ICR blocked me on Facebook


So, the Institute for Creation Research put up a link on their Facebook page to one of their latest Acts & Facts articles on the whole Ernst Haeckel/vertebrate embryos thing and since the sort of stuff creationists write about this subject is a pet peeve of mine (as readers of this blog will no doubt have gathered) I decided to post a quick comment on the following quote from the article:

Guliuzza: Shouldn’t students be skeptical when they’re told that evolutionists can simply look at folds in embryos and see gill slits? The truth is that these are only folds of tissue in the pharynx region of vertebrates during the pharyngula stage of development. For mammals, birds, and reptiles, they never develop into a structure that is in any way like fish gills.

I wrote that this statement was not true as would be known to anyone who had cracked an embryology textbook and asked if Dr. Guliuzza (the author of the article) was therefore incompetent in this area or if he was being deliberately misleading. Further I provided a link to my blog post on the subject of “gill slits” so that anyone interested could look at the evidence for themselves.

I also corrected one of their other commenters on what Thomas Huxley and Charles Lyell’s professions and religious perspectives were. I also noted to the commenter that all science, not just evolutionary biology, leaves God and other supernatural agents out of its explanations.

I used no harsh language, I did not call anyone any names and I engaged in no mockery (unless you count my pointed question about Guliuzza competency/honesty) and yet the end result was that my link and all my comments have been deleted and I am apparently now blocked from commenting on ICR’s FB page.

I’ll leave the reader to decide what this says about ICR and the robustness of their scholarship.


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:


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


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:


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.

And now a little poorly concealed bragging



Last weekend while I was awaiting delivery of my copy of Cambridge University historian of science Nick Hopwood‘s new book Haeckel’s Embryos: Images, Evolution, and Fraud (2015) on 19th century biologist Ernst Haeckel and his (in)famous embryo illustrations, (which I have written about a few times here an PCWP and elsewhere), I got a Facebook notification that I had been “tagged” in a post by my friend (in real life, not just Facebook) and colleague Dr. Nick Matzke. The somewhat cryptic post said the following:

Hey look who’s in the acknowledgements – Troy Britain

Attached to this comment was the following picture:


Thereafter the comments conversation between Nick M. and I went like this:

Me: Wait, wait, wait, this isn’t Hopwood’s new book is it (my copy is in route)?!

NickYep it is!!

Me: Holy crap!

Nick: Immortality!

Apparently Professor Hopwood was kind enough to mention me (and Nick Matzke as well) in the acknowledgements section of his new book (page 304).

 The relevant section reads as follows:

For crucial pieces of advice, I thank Thomas Brandstetter, Troy Britain, Solveig Jülich, Ron Ladouceur, Nick Matzke, Signe Nipper Nielsen, Ron Numbers, Jesse Olszynko-Gryn, and Constance Sommerey…

Quite an honor! All the more given the company of people like Nick Matzke, Ron Numbers and the rest.

Thank you Prof. Hopwood, you are too kind! And thank you for writing this book! It needed to be done and I look forward to reading it (or rather the rest of it, I’m up to chap. 3 already)!


Memories of Peking Man at the American Museum of Natural History

Jon and I outside The Academy of Natural Sciences in Philadelphia of Drexel University, PA (photo by Don Frack).

While looking through some old photographs, for something else I am working on, I came across some snap shots I took back in 1998 when my friend Don Frack and myself flew back to the East coast to attend the DinoFest 98 symposium (a combination dinosaur fossil exhibition and gathering of dinosaur paleontologists) in Philadelphia, PA.

We figured that to make going really worth our while (and our money), we would make a couple of side trips. We planned to arrive a couple days early, rent a car and drive up to New York for a day and go to the American Museum of Natural History (we were joined on this leg of our journey by our friend Jonathan Woolf who we knew from back in the CompuServe forum CvE debates). We would then

A Triceratops skull and myself at The Academy of Natural Sciences, in Philadelphia, PA (photo by Jon Wolff).

A Triceratops skull and myself at The Academy of Natural Sciences, in Philadelphia, PA (photo by Jon Woolf).

return to Philadelphia and attend the three day symposium, after which Don and I would drive down to Washington D.C., go to the Smithsonian National Museum of Natural History and fly home from there.

It was at once a fun, fascinating and frustrating trip, which I won’t get too much into now. Let’s just say the both of us a life-long Californians experienced a combination of a bit of culture and geography shock.

