Fakery: Haeckel’s Fraudulent Embryos in Donald Prothero’s Textbook
The first lecture I attended on my first day of college at the University of California at San Diego in 1996 was for the course “History of the Earth and Evolution.” The course was taught entirely from an evolutionary perspective, and I enjoyed it thoroughly. This was just the first of many courses I would go on to take during my undergraduate and graduate studies that covered evolutionary biology in detail.
I still have the textbook for that course — it was Robert H. Dott and Donald R. Prothero’s Evolution of the Earth (Fifth Edition, 1994). Yes, that’s the same Donald Prothero who, more recently, has become a vocal defender of Darwinian evolution. Last month he was part of a small cadre of Darwin activists on the Internet who tried to invent a scandal by claiming as an example of “creationist flim flam” that an interview with Ann Gauger was filmed in front of a green screen.
The green screen depicted a biology lab — similar to the lab where Ann works but, in fact, it was a stock photo. Of course there was nothing scandalous at all about the interview, since Gauger works each day in such a lab (I’ve visited her there), does real biology bench research, and the green screen was used simply to provide a relevant but otherwise neutral backdrop effect during an interview — something that’s done all the time on TV and video. There’s not much I need to say about this — David Klinghoffer gave the issue all the response required (“Scandal! Gauger Filmed in Front of Green Screen“; see also his follow-up to the responses, here). Despite the uninteresting non-scandalous nature of this manufactured controversy, Prothero ranted:
Apparently, the tendency to fakery is rife with the creationists. … That’s creationism in a nutshell: fakery and incompetence.
It’s interesting that Prothero mentions fakery. Though there was no fakery involved in the Gauger interview, Prothero has promoted actual fakery in his textbooks.
Recently I was looking through Prothero’s textbook, doing some background research for a project I’m working on, and stumbled upon page 53 of his book, which bears the heading “Reality of Evolution.” Right under that is a diagram — Haeckel’s fraudulent embryo drawings — showing the drawings in all their full fakery:
Of course prominent evolutionary scientists like embryologist Michael Richardson called these drawings “one of the most famous fakes in biology,” and Stephen Jay Gould called them “fraudulent” because “Haeckel had exaggerated the similarities [between embryos] by idealizations and omissions.”
In case you were wondering, neither the caption nor the body in Prothero’s textbook say anything about inaccuracies in the drawings. (Nor is there anything about publishing these inaccurate drawings for the sake of providing “historical context,” or some other bogus excuse.) Rather, Prothero’s caption highlights the most inaccurate portions of the drawings to emphasize the supposed fact that embryos are “strikingly similar” in their earliest stages. Here’s the caption:
Figure 3.8 Embryos of different vertebrates at comparable stages of development. The earlier stages of development (top row) are strikingly similar in every group, regardless of their adult anatomy.
Note that each embryo begins with a similar number of gil arches (pouches below the head) and a similar vertebral column. In later stages of development, these structures are modified to yield different adult forms.
(Robert H. Dott, Jr. and Donald R. Prothero, Evolution of the Earth, p. 53 (Fifth Ed., McGraw Hill, 1994).)
The body text says much the same thing:
The great German embryologist Karl Ernst von Baer (1792-1876) showed that the development of animals was powerful evidence of their ancestry. Whether they develop into fish, amphibians, or humans, all vertebrate embryos start out very similar, with gill slits and a long tail (Fig. 3.8).
(Robert H. Dott, Jr. and Donald R. Prothero, Evolution of the Earth, pp. 51-52 (Fifth Ed., McGraw Hill, 1994).)
The text goes on to give a mixed endorsement of Haeckel’s famously false claim that “ontogeny recapitulates phylogeny”:
The embryonic history, or ontogeny, of vertebrates retains so much of their evolutionary history, or phylogeny, that the German embryologist Ernst Haeckel (1834-1919) postulated his famous “biogenetic law” in 1866. In Haeckel’s words, “ontogemy recapitulates phylogeny” — embryonic development repeats evolutionary history. Although this is true in a very general way, it is not true in detail. Many features of adult fish, for example, never appear in human embryos, and other features, such as the yolk sac, the umbilical cord, and the amniotic membrane that surrounds the fetus, are embryonic features that never appear in adults of many species. Haeckel postulated that organisms evolved by adding stages to the end of their embryonic development. We now know that new stages can be added at the beginning or at any time in development. More importantly, phylogeny is the result of a series of ontogenies, not their cause. Although the extreme elements of Haeckel’s ideas are now discredited, von Baer’s clear demonstration of the evidence from embryology is still one of the most powerful arguments for the reality of evolution.”
