them up is because they are structures that have interested biologists since they were first discovered and whose existence is elegantly explained by descent from a common ancestor (evolution).

AndyHonestly, I paid for one of my books close to $300. I feel that my book should be filled with up-to-date information that has been tested, and that is going to help me in the future and not filled with propaganda of any kind.

The pharyngeal structures of amniote embryos are not propaganda. They exist and are observable by anyone with eyes to see. For example, please note that the photographs of the pharyngeal sections of mouse and pig embryos I reproduced above were both taken from papers published within the twenty-first century. Any modern textbook on vertebrate developmental biology is likely to have similar photos or diagrams of these structures.

AndyI guess it is easier to print the old stuff than to update the books to what they are intended to do, and that is to provide useful information that can help us treat diseases and give our patients a fighting chance.

Sorry Andy regardless of whether it comes from an older source or a current one, pharyngeal clefts, or “gill slits” exist in amniote embryos whether or not you want to accept the facts or the current best explanation for them, so please spare us the overwrought “won’t someone think of the ill people?!” shtick.

AndyTo this day, I haven’t seen a mermaid or an angel either in nature or in a lab, so, I will have to dismiss both claims as pending research and proper laboratory testing.

53435573

Yeah so at this point, I am starting to have doubts that you are for real Andy and not just a troll looking for attention. What the hell does a mermaid have to do with anything Andy? Please tell me you are not seriously suggesting that evolutionary theory somehow supports the existence of mermaids [Hint: the exact opposite is the case]. Because if you think it does, you may want to rethink your career path—perhaps something in the arts?

AndyPlease don’t take this the wrong way. I am a paying student who is discordant with the never-ending stories.

As I said, after the mermaid comment I am no longer sure how to take you Andy. Perhaps your response or lack thereof will clarify that question.

Regardless I want to thank you Andy. Formulating my response to you has made me consider adding a few things to my “gill-slit” article that I think could use some expansion or clarification. So anyway, Poe, troll or sincere, something positive has come from your comment, thanks.

References

Etchevers, Heather (2008) Development of the branchial arches (slide presentation downloaded on 10-29-16)

Shone, Victoria & Graham, Anthony (2014) Endodermal/ectodermal interfaces during pharyngeal segmentation in vertebrates, Journal of Anatomy, 225(5):479-91

Zhang, Zhen et al. (2005) Tbx1 expression in pharyngeal epithelia is necessary for pharyngeal arch artery development, Development, 132:5307-5315

Secular Museum Blunder

To demonstrate once again that I am an equal opportunity critic, here is a nit I have to pick with a secular museum, namely the Riverside Metropolitan Museum located in downtown Riverside, CA. It is a small museum and most of its limited public floorspace is taken up by displays dealing with Native American culture and artifacts. However it also has a number of displays on natural history, primarily that of the mountains & deserts in Riverside County. It is near some of these displays I found the following stuck to a wall:

Rhamphorhynchus_at_RMM

And here is the lone label seen in the bottom right-hand corner:

Cuviers_pterodactyl

It reads, “Baron Cuvier’s Pterodactyl“, apparently a reference to the fact that it was the “father of paleontology” Georges Cuvier who dubbed one of the earliest discovered pterosaur fossils “Ptéro-Dactyle”.

Yeah, the problem is though the cast of the fossil accompanying the label is very clearly not of the genus Pterodactylus named by Cuvier. Rather it is a cast of a RhamphorhynchusHere for comparison is the holotype specimen of Pterodactylus:

Pterodactylus_holotype_w-arrow

The red arrow points to Pterodactylus’ rather diminutive tail, which stands in rather stark contrast to Rhamphorhynchus’ long kite-like tail which ends in a diamond shaped vane (see above). 

Amusingly this is not the first time that these two genera have been confused. Apparently Rhamphorhynchus was originally misidentified as a species of Pterodactylus but after a few rounds of reclassification finally ended up as its own genus by the hand of Richard Owen 1861.

So a wag of my finger to the Riverside Metropolitan Museum; you need to fact check your displays.

Consilience and whale evolution

Way, waaay back in December of 2005 (ye gods has been ten years already?!) I wrote a Feedback response on the Talk Origins Archive to a question about the vestigial pelvic bones found in modern whales. In this case the questioner did not believe them to be truly vestigial, no doubt due to holding erroneous beliefs regarding the subject. In my response I of course took the time to correct their faulty views, however I also used the opportunity to talk about the concept of consilience wherein multiple independent lines of evidence converge on a single explanation, giving us greatly increased confidence that those explanations (hypothesis/theories) are likely to be accurate reflections of reality, i.e. “true”. 