Anyway, since we were going to go to the American Museum, Don thought he might contact a couple of the scientists who worked there to see if we could go behind the scenes and get a closer look at some of the material in their collection. In this case material that is of particular interest to those of us involved in the creation/evolution debate, namely their casts of the original “Peking Man” (a.k.a. Sinanthropus pekinensis but now recognized as Homo erectus) material. The fossils represented a number of individual H. erectus‘, unearthed in China at a site known as Zhoukoudian (or Choukoutien) near Beijing in the late 1920’s and early 30’s.

Read on»

Answering Creationist Questions

Someone named Stephen has asked some questions on my “creationist questions” page and I am moving my response up to the main page.

Hello Stephen!

Just to get a couple points of order out of the way I want to note that you asked three questions at once and only one (#3) touches on evolutionary biology, violating my question guidelines in multiple ways right off the bat. However, I said might grant some leeway and I will in this case.

Stephen: First, to clarify, I am a college student, almost through with my history degree (as a major), I have a minor in geology, and I have taken enough courses to almost have minors in philosophy and anthropology (just establishing that I am not an uneducated internet troll…. at least not completely). This does not make me an authority on the debate between evolution and creationism, but I have studied enough to be fairly well versed in the arguments that each side uses.

OK, good to know; as it would mean that there is no reason you should be making any glaring errors in those areas, yes?

Stephen: I was home-schooled by choice and was taught evolution and creation equally…

You were taught about a mature and productive scientific field and the relatively brief creation story from the Hebrew scriptures (backed up, no doubt, with the pseudoscience, misrepresentations and misinformation of “creation science”), “equally”?

You should understand that from my perspective that doesn’t make a lot of sense.

Stephen: I studied the sides and decided to pick the side that, I believe, has the least number of holes in its arguments. I decided to become a creationist, but I still see both sides and am willing to keep my mind open to all possibilities.

Well then, my question would be what are some of the supposed “holes” in evolutionary theory? Please do not tell me they are of the sort usually put forward by “creation scientists”, I have a library full of those bogus arguments.

Again, from my perspective creationism is collection of long refuted empirical claims (young Earth, Flood geology) backed by a premise (“God did it”) that is fundamentally untestable and therefore scientifically useless.  

Stephen: Question 1: How do you define science (yes, I am talking about the AIG argument between “testable/repeatable science” and “historical/perceived science”)? I do mean you specifically, as different words mean different things to different people, and “standard definitions” do not always fully encapsulate this idea.

In the context you seem to be asking (that of Answers in Genesis’ idiosyncratic redefinition of science), I would say that science is a process wherein people derive coherent explanations about the state of the natural world which are testable by further, intersubjective, observations of the natural world. This holds regardless of whether the particular phenomenon under examination is something that occurred in the past or is currently ongoing.

In science, one does not have to be able to repeat the occurrence of something in order to explain it. What is necessary is that the observations that are made to test the explanation be repeatable by anyone who makes the effort, i.e. not subjective revelations knowable only to an individual or an elect few.

As with forensic science used against criminals, one need not repeat the crime in order to make observations (of finger prints, DNA, etc.) to build a case as to who the most likely perpetrator is.

The same is true when one is trying to explain the current state of nature be it biological, geological or astronomical. We do not need to repeat, in full, the processes that lead to the current state of affairs in order to piece together a case against the most likely “perpetrator”.

Of course, in practice, there is more to it than that but I am not writing a book on the philosophy of science.

Professional creationists want to muddy the waters on this because their explanations either have failed to hold up against observations of the natural world, or are simply not testable by such observations. In other words, their ideas are either failed science or non-science and so they try to tear down good science in an attempt to mislead people into believing that their ideas have merit.    

Stephen: Question 2: Why do scientific laws exist: gravity, thermodynamics, etc. if no one created them (yes it does seem like a silly question, but believe it or not, I have found this question to be helpful)?

This is a question about cosmology and is essentially asking why the universe is the way it is. My answer is, I do not know. Cosmologist are working on such questions and they may or may not be able to answer some or all of them someday, however I see no reason to assume that if they do find answers to them that they will include the idea that the universe was “created” by a conscious being of some sort.

Any explanations that cosmologists do come up with will have to be testable by observations of the natural world in order to be scientific. “God did it” does not meet that criterion.

Stephen: Question 3: How do you believe that things such as a conscience, idea of self-awareness, and the ability to fully reason came to be? Yes, this is a philosophical question, because philosophy is the first “science” and was the root of all the other disciplines.