(Robert H. Dott, Jr. and Donald R. Prothero, Evolution of the Earth, p. 52 (Fifth Ed., McGraw Hill, 1994).)
So good for Prothero for noting that Haeckel’s biogenetic law is now recognized as false, even though he claims that “ontogeny recapitulates phylogeny” is “true in a very general way.” Nonetheless he argues that the similarities in early vertebrate embryos provide “one of the most powerful arguments for the reality of evolution.”
But of course, that “reality” is false.
As a paper in Nature stated:
Despite its intuitive appeal, the principle of early embryonic conservation has not been supported by morphological studies. Counter to the expectations of early embryonic conservation, many studies have shown that there is often remarkable divergence between related species both early and late in development, often with little apparent influence on adult morphology.
(Alex T. Kalinka et al., “Gene expression divergence recapitulates the developmental hourglass model,” Nature, Vol. 468: 811-814 (December 9, 2010) (internal citations removed) (emphases added).)
Or, as an article in Trends in Ecology and Evolution stated:
Von Baer’s law implied that early embryos should bear the greatest resemblance to one another. Yet despite repeated assertions of the uniformity of early embryos within members of a phylum, development before the phylotypic stage is very varied. Not that von Baer’s law is invalid. Rather, embryos do not necessarily display the greatest similarity at the outset of development.
From cleavage to gastrulation, embryos can take several paths, including extreme variation in egg size and divergent patterns of cell division. In sea urchins that brood their larvae or develop without a larval stage (direct development), cells can be reassigned to different lineages than their close relatives with larvae. In two annular fishes, Cynolebias whitei and C. nigripinnis, a single embryo develops from two embryonic centres (double blastomeres) in the one egg. Midway through the phase of cell movement the two centres begin to fuse; by the end of this phase (epiboly), deep cells have dispersed, intermingled and reaggregated to form a single population from which a single embryo develops.
The various forms of gastrulation include, for example, the presence of a blastodisc and primitive streak (typical of birds), rather than a spherical blastula and blastopore (typical of amphibians) in direct-developing, egg-brooding hylid frogs such as Gastrotheca riobambae and G. plumbea.
(Brian K. Hall, “Phylotypic stage or phantom: is there a highly conserved embryonic stage in vertebrates?,” Trends in Ecology and Evolution, Vol. 12: 461-463 (December, 1997) (internal citations removed) (emphases added).)
(We’ve also extensively reviewed some of the early differences between vertebrate embyros; see “Caught in Contradictions, PZ Myers Claims ‘Evolutionary Theory Predicts Differences as Well as Similarities’ (and Therefore Predicts Nothing).”)
Both of the sources above go on to claim that there is a conserved midpoint stage of development, the pharyngula or phylotypic stage. However, even that midpoint stage of conservation has come under fire, as we discuss in “Challenging the Precious Pharyngula.” Nonetheless, they make it clear that, as the first paper puts it “The principle of early embryonic conservation has not been supported by morphological studies”; or as the second paper says, “Embryos do not necessarily display the greatest similarity at the outset of development.” This pretty decisively topples Prothero’s claim that “all vertebrate embryos start out very similar,” and that these similarities provide “one of the most powerful arguments for the reality of evolution.”
So there you have it. Donald Prothero — the same guy who got so worked up about “fakery” in Ann Gauger’s interview — has promoted fake claims to students about embryos and evolution using faked drawings. I was one of those students.
I’m not asking for an apology from Dr. Prothero. But given his history which clearly shows how much he enjoys making personal attacks upon the character of Darwin-skeptics, if he does respond, somehow I don’t think an apology is what I’m going to get.