I have now and again thought of going back and using that post as a spring-board for a more detailed examination of this subject and who knows, I may still do so someday. In the meantime however, here is a great video from Stated Clearly that I ran across on Facebook recently that uses the same topic—whales—to essentially do the same thing I did all those years ago; make a point about the consilience of evidence pointing to a pretty definite conclusion with regards to not just the ancestry of cetaceans but the evolution of life in general. Better they include more details than I did and it has animations.

Check it out:

I miss answering the feedback question on Talk Origins…

Creationism Nit: Archaeocete legs

This will be a departure from my typical novel length dissection of a creationist article and will instead be a short look at a single creationist gaffe. Perhaps I will make this into a series, we’ll see. Anyway, today’s nit will be picked with young Earth creationist Dr Carl Werner (a medical doctor).

I recently acquired a copy, of what I believe is the 1st edition, of his book Evolution: The grand experiment (2007, 2nd printing 2009, coauthored with his wife Debbie Werner) and while skimming through it I noticed a little error on page 57, which is chapter 5 of the book and is apparently meant as a refutation of the evidence for evolution from comparative anatomy. In this particular case he is discussing the homology of various tetrapod forelimbs (yellow highlighting mine):Werner_whale

The “nit” in this case is his illustration of the forelimbs of a whale in the dark blue circle above. When I saw it I immediately  recognized that it was not in fact the forelimbs of a whale but rather the hind limbs of one. In this case those of an extinct archaeocete, most likely those of Dorudon (image source).

The skeleton of Dorudon.

And these are the hind legs of Dorudon (image source):

Dorudon hind legs at the Smithsonian Museum

For comparison here are a couple modern whale forelimbs:

Blue whale (Balaenoptera musculus).

Pacific white-sided dolphin (Lagenorhynchus obliquidens).

Clearly what Dr. Werner has pictured are not the forelimbs of a modern whale, rather my money is on them being the hind limbs of Dorudon. Is it a huge deal? No. It is just another example of sloppy creationist research (I mean if a printing press operator recognizes archaeocete legs when he sees them, come on).

Nit. Picked.

Relevant Links

Answers in Genesis memory holes a glaring error but fails to notice others

While doing some research for a potential post, I was going back and reviewing some of the obvious and indisputably false statements made by creationists that I have documented here on PCwP and in doing so discovered that Answers in Genesis has relegated one of these blunders to the memory hole.  In this case, it seems that AiG would rather we forget that their in house “anatomist”, Dr. David Menton, apparently cannot keep his saurischian (“lizard hipped”) dinosaurs and his ornithischian (“bird hipped”) dinosaurs straight—a basic distinction that any child interested in dinosaurs knows.

This by itself would be reason enough to revisit Dr. Menton’s article however an even better reason might be the fact that the interwebs is currently abuzz with the news that Bill Nye (The Science Guy) has agreed, perhaps unwisely, to debate creationist preacher Ken Ham—Dr. Menton’s boss at AiG—this coming February 4th (2014). I believe what follows should give the reader some insight into both the commitment to principled scholarship and the scientific caliber of the people behind Answers in Genesis.

Now You See It, Now You Don’t

As I noted in back in my February 2009 post,Four and twenty sauropods baked in a pie“, Menton erroneously identified sauropod dinosaurs—long necked giants like Apatosaurus, a.k.a brontosaurus—as being “bird-hipped”, or ornithischian, dinosaurs, making a point of how un-birdlike these massive dinosaurs were, in an article titled “Did Dinosaurs Turn Into Birds?“.

Here is how this section of the article read at the time:

Menton: All dinosaurs are divided into two major groups based on the structure of their hips (pelvic bones): the lizard-hipped dinosaurs (saurischians) and the bird-hipped dinosaurs (ornithiscians)[sic]. The main difference between the two hip structures is that the pubic bone of the bird-hipped dinosaurs is directed toward the rear (as it is in birds) rather than entirely to the front (as it is in mammals and reptiles).