I don’t know if the ability to “fully reason” actually exists and I would quibble with you that these are necessarily philosophical questions. I would say that the evidence suggests that these things are evolved characteristics as we see them in a continuum in the animal world with humans merely being at one end of the spectrum.

Stephen: In addition, evolution influences much more than biology, geology, and physics (to name a few of the traditional sciences) in its scope, and all aspects of the theory need to be considered.

I disagree. Biology, geology and (to a lesser degree) physics influence evolutionary theory but not the other way round. Evolutionary theory had to be consistent with the facts of biology (obviously) but also geology and physics in order to be considered successful. Theories of geology (plate tectonics etc.) or physics (relativity etc.) do not need to factor in evolutionary theory but rather stand or fall based on observations from those fields.

If inconsistencies between evolutionary theory and say, plate tectonics, were discovered, then those would have to be worked out, but physical geologists who are trying to solve geological problems do not sit around worrying about how their findings might affect those of biologists. They find what they find and it is up to the biologists to figure out whether their own theories can be made to fit with the new data or must to be scrapped in favor of new ones.

What you are talking about reflects the conspiracy theory thinking of creationists, wherein all of modern science is some sort of evolutionist plot to discredit the Biblical account of creation, it isn’t.

The actual problem is that the facts of nature, biological, geological and physical, simply are not consistent with creationism and creationists have adopted this conspiracy idea as a way to avoid facing that fact.

Stephen: Especially since the idea of “origins” is one of the three fundamental questions of philosophy (IE: Where did I come from? Why am I here? Where am I going?).

“Where did I come from?” is an empirical question answered by science; proximally by reproductive biology and evolutionary theory more distally by astronomical and cosmological theories. You would have to be more specific to get answers that are more specific.

“Why am I here?”—assuming it is not merely a rephrasing of the previous question—is a question that assumes something not in evidence, that there is some externally imposed purpose to our existence. It could be that there is no “why” and therefore the question is incoherent.

“Where am I going?”, again this assumes that you are going anywhere. Barring evidence that anyone is going anywhere this question is also incoherent.

Stephen: By the way, I have heard your comparison of “playing chess with pigeons” before (in relation to evolutionists). Is that saying original (to you) or did you get it from elsewhere? If so, where?

The answer to that may be found in the tab at the top of my blog titled “Playing Chess with Pigeons?“. It is taken from something first written by Scott Weitzenhoffer in reference to creationists; so if you have seen it being used in any other way it was pilfered directly or indirectly from him.


From the Inbox: Did Stephen Jay Gould fabricate evidence of Louis Agassiz’s racism?

This one is from an e-mail sent to me via my neglected website over at commondescent.net regarding a page I have there that is mostly a bunch of quotes from Charles Darwin on the subject of race and slavery. The point of the page (that I originally created over a decade ago) was to counterbalance creationists’ never-ending demonization of Darwin as some sort of rabid racist—who was somehow responsible for racism and genocide—by the use of selective quotation of his writings (for example, Bergman 1997).

Anyway, someone going by “ML” writes:

ML: Why do Atheists get so upset when a Theist speaks about Darwin being Racist?

Atheism or theism does not enter into this, at least not inherently. I would think that anyone, theist or atheist, who interested in science and history would be upset by how professional creationists use invalid reasoning and false or misleading historical narratives to attack both evolutionary theory and historical figures involved in its development.

In the case of the claims that Darwin was somehow particularly racist, creationists are attempting to poison the well against evolution by claiming that the founder of evolutionary biology had some objectionable and/or erroneous views. They are arguing, in essence, that since Darwin was a racist evolutionary theory is suspect.  This is form of an ad hominem fallacy*.

Whether or not Darwin was a racist is completely irrelevant to the question of evolutionary theory’s validity. It stands or falls on its own merits regardless of what Darwin thought—for example, Isaac Newton believed in alchemy but this in and of itself does nothing to cast doubt on his laws of motion.

Logical fallacies aside the creationists’ treatment of Darwin on this subject is also simplistic and disingenuous in both the way they exaggerate Darwin’s supposed racism relative to his peers—well-to-do white men of the early to mid-nineteenth century—and in how they conveniently ignore clear cases of racism in their own camp (more on this shortly).  

[*Side note: creationists typically go further and attempt to argue that evolutionary theory itself is inherently racist or must logically lead to racism. That however that topic is for another time.]

ML: Racism is simply thinking you are superior to another race. One does not have to wish another race harm to be a Racist.

Why don’t you stop confusing the issue and trying to downplay the reality that Darwin was in fact racist.  He thought that whites were superior in many ways to blacks. That is RACISM.

