Revisiting Those Pesky Embryo Drawings
A few years ago, former NCSE-spokesman Nick Matzke called complaints over the use of Haeckel's embryo drawings in textbooks a "manufactured scandal." However, a variety of leading scientific authorities -- proponents of neo-Darwinian evolution -- have also complained about the use of these drawings and the way that embryology is used to support evolution in biology textbooks. Are these authorities in on the big conspiracy to "manufacture" this "scandal" too? Here's where things stand today:
Despite the fact that (in 2010 at least) out-dated concepts like "ontogeny recapitulates phylogeny" have been almost completely removed from new textbooks and that many (though not all) new textbooks use embryo photographs instead of fudged drawings, an examination of both recent textbooks and complaints from authorities within the scientific community show that there are still severe problems about how embryology is used to support evolution in biology textbooks. It's worth noting that many of the positive textbook corrections in this area came because Dariwn-doubting scientists like Jonathan Wells exposed inaccuracies in textbooks.
I've come in for some fairly harsh attacks for making the simple observation that textbooks in use today, in arguing for evolution, still use Haeckel's fraudulent embryo drawings to inaccurately portray the embryological evidence. While I doubt that some of my critics have any interest in having their mind changed, I hope the following documentation in a series of 2 posts, taken from my recent article "The Constitutionality and Pedagogical Benefits of Teaching Evolution Scientifically" in the University of St. Thomas Journal of Law & Public Policy, will convince the open-minded reader.
Those Pesky Embry Drawings
In August 2008, The New York Times reprinted material from the NCSE claiming that the 19th century embryologist Ernst Haeckel's "longdiscredited drawings" of vertebrate embryos have not been used in textbooks since "20 years ago."261 That Haeckel's drawings were fraudulent and have been used in textbooks is essentially beyond dispute,262 but the reality is that multiple biology textbooks have been used within the past 20 years that still use Haeckel's drawings to promote evolution.263
In a 2000 article in Natural History, Stephen Jay Gould recognized that Haeckel's drawings not only fraudulently obscured the differences between the early stages of vertebrate embryos, but that they were used inappropriately in textbooks:
Haeckel had exaggerated the similarities by idealizations and omissions. He also, in some cases--in a procedure that can only be called fraudulent--simply copied the same figure over and over again. At certain stages in early development, vertebrate embryos do look more alike, at least in gross anatomical features easily observed with the human eye, than do the adult tortoises, chickens, cows, and humans that will develop from them. But these early embryos also differ far more substantially, one from the other, than Haeckel's figures show. Moreover, Haeckel's drawings never fooled expert embryologists, who recognized his fudgings right from the start.
At this point, a relatively straightforward factual story, blessed with a simple moral story as well, becomes considerably more complex, given the foils and practices of the oddest primate of all. Haeckel's drawings, despite their noted inaccuracies, entered into the most impenetrable and permanent of all quasi-scientific literatures: standard student textbooks of biology. . . .We should therefore not be surprised that Haeckel's drawings entered nineteenth-century textbooks. But we do, I think, have the right to be both astonished and ashamed by the century of mindless recycling that has led to the persistence of these drawings in a large number, if not a majority, of modern textbooks!264
Gould also quotes embryologist Michael K. Richardson, acknowledging the widespread use of Haeckel's drawings in textbooks:
If so many historians knew about the old controversy [over Haeckel's falsified drawings], then why did they not communicate this information to numerous contemporary authors who use the Haeckel drawings in their books? I know of at least fifty recent biology textbooks which use the drawings uncritically. I think this is the most important question to come out of the whole story.265
Likewise, in an article titled Haeckel's Embryos: Fraud Rediscovered, the journal Science recognized that "[g]enerations of biology students may have been misled by a famous set of drawings of embryos published 123 years ago by the German biologist Ernst Haeckel. They show vertebrate embryos of different animals passing through identical stages of development. But the impression they give, that the embryos are exactly alike, is wrong."266 The article quotes Richardson by stating that "[i]t looks like it's turning out to be one of the most famous fakes in biology."267
Elsewhere, in the journal Anatomy and Embyrology, Richardson and other embryologists acknowledge that Haeckel's fraud has had a non-trivial influence on both evolutionary thought and evolution education:
Haeckel's ideas soon came in for strong criticism. His drawings are also highly inaccurate, exaggerating the similarities among embryos, while failing to show the differences (Sedgwick 1894; Richardson 1995; Raff 1996). Sedgwick (1894) argued that even closely related species of vertebrates can be told apart at all stages of development, but that the distinguishing characters are not necessarily the same as those used to distinguish among adults. . . . . Another point to emerge from this study is the considerable inaccuracy of Haeckel's famous figures. These drawings are still widely reproduced in textbooks and review articles, and continue to exert a significant influence on the development of ideas in this field.268
[Note: This excerpt is from Casey Luskin, "The Constitutionality and Pedagogical Benefits of Teaching Evolution Scientifically," University of St. Thomas Journal of Law & Public Policy, Vol. VI (1): 204-277 (Fall, 2009). For the full article, click here]
[262.] Even Matzke and Gross recognize that "Haeckel did exaggerate similarities in very early embryos of different species, and his figures, or derivatives of them, have appeared in a few textbooks." 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).
[263.] See Casey Luskin, What Do Modern Textbooks Really Say About Haeckel's Embryos? (Mar. 27, 2007) (citing several examples).
[264.] Stephen Jay Gould, Abscheulich!(Atrocious!), NATURAL HISTORY, Mar. 2000, at 42, 44--45.
[265.] Id. at 45.
[266.] Elizabeth Pennisi, Haeckel's Embryos: Fraud Rediscovered, 277 SCIENCE 1435, 1435 (1997).
[268.] Michael K. Richardson et al., There is No Highly Conserved Embryonic Stage in the Vertebrates: Implications for Current Theories of Evolution and Development, 196 ANATOMY AND EMBRYOLOGY, 91, 92--104 (1997) (internal citations omitted).