But in most other respects, the bird-hipped dinosaurs, including such huge quadrupedal sauropods as Brachiosaurus and Diplodocus, are even less bird-like than the lizard-hipped, bipedal dinosaurs such as the theropods. This point is rarely emphasized in popular accounts of dinosaur/bird evolution. [Emphasis mine]

This conspicuous blunder, of both taxonomy and comparative anatomy, remained on the AiG site for about five years, then somewhere between April 19th and May 22nd 2013—going by the snap-shots the Internet Archive Wayback Machine takes of websites—they quietly changed this part of the article to read thusly (changes in bold):

Menton: All dinosaurs are divided into two major groups based on the structure of their hips (pelvic bones): the lizard-hipped dinosaurs (saurischians) and the bird-hipped dinosaurs (ornithiscians)[sic]. The main difference between the two hip structures is that the pubic bone of the bird-hipped dinosaurs is directed toward the rear (as it is in birds) rather than entirely to the front (as it is in mammals and reptiles).

But in most other respects, the bird-hipped dinosaurs, including such bizarre creatures as the armor-plated ankylosaurs and the horned ceratopsian dinosaurs, are even less bird-like than the lizard-hipped, bipedal dinosaurs such as the theropods. This point is rarely emphasized in popular accounts of dinosaur/bird evolution. [Emphasis mine]

As you can see, the inaccurate listing of saurischian sauropods, as ornithischians, has become an accurate listing of some actual ornithischians. Which is all well and good, however there is no asterisk, no editor’s note, no update, nothing to let their readers know about this rather spectacular error or the changes made to correct it. It is just gone as if it never happened.

Way to be intellectually honest Answers in Genesis!

Innuendo Ad Nauseam

I will not rehash all the information about the similarities between the hipbones of theropod dinosaurs and various birds, both fossil and living, you can go back and look at my previous post on Menton’s mistake for that. However I am going to take a run at his attempted insinuation (in the last sentence quoted above) that paleontologists are somehow embarrassed by the fact that ornithischian dinosaurs, with their bird-like hips, were otherwise not particularly bird-like and therefore don’t like to bring them up when talking about bird origins.

This makes sense only if you A) have a low very opinion of scientists and think they are involved in a conspiracy to hide things from the general public (which creationists do). And B) are wed to the idea that the superficial resemblance of one feature must imply a close evolutionary relationship; but who does this (aside from creationists that is)?

These two paragraphs of Menton’s article are essentially an irrelevancy, which exists solely for making this innuendo. There may have been some 19th century paleontologists who were impressed by the superficial resemblance of the pelvic bones of ornithischians to those of birds but with very few exceptions (Galton 1970), this idea has been long abandon. If this is “rarely emphasized” in popular discussions of bird evolution it is because it is only of historical interest and not relevant to the current best science on the subject.

That said, some popular works on the subject do in fact discuss it, even including discussions of the armored dinosaurs that Dr. Menton is so keen for us to consider.  For example, pulling something of my bookshelf, there is a section of Lowell Dingus & Timothy Rowe’s book The Mistaken Extinction (1998, pp.170-177) where they go on for several pages discussing the different types of ornithischians and how they are, or rather are not, similar to birds.

On the web, there is The University of California, Berkeley Museum of Paleontology’s website that talks about this on their page about ornithischians and hidden in the deep recesses of Wikipedia, where no one is likely to find them, there are multiple references to ornithischians in relation to birds. For example, both the Origins” section of Wikipedia’s entry on the evolution of birds and the entry for ornithischia talk about ornithischians and birds.

Finally, returning to the printed page, there is every creationist’s most favorite expert on bird evolution* Alan Feduccia (Professor Emeritus at the University of North Carolina), who discussed this in his book The Origin and Evolution of Birds (1999):

Very early on …dinosaurs branched into two major groups delineated by the structure of their hips: the reptile-hipped saurischians and the bird-hipped ornithischians. There has long been a strong temptation to try to derive birds from ornithischians because of this amazing but anatomically superficial resemblance of the hips. Gerard Hellmann in 1926 wrote that “the mere fact that [the pubis] was directed backward, like that of the birds, has evidentially hypnotized several scientists that they have overlooked, or tried to set aside, the many conspicuous differences between the birds and the Predentates [Ornithischia]” (148). …Ornithischians were highly specialized herbivores, too far removed from the main line of dinosaurian evolution to have given rise to any major group. Their line dead-ended with such forms as the duckbills, armored ankylosaurs, plated stegosaurs, and horned ceratopsians like Triceratops.  [Feduccia 1999, pp.51-52, Emphasis mine]

As you can see, it is all a big dark secret that evolutionists do not want getting around, so please, please, dear reader, do keep it to yourself.