I am not attempting to downplay the reality of anything. I am trying to be both factually and historically accurate. My personal opinion is that from a modern perspective Darwin probably was somewhat racist; however this is judgment that has to be inferred from a number of conflicting things he wrote on the subject. Some things he wrote—especially if they are taken out context of both history and his larger writings—seem to be racist in nature. However, he also wrote many things about race that were very egalitarian particularly in comparison with views of many of his contemporaries.

Given this, I think it is unfair and dishonest to single Darwin out for special criticism in this regard, especially if those doing so leave out evidence of more clear-cut racism on the part of their own intellectual predecessors.

ML: One also does not have to believe slavery is right or wrong to be a Racist.

That is true, one would have to look at the reasons an individual gives for why they condemned slavery. Some opposed slavery on the basis that the institution of slavery had negative effects on slave owners and white society in general. Others did so out of a concern for those enslaved (and of course many opposed slavery for both reasons).

I think it is fair to say that while someone who opposed slavery largely out of concern for those enslaved might still be a racist, they are probably not as racist as someone who either opposed it primarily out of concern for slaver owners or who did not oppose it at all (even arguing in its favor).

ML: Your article is so biased its pathetic.

Insults, that’s nice. You are going to have to do better than that ML. However, I will admit that the page could probably do with some expansion and updating.

ML: Quoting Louis Agassiz in a letter to his mother (1846), quoted in Gould, Stephen The Mismeasure of Man (1981) p. 44-45,

Stephen Gould IS AN EVOLUTIONARY BIOLOGIST AND AN ATHEIST!! What a source you got there!

A Letter that no one knows it really existed because it just so happens the only person who ever heard of it happens to be an ATHEIST.

Here we have yet another ad hominem fallacy, i.e., the source is an evolutionary biologist and an atheist, therefore it cannot be trusted.

Sorry but the fact that someone has delusional beliefs regarding the relative honesty of either evolutionary biologists (a category that includes a number of Christians btw) or atheists, does not constitute Prima facie evidence that there is any reason to doubt the veracity of the quote as given by Gould.

What’s more, while many—including myself—have taken issue with Gould on any number of subjects, I am unaware of any serious critic ever having suggested that Gould fabricated evidence whole cloth to support his views.  So even on an individual level, there is no reason to take seriously the suggestion that Gould was in the habit of perpetrating fraud.

Of course, anyone who knows me knows that I cannot leave it at that (let’s see, where did I leave my BFG 9000).

These accusations of fraud ML is making regard a quote from the 19th century paleontologist Louis Agassiz that I gave as an example of unambiguous racism on the part of one of Darwin’s creationist contemporaries. Here is the quote in question, which comes from a letter Agassiz wrote to his mother:

It was in Philadelphia that I first found myself in prolonged contact with Negroes; all the domestics in my hotel were men of color. I can scarcely express to you the painful impression that I received, especially since the feeling that they inspired in me is contrary to all our ideas about the confraternity of the human type (genre) and the unique origin of our species. But truth before all. Nevertheless, I experienced pity at the sight of this degraded and degenerate race, and their lot inspired compassion in me in thinking that they were really men. Nonetheless, it is impossible for me to repress the feeling that they are not of the same blood as us. In seeing their black faces with their thick lips and grimacing teeth, the wool on their head, their bent knees, their elongated hands, I could not take my eyes off their face in order to tell them to stay far away. And when they advanced that hideous hand towards my plate in order to serve me, I wished I were able to depart in order to eat a piece of bread elsewhere, rather than dine with such service. What unhappiness for the white race ―to have tied their existence so closely with that of Negroes in certain countries! God preserve us from such a contact.” (Agassiz, 1846, Emphasis mine)

ML states that no one knows if the letter Gould claims to be quoting from even exists, implying that Gould may have made this quote up. Is there anyway for us to discern whether or not this might be the case, or are we forever lost in perpetual doubt?

Well we could start by seeing what Gould says about the source of this quote:

Agassiz had never seen a black person in Europe. When he first met blacks as servants at his Philadelphia hotel in 1846, he experienced a pronounced visceral revulsion. This jarring experience, coupled with his sexual fears about miscegenation, apparently established his conviction that blacks are a separate species. In a remarkably candid passage, he wrote to his mother from America: […quote given above – TB…] The standard Life and Letters, compiled by Agassiz wife, omits these lines in presenting an expurgated version of this famous letter. Other historians have paraphrased them or passed them by. I recovered this passage from the original manuscript in Harvard’s Houghton Library and have translated it, verbatim, for the first time so far as I know. (Gould 1981, p. 44-45)

Uh oh, “other historians”, “original manuscripts” at Harvard; it is starting to look bad for ML’s fraud hypothesis.

