What do Haeckel's embryos signify?

Casey Luskin, Disco. 'Tute spinner, has recently relaunched a fight over whether and how textbooks use embryological drawings from Ernst Haeckel's 19th century popular works. In his two posts (excerpting from a jumbled essay he wrote for a law review), he repeatedly claims that those drawings are fraudulent. To wit:

textbooks in use today, in arguing for evolution, still use Haeckelâs fraudulent embryo drawings

That Haeckelâs drawings were fraudulent and have been used in textbooks is essentially beyond dispute

Stephen Jay Gould recognized that Haeckelâs drawings ⦠fraudulently obscured the differences between the early stages of vertebrate embryos

Haeckelâs fraud has had a non-trivial influence on both evolutionary thought and evolution education

a textbook submitted ⦠for adoption in Texas in 2003 ⦠used a slightly simplified version of Haeckelâs original fraudulent drawings

But here's the thing. The only place Casey actually presents an argument for "fraud" is in footnote 262 (from the "beyond dispute" claim above):

Even Matzke and Gross recognize that âHaeckel did exaggerate similarities in very early embryos of different species, and his figures, or derivatives of them, have appeared in a few textbooks.â Nicholas J. Matzke & Paul R. Gross, Analyzing Critical Analysis: The Fallback Antievolutionist Strategy, in NOT IN OUR CLASSROOMS: WHY INTELLIGENT DESIGN IS WRONG FOR OUR SCHOOLS 40 ( Eugenie C. Scott & Glenn Branch, eds. 2006).

The problem is, Casey is pretending that research into Haeckel's drawings stopped in 2002, with the publication of the deeply inaccurate Icons of Evolution. In fact, the most recent work on the topic would be Robert Richards' biography of Haeckel (The Tragic Sense of Life), and a paper Richards wrote based on his research for that book: "Haeckel's embryos: fraud not proven." You'd think anyone doing even a trivial search would have turned that paper up.

This is a disappointing oversight for two reasons. First, Casey is described by Disco. as a "staff attorney," and he should know that proving fraud takes more than just "exaggeration." Second, he submitted and published this piece as a piece of serious scholarship, yet failed a basic standard of research: accurately representing the current state of the field.

As Richards points out, a fair evaluation of the evidence shows "the charge against Haeckel to be logically mischievous, historically naive, and founded on highly misleading photography."

in particular, Richards observes that the drawings everyone talks about are from Haeckel's 1874 book, a popular work based on stenographic notes of a lecture series he'd presented, and illustrations used in that talk. He continued to revise the work through several subsequent editions, and the evidence is clear that he continued to update his drawings as newer and better embryological illustrations became available. As Richards explains:

The refinements were a function of more material available and better instrumentation (embryos at the earliest stages are invisible to the naked eye). Had the Science article [on which Luskin and others rely] compared Richardsonâs photos with illustrations from Haeckelâs later editions, the argument for fraud would have withered.

Richards, like other critics, also points out that modern photographs often offered as evidence of Haeckel's perfidy actually present their own misrepresentation.

several (but not all) of the photographed embryos retain the attached yolk sack and other maternal material; this exaggerates their differences from Haeckelâs images. Haeckel explicitly indicated that he pictured his specimens without yolk, allantois, and amnion. The bulge of the salamander is not part of the embryo; rather, it is the yolk sack, as is the case for the fish and the human embryos (though not for the chick and the rabbit, from which the yolk sacks have been removed).

When one corrects these discrepancies, Haeckel's drawings don't look nearly so different from modern photographs, as shown in the picture below (Richards' figure 5):

Casey, attempting to bolster the case for fraud, compares modern textbook illustrations to Haeckel's drawings, but does not show the comparison to photographs. This is a critical component of any claim that modern textbooks mislead through their illustrations. Haeckel's drawings are surely imperfect, but as Casey acknowledges, the textbook illustrations are not identical to Haeckel's work. The important question is whether the differences between the two illustrations correct the flaws in Haeckel's dated drawings. If not, one might argue that publishers are knowingly passing along Haeckel's inadvertent errors. But if their drawings correct those flaws, then no charge of fraud can be attached to the modern authors, either.

This is all by way of saying that Casey appears to be a lawyer who doesn't know the elements of proving fraud, who fails even to make a pass at demonstrating the charge he's prosecuting, and who fails to make his audience aware of exculpatory evidence. Not the best way to be.

See also Nick Matzke's and Matt Young and Paul Strode's replies to Luskin.

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Great post, Josh! Merely adds to Matt and Nick's prior observations on this. Luskin has had such a consistently low record of "scholarship" that it wouldn't surprise me to learn that, as a former geologist, Luskin would regard plate tectonics as a "theory in crisis".

By John Kwok (not verified) on 21 Jun 2010 #permalink

Perhaps it's that prosecutors only need make exculpatory evidence available to the defense, and are not obliged to themselves present it to the jury?

I just want to point out that "my" reply to Mr. Luskin's is really that of my colleague and coauthor, Paul Strode.

Also, you have the links reversed in the last line.

a paper Richards wrote based on his research for that book: "Haeckel's embryos: fraud not proven." You'd think anyone doing even a trivial search would have turned that paper up.

Oh, come on. One would have to google "Haeckel", "embryos" and "fraud" and you'd have to be an Einstein-level genious to think of linking those three together when you're researching Haeckel's fraudlent embryo drawings. As if that's not hard enough to conceive of, Google gives about 45,000 results and one would have to have bull-headed perseverence and indomitable energy to skim down that list all the way down to the second item to get that paper. I think that is clearly asking too much of our Casey.