This Little Piggy Went To Market…

Of course here I have once again been picking the fly poop out of the pepper, taking time to quibble over something nuanced when I should be telling you about how Dr. Menton, has dropped another huge coprolite into our collective cornflakes.

You see while I was revisiting Dr. Menton’s article I decided to take a little more time with it and in doing so I noted a few more amusing anatomical errors. The most glaring having to do with the dromaeosaurid dinosaur called Deinonychus:

Menton: While evolutionists now agree that birds are related in some way to dinosaurs, they are divided over whether birds evolved from some early shared ancestor of the dinosaurs within the archosauria (which includes alligators, pterosaurs, plesiosaurs, ichthyosaurs, and thecodonts) or directly from advanced theropod dinosaurs (bipedal meat-eating dinosaurs, such as the wellknown [sic] Tyrannosaurus rex). The latter view has gained in popularity since 1970, when John Ostrom discovered a rather “bird-like” early Cretaceous theropod dinosaur called Deinonychus.

An adult Deinonychus measured about 12 feet (3.5 m) long, weighed over 150 pounds (68 kg), and was about 5 feet (1.5 m) tall standing on its two hind legs. Like other theropods (which means “beast foot”), Deinonychus had forelimbs much smaller than its hind limbs, with hands bearing three fingers and feet bearing three toes. The most distinctive feature of Deinonychus (which means “terrible claw”) is a large curved talon on its middle toe. [Emphasis mine]

Without getting distracted with the false equivalency Dr. Menton makes between the minority, “(unknown) archosaur origin” camp and the majority “theropod origin” camp*, his description here of the feet of Deinonychus is wrong on at least two counts.

First, Deinonychus like most theropods (and birds) had four toes, not three as Dr. Menton states. In Deinonychus‘ case, three robust forward facing toes and one somewhat reduced backward facing toe—the fifth digit is reduced to a splint bone (Ostrom 1969, p.124).


dino-bird-feet-compComparative illustration composed by Emily Willoughby (used with permission).


Second, the large curved claw that gives Deinonychus its name is on the anatomically second toe, not the third, which is the “middle” toe in tetrapods. Nor is it on the “middle toe” if we ignore the existence of Deinonychus‘ reduced first toe (hallux) and pretend it only had three forward facing toes. Even in this case the enlarged toe claws of Deinonychus are on the inside toes of its feet, not the middle toes.


Deinonychus feetThe photograph on the left is by Denver W. Fowler and was taken of a specimen on display at Museum or the Rockies, Bozeman, Montana (used with permission, for more on Deinonychus see Fowler et al., 2011). The drawing on the right is from the Yale Peabody Museum website.


So no matter how you count these little piggies, whether from a technical anatomical perspective, or just informally, Dr. Menton, creationist anatomist extraordinaire, is mistaken once again.     

This leads to a couple of questions. If Dr. Menton does not know such basic facts as, what types of dinosaurs are ornithischians or saurischians, how many toes theropod dinosaurs had, or which toes are which, why should anyone take his opinions on the more complex question of the evolutionary relationship between theropods and birds seriously?  

And why would anyone put their trust in Answers in Genesis as a reliable source of information if they apparently willing to cover up this sort of ignorance, which had been on their site, misinforming their readers for years, by quietly changing things without any sort of notice or acknowledgement?

I leave the answers to the reader.

It Is Thus Because It Pleased God To Make It Thus

There is much more in Menton’s article that needs to be addressed and I am going to separate those into a second post. However, there is one last statement by Menton to attend to here. You see just about right in the middle of his article Menton dropped an anti-science bomb that seems to render the rest of his arguments effectively meaningless.   

Menton: What would it prove if features common to one type of animal were found on another? Nothing. Simply put, God uses various designs with various creatures. Take the platypus, for example—a mosaic. It has several design features that are shared with other animals, and yet it is completely distinct. So if a dinosaur (or mammal) is ever found with feathers, it would call into question our human criteria for classification, not biblical veracity. What’s needed to support evolution is not an unusual mosaic of complete traits, but a trait in transition, such as a “scale-feather,” what creationist biologists would call a “sceather.” [Emphasis mine]

I’ll save my barbs about the platypus, feathered mammals and “sceathers”, for part two, because the main point here (which makes those things and pretty much everything else in his article irrelevant) is Menton’s offhanded dismissal of the significance such things as feathered dinosaurs. His statement essentially boils down to an argument that such things as feathered dinosaurs, fish with feet or “ape-men”—you know, transitional or intermediate forms—are merely the creations of a whimsical deity who chose to arbitrarily to mix and match characteristics of different groups of organisms and are therefore irrelevant. After all God can make anything, in anyway he chooses and for any reason he see fit to do so.