OK, let’s take a look at what historian Edward Lurie’s biography of Agassiz might contain:

After observing Negroes for the first time during a visit to Philadelphia late in 1846, Agassiz confided to his mother:

I hardly dare to tell you the painful impression I received, so much are the feelings they [Negroes] gave me contrary to all our ideas of the brotherhood of man and unique origin of our species. But truth before all. The more pity I felt at the sight of this degraded and degenerate race, the more . . . impossible it becomes for me to repress the feeling that they are not of the same blood as we are. (Lurie 1960, pp. 256-257)

While not identical, it seems clear that this quote, by Lurie given in 1960, is from the same source as Gould’s twenty-one years later.

Lurie give as a source as: “Agassiz to Rose Agassiz, December 2, 1846, Agassiz Papers, Houghton Library”, which means that both he and Gould claim their source is an 1846 letter from Agassiz to his mother.

Now at this point I figured I would have to stop and argue that this was sufficient evidence to refute ML’s insinuation since I do not live in the vicinity of Harvard and so could not go there and check their collection for the letter.

However, this is the age of the internet and after some poking around I discovered that Harvard’s Houghton Library not only lists the material in their Agassiz collection they also have scans of the original documents including…

 Wait for it…

 The letter from Agassiz to his mother dated December 2 1846.

Now the scans aren’t great and the letter is in French (differing interpretations of which accounts for the minor differences between Lurie and Gould’s quotations) but they are there for anyone, ML included, to read for themselves.

I did, and despite the fact that my French is extremely limited I was able to find the passage in question starting bottom third or so of page 13 and ending on page 14 (you gotta love the interwebs).

Given this, I am sure we can expect a retraction from ML regarding this libel against Gould.


Agassiz, Louis (1846) A letter to Rose M. Agassiz, quoted in Gould, Stephen (1981) The Mismeasure of Man, W.W. Norton & Company, NY,  p. 44-45

Bergman, Jerry (1997) “Evolution and the Origins of the Biological Race Theory“, Journal of Creation, 7(2):155–168

Gould, Stephen Jay (1981) The Mismeasure of Man, W.W. Norton & Company, NY

Lurie, Edward (1960) Louis Agassiz: A life in science, Johns Hopkins University Press (1988)

Goodbye Neil…

One of my earliest memories is from the day after my fourth birthday in July of 1969. It is just flashes of my parents being very excited about something and images of a large rocket on a TV, it was, of course, the launch of Apollo 11 which carried the first humans to land on the Moon.

Yesterday we have lost the Commander of Apollo 11, Neil Armstrong (1930–2012), however as long as long as our species endures something of him should endure with us, the memory of the first person to set foot on another world.

Goodbye Commander and thank you for risking it all to take that giant leap for mankind.

[A bittersweet coincidence of sorts. I didn’t hear of Armstrong’s death until early Sunday morning because my wife and I were watching a marathon of old Star Trek shows (Enterprise/Voyager/DS9).]

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)


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

Creationist foists “fraudulent” embryo picture on his readers

I decided I am not going to bury the lead on this one. Brian Thomas of the Institute for Creation Research (ICR) just posted another in a long line of creationist screeds attacking the evidence for evolution from comparative embryology, which as usual claims that the evidence is based on fraud and pins much of the blame for it on 19th century biologist Ernst Haeckel.

I began writing a rebuttal straight away but then I happened to take a second look at the bright pink image of an embryo atop the article and it brought me to a sudden halt. So, having backed up, let me start again.

Thomas: German zoologist Ernst Haeckel is perhaps most famous for defending evolution with the argument that creatures replay their evolutionary past when developing in the womb. …In his zeal to promote evolution, Haeckel foisted faulty embryo sketches onto his readers, and the zeal of his followers has perpetuated those falsehoods for over a century. (Thomas 2012, emphasis mine)

Yeah, about that…


That’s right, yet another irony meter has been reduced to subatomic particles by a creationist.

Read on»

“Reason and creationism”

My friend and colleague (frienlleague?) Dr. Eugenie Scott gave, yet another, excellent talk titled “Reason and creationism” at the Global Atheist Convention, Melbourne, Australia (4/15/2012). Have a watch:

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