By Mike from Ottawa (not verified) on 21 Jun 2010 #permalink

Rosenau 2010: "The important question is whether the differences between the two illustrations correct the flaws in Haeckel's dated drawings."

Rosenau 2007: "He fudged the details to make the whole thing look more convincing", "You'll note that, despite West's claim that this is "a version of Haeckel's drawings," they are actually quite different in their details. These are clearly redrawn photographs of actual embryos, and as such do not bear the taint of any errors Haeckel made"

So, three years ago you provided an answer to your question.
You seemed to be able to spot the significant details and You thought everyone could see them ("You'll note"). I can see that some embryos (in Raven&Johnson 2002) are coloured copies of Haeckel's and some are new. And that is fine with me because those drawings have not been fraudulent in the first place.

Matt Young: Apologies. I fixed the links and the link text.

For the record, I think that plate tectonics is one of the most well-supported theories in modern science. I'm a huge fan of plate tectonics.

In any case, Josh's backtracking is rich. Today an ID-friendly reporter asked me if I had ever responded to this page. I said I had not because I had never seen the page before today, and I don't think I ever responded to that page because I don't respond generally to attacks that don't make good arguments.

Mr. Rosenau tries distinguish between "exaggerating" the evidence and fraud. I see no distinction. If you are deliberately exaggerating the data, then how is that not fraud? This is a distinction without a difference.

In any case, my original article cited numerous sources that acknowledged Haeckel's fraud that goes far beyond Matzke's admission that Haeckel "exaggerated" the data. One example was Stephen Jay Gould, who called the drawings "fraudulent." Another quote from the leading embryology authority Michael Richardson stated about Haeckel's embryos that â[i]t looks like itâs turning out to be one of the most famous fakes in biology." Mr. Rosenau somehow thinks all that is irrelevant.

Instead, he keeps citing Richards who defends Haeckel's ideas. That's fine but I cited multiple sources--Gould and one of the top embryologists in the world, Michael Richardson (different than Richards), noting that Haeckel's drawings were fraudulent. Perhaps these authorities disagree. That doesn't make me wrong.

The other guy, Richards, apparently says that later drawings of Haeckel were not fraudulent. If that's true, it's irrelevant. The problem here is that it is Haeckel's inaccurate versions which are THE ONES published in the textbooks. That's great if Haeckel later improved his drawings, but the real issue: Haeckel's bad versions are being promoted to students.

Mr. Rosenau seems to want to change the subject rather than deal with the real problem--which is the fact that inaccurate drawings are being promoted to students. He writes: "if their drawings correct those flaws, then no charge of fraud can be attached to the modern authors, either." The problem is that the modern authors didn't correct all the problems. And I did provide documentation of this at:


The examples I showed in my article used Haeckel's drawings, and were essentially identical to Haeckel--if not worse. Mr. Rosenau writes:

"Casey, attempting to bolster the case for fraud, compares modern textbook illustrations to Haeckel's drawings, but does not show the comparison to photographs."

Well, Mr. Rosenau compares Haeckel's drawings to the photographs on his website, and they look extremely different to me. So I think Rosenau has proven my point correct. But our opinions are less important than those of authorities like Richardson, who clearly feel Haeckel committed fraud.

Thanks and I hope this helps.



Casey: You claim no distinction between "fraud" and "exaggeration." Yet as you should know, since you are a lawyer admitted to the bar in California, fraud requires that one intentionally mislead in order to achieve some material gain. Richards's research, which you fail to address substantively, shows that Haeckel used the best available illustrations, regularly updating his illustrations as newer and better ones became available. There's no evidence of intention to deceive there, which as any lawyer ought to know, means there was no fraud.

Yes, your paper cites various sources agreeing to the "fraud" narrative, but none of them which take into account the more recent research. You refer to Dr. Richards as "the other guy," insultingly dismissing the world's foremost authority on the life and work of Haeckel. That's rather a stretch, and the fact that you neglected to cite any of his work, work available to you while researching your article, suggests that you were exaggerating (at least) the evidence against Haeckel.

You also (ahem) exaggerate in citing Michael Richardson's work. Not only did he misleadingly include the yolk sac in some but not all of phis photographs (an exaggeration which, by Luskinesque standards, would also be fraud), but he has acknowledged "Haeckel's much-criticized embry drawings are important as ⦠teaching aids, and evidence for evolution" and "ironically, had Haeckel drawn the embryos accurately, his first two valid points in favor of evolution [increasing differences between species as they develop and strong similarities between early human embryos and those of other mammals] would have been better demonstrated."

This hardly bolsters your case, Casey. This rather selective account of Richardson's views would seem to exaggerate the anti-evolution charge. Surely you know better, as these points have been made to you before, yet you continue to repeated these long-refuted claims.

There's a parable about motes and logs that you might consider here.

Josh: Did you see the new paper documenting S. J. Gouldâs manipulation of data in The Mismeasure of Man, apparently with the aim of trashing racist craniologist Samuel George Morton. If Gould was a fraud, does this invalidate Gouldâs (and Caseyâs) accusations against Haeckel. Does this mean that Casey must now condemn Gould, not to mention creationist clergy who âevangelistically speakingâ exaggerate (pure fraud, according to Luskin) their religious message? Shame, shame.
The Gould article is very interesting and only confirms my long-held opinion concerning his honesty.

Woody Benson, Campinas, Brazil

Lewis JE, DeGusta D, Meyer MR, Monge JM, Mann AE, et al. (2011) The Mismeasure of Science: Stephen Jay Gould versus Samuel George Morton on Skulls and Bias. PLoS Biol 9(6): e1001071. doi:10.1371/

By semopcoes (not verified) on 12 Jun 2011 #permalink