This is also known as “using the miracle card” or an appeal to magic. Dr. Menton is of course free to do this; however, in doing so he abandons all pretence of doing science, or even attempting to make rational arguments.   

Why does he bother arguing about different anatomical or physiological features of dinosaurs and birds? Why does he bother to fold, spindle, or mutilate the facts about these things and to misquote scientists regarding them (more on this in part two), if in the end you just going to say, “regardless of the facts, it is the way it is because God did it that way, period”?

It would save everyone a lot of time if he just said this sort of thing up front, so that rational people, who actually accept science and who care about the facts, will know that his claims can be dismissed without further consideration.

So, those are the major things I wanted to address first—and where some of you might want to stop and get off—however, for those of you who are gluttons for punishment, there is, as I said, much more in Dr. Menton’s article that is of false and or misleading nature to be addressed. I will examine those in a separate post.

Fairly warned ye be!

Footnote

*Alan Feduccia is part of a shrinking minority of scientists who deny the evidence that birds evolved from theropod dinosaurs in favor of an older hypothesis that birds evolved from an earlier unknown group of archosaurs (a group that includes crocodilians, pterosaurs, dinosaurs and smattering of other extinct types). Their frequent and often strident attacks on the evidence that birds evolved from theropod dinosaurs make Feduccia, and others like him (the late Larry Martin for example), the go to scientists for creationists to quote on the subject of bird evolution. Creationists use their attacks on the mainstream view of bird evolution to try to cast doubt on whether birds evolved at all.

See:

References

Dingus, Lowell & Rowe, Timothy (1998) The Mistaken Extinction, W. H. Freeman and Company, New York, NY

Fedducia, Alan (1999) The Origin and Evolution of Birds (2nd Edition), Yale University Press, New Haven, CT  

Fowler DW, Freedman EA, Scannella JB, Kambic RE (2011) “The Predatory Ecology of Deinonychus and the Origin of Flapping in Birds“, PLoS ONE 6(12): e28964

Galton, Peter M. (1970) “Ornithischian Dinosaurs and the Origin of Birds”, Evolution, 24(2): 448-462

Ostrom, John H. (1969) “Osteology of Deinonychus antirrhopus, an Unusual Theropod from the Lower Cretaceous of Montana”, Peabody Museum of Natural History Bulletin, 30:1-165

The evolution of feathers in about 3 and a half minutes

By Carl Zimmer:

[Hat tip to Brian Switek.]

Answering feedback on Haeckel’s embryo drawings

A commenter named Brad, who is apparently a creationist, left a comment to one of my recent posts.  In that post, “Creationist foists “fraudulent” embryo picture on his readers“, I talked about how creationist Brian Thomas ironically used a biologically inaccurate picture of a human embryo to illustrate his article in which he denies the evidence for evolution from developmental biology and implies that all such evidence is based on the supposedly fraudulent embryo drawings 19th century biologist Ernst Haeckel.

Not wanting it to be neglected in the comments section, I have moved my response to Brad up to a full post.

Brad: Wow, evolution is like magic. It turns gills into ears, tonsils, and glands (and part of the larynx).

There is no magic involved in evolution, you’re thinking of creationism, the very heart of which is the claim that living things are the miraculous creations of a supernatural being.

Brad: Calculate the odds…

Since by all available evidence it did in fact happen, the odds are 100%.

Brad: Granted, it was a bad choice with the stock photo; however, that’s possibly an oversight vs. the intentional use of known fraudulent drawings for decades in school textbooks.

I would suggest that it was an “oversight” brought on by ignorance of the subject and a lack of curiosity to even check. As for the recycling of Haeckel’s embryo illustrations in textbooks (as illustrations of evidence rather than as a historical reference) this due to the regrettable and all too common laziness on the part of textbook publishers who often recycle not just images but even language as well. See: Stephen Jay Gould’s essay “The Case of the Creeping Fox Terrier Clone” (Gould 1991).

