What The Haeckel

What do Haeckel's embryos signify? : Thoughts from Kansas

Casey Luskin thinks they signify fraud. Other people beg to differ.

And Matt Young writes:

My colleague Paul Strode wrote a very clear and concise explanation of Ernst Haeckel’s “ontogeny recapitulates phylogeny” law for our book Why Evolution Works (and Creationism Fails). In Chapter 11, Strode explains that Haeckel was wrong in thinking that embryos resemble the ancestral adult forms; rather, early embryos resemble the embryos of ancestral forms. In other words, Haeckel was on to something, but he didn’t get it quite right. Strode explains further, “Recapitulation nevertheless provides helpful insight into evolutionary relationships and ancestry,” and argues that von Baer’s law is closer to the truth.

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Nick Matzke writes:

Like Napoleon on Saint Helena, good ol’ Casey Luskin is re-fighting old lost battles again.
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First, Haeckel didn’t ignore the differences in embryos in the earliest period just after fertilization (differences which are visually significant but mostly fairly trivial, due to the different amounts of yolk in different vertebrate eggs) – in fact, Haeckel himself prominently diagrammed them, as I showed here back in 2006. Whoops! And such diagrams are standard in any book which gives a thorough treatment of vertebrate development, although this may not include the most absolutely introductory general biology texts.

Second, Luskin makes it out as if it’s me and NCSE against developmental biology experts like Michael Richardson (whom he quotes), and as if we ignored the textbooks that did have the classic Haeckel’s embryo drawings. But (as I find out when I go back to the 2006 article which Luskin quotes) actually, no, Richardson’s on our side, and we counted the textbooks that had the drawings – taking the numbers directly from Jonathan Wells, no less! Not good enough for Luskin.

For those who actually want to be fair-minded about it, it’s pretty clear that what happened was that in the mid-1990s, as happens every few decades, a scientist (here, Michael Richardson) discovered the real, but moderate, problems with Haeckel’s embryo drawings. This led to some some guns going off half-cocked in the media and in popular works (e.g. by Gould), and this is the stuff which Luskin cites. In the meantime, the originator of the latest wave, Richardson, learned some more about the complex history of the drawings and the even more complex history of claims and counterclaims about “scandal” by creationists – from Haeckel’s day to today – and published an updated version of his assessment. We quote the updated version, and Luskin quotes the more heated early reactions, pretending (despite knowing better) that the later assessments don’t exist. Oh well.