I agree that some* of Haeckel’s drawings exaggerated overall similarity of the embryos they depict and that more accurate illustrations should be used. However, I am unaware of any fundamental anatomical inventions in the illustrations that if corrected would affect the evidence from comparative embryology for evolution.

So, please explain in your own words exactly what anatomical details were altered in Haeckel’s drawings that created evidence for evolution where none exists in actual vertebrate embryos.

Remember, specific anatomical details and in your own words. I don’t want quotes of vague generalities from other people. You’ll note that in my post on pharyngeal clefts at no point did simply I quote some scientists opinion that the pharyngeal apparatus of amniote embryos are homologous to the pharyngeal apparatus of “fish”. Instead I pointed to the anatomical and genetic evidence for this.

If you are going to argue against this, then you are going to have to do likewise.  And if you want to present an alternative scientific explanation you are going to have to present something that is logical, coherent, makes reference to the empirical evidence at hand and does not rely on untestable miracles or divine fiat.

Brad: O’Rahilly and Müller stated that ‘the pharyngeal clefts of vertebrate embryos … are neither gills nor slits’.1

I don’t have this reference handy and I don’t know when I’ll get a chance to get to my local university’s science library (whose website says they have it) I was able to find a later edition on Amazon with a free preview which allowed me to get what seems like the relevant section.  If the older edition has any important differences please let me know (assuming you have the book and didn’t just cut and past the quote from a creationist and/or anti-abortion website).

Here is the the section which seem to contain Brad’s quote with the part Brad quoted in red:

Recapitulation, the So-Called Biogenetic Law.

The theory that successive stages of individual development (ontogeny) correspond with (“recapitulate”) successive adult ancestors in the line of evolutionary descent (phylogeny) became popular in the nineteenth century as the so-called biogenetic law. This theory of recapitulation, however, has had a “regrettable influence on the progress of embryology” (G. de Beer). The work of Carl Ernst von Baer in 1828 was much closer to the mark. According to the “laws” of von Baer, general characters (e.g., brain, notochord) appear in development earlier than special characters (e.g., limbs, hair). Furthermore, during its development an animal departs more and more from the form of other animals. Indeed, the early stages in the development of an animal are not like the adult stages of other forms but resemble only the early stages of those animals. The pharyngeal clefts of vertebrate embryos, for example, are neither gills nor slits. Although a fish elaborates this region into gill slits, in reptiles, birds, and mammals it is converted into such structures as the tonsils and the thymus. According to the hourglass model of evolutionary development, a conserved pattern of developmental gene expression is linked with considerable resemblance among embryos of different species at a constricted phase, whereas divergence is found earlier and later. Morphological evidence for such a phase, however, is unconvincing (Richardson et al., 1997). (O’Rahilly & Müller 2001, p. 16)

Although there are issues I could take with their description of recapitulation as necessarily being about a strict correspondence between embryos and the adult forms of ancestors or with the short shrift they give the concept of the phylotypic stage (at least in this paragraph), however those are really nuanced points that are not necessary to get into here.

One point I will quibble with regards the presence of slits in certain amniote embryos.

Everything I have seen on the subject indicates that the pharyngeal clefts of some “reptiles” and birds do normally perforate during development and are therefore technically “slits” for a short time before they re-close. This also sometimes occurs in mammals, including humans, though it is not a normal condition. (see my earlier article for links). Also they’ve left out any reference to the larvae of amphibians some of which do develop functional gill slits.

Beyond that, they are absolutely correct, the pharyngeal apparatus of amniotes never function as gills and as I said in one of my earlier posts, I don’t know of any biologist who has ever claimed that they do, save one, the creationist Louis Agassiz.

The Great Satan, Ernst Haeckel, stated in no uncertain terms in his writings that these structures never function as respiratory organs in amniote embryos.

It is not required that the pharyngeal apparatus of amniote embryo function as gills for them to be evidence—not absolute, stand alone proof, but evidence—of their ancestors aquatic nature any more than it is necessary for the hind limb buds of whale embryos to function as working legs for them to be evidence that their ancestors once walked on land.

Brad: Blechschmidt is more forceful, concluding that ‘the so-called basic law of biogenetics is wrong.

The late Erich Blechschmidt (1904-1992) was a scientific outlier (as are some of his followers, i.e. Brian Freeman). That is his views were not representative of developmental biologists as a whole. Creationists love to quote Blechschmidt and other outliers such as Alan Feduccia (who denies that birds are descended from dinosaurs) and Charles Oxnard (who denies that australopithecines are human ancestors) in an attempt to make it seem as if they are tapping into some real controversy amongst scientists. In reality they are just quoting people who are only slightly less on the fringe of science than themselves.

You can find someone with an advanced degree that will say just about anything. For example there is PhD astronomer (and creationist) Gerardus Bouw who argues that the Earth is the center of the solar system.

In this case Blechschmidt (and Freeman) seem to be the source for creationists absurd argument that pharyngeal clefts are merely “flexion folds” caused by the bending of the embryonic neck (Freeman 2001).

As for the biogenetic law, no one is arguing for that. If you read the article you were commenting under you would have seen that I quoted Michael Richardson (a critic of Haeckel) as saying that there are studies which support the recapitulation of individual character transformations, just not whole ancestral stages (Richardson & Keuck 2002, p. 522)

Brad: ” ‘No buts or ifs can mitigate this fact.’ He adds that the gill stage myth is ‘not even a tiny bit correct or correct in a different form…It is totally wrong’. 2 This view is shared by many mainstream embryologists.

No, it is not.

Although among the strongest opponents to Haeckel in recent years, and favourably differing from him by a paramount respect for detail, Blechschmidt resembled Haeckel in several respects: they both were intrepid and very persuasive defenders of their views, they were both artists at heart – witness Haeckel’s illustrations and Blechschmidt’s giantsized models of human embryos – and, most importantly in the present context, they both stuck to some outdated ideas not shared by the majority of contemporaneous biologists: Haeckel remained Lamarckist, defending the inheritance of acquired characters throughout his life, and Blechschmidt strove to maintain the special status of Man by condemning any embryological interpretation or terminology suggesting his descent from other vertebrates. (Sander 2002, p. 531, emphasis mine)

So Blechschmidt apparently had issues with accepting the evolutionary development of humans from other animals. As I said an outlier with an extreme minority view.

Brad: in the end, this is probably an argument evolutionists should give up on.

You’ll understand, I hope, that this evolutionist will not be taking advice on what is or is not valid evidence from a creationist.

Brad: But keep right on with it if you insist, it just makes dogmatic evolutionists sound nuts.

Only to those too ignorant to know better and/or too intellectually lazy to look up the evidence for themselves.

*Note: I am thinking primarily of the first stage shown in the comparative embryo illustration in the 3rd edition of his Anthropogenie (1874)

References

Freeman, Brian (2001) “The Myth of the “Biogenetic Law””, The American Biology Teacher 63(2):84

Gould, Stephen Jay (1991) “The Case of the Creeping Fox Terrier Clone”, in: Bully for Brontosaurus: Reflections in Natural History,  W.W. Norton & Co., pp. 155-167

O’Rahilly, Ronan & Müller, Fabiola (2001) Human Embryology & Teratology, 3rd Edition, Wiley-Liss

Richardson, Michael & Keuck, Gerhard (2002) “Haeckel’s ABC of evolution and development“, Biological Reviews, 77: 495-528

Sander, Klaus (2002) “Ernst Haeckel’s ontogenetic recapitulation: irritation and incentive from 1866 to our time”, Annals of Anatomy 184:523-533

Fuzzy thinking about fuzzy dinosaurs

A visual approximation.

Casey Luskin, the Discoveryless Institute’s resident attack chihuahua, is on a roll. This time he’s gone off on a tangent about a recent find of yet another dinosaur fossil with evidence of protofeathers, Sciurumimus albersdoerferi and dinosaur evolution in general.

Luskin: The media that loyally serve Big Science are at it again, overstating the finds of a scientific paper to promote an evolutionary icon. This time, the icon is feathered dinosaurs, representing the purported ancestral relationship between dinos and birds. (Luskin 2012)

Ah, if only. If only Mr. Luskin’s conspiratorial fantasy were true and the media was that on the ball. The fact of the matter is that defenders of science education like me often cringe at the mischaracterizations and overstatements that come out of the popular media regarding evolution. I am constantly shaking my head and yelling at the TV or radio “no, that’s not what that means at all”, or words to that effect.

I wish I had a nickel (because being underemployed I could really use the money) for every time a silly reporter, while talking about some fossil discovery, described it as “overthrowing everything we thought we knew about the evolution of X”.

That is absolute bollocks, 99% of the time.

Read on»