Zachriel
Posts: 2723
Joined: Sep. 2006
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O'Leary
| Quote | | Recently, a comment by a Lance Duval appeared in the combox for the Post-Darwinist’s “Marsupial frogs: Another reason to check out of Darwinism”. Duval trashed ID embryologist Jonathan Wells, arguing that Darwin never really believed in recapitulation of embryos and that it has not been taught in textbooks since the 1920s. |
Haeckel proposed that embryos go through all the stages of the evolution of an organism, so a human embryo becomes a fish, then a reptile, then a mammal, etc. Of course, this strong version of Haeckel's theory has been discarded, but the fact remains that ontology and phylogeny are very closely related; so much so that various species of embryos can be hard to distinguish. Here are images of three different mammalian embryos at comparable stages in their development.
http://uk.geocities.com/simon_balfre/embryo.htm
Then there's O'Leary's use of a selective quote.
| Quote | | B. I. Balinsky, An Introduction to Embryology (1975), pp. 7-8: “Features of ancient origin develop early in ontogeny; features of newer origin develop late. Hence, the ontogenetic development presents the various features of the animal’s organization in the same sequence as they evolved during the phylogenetic development. Ontogeny is a recapitulation of phylogeny.” |
O'Leary left out the next sentence, "The repetition is obviously not a complete one, and the biogenetic law states that Ontogeny is the short and rapid recapitulation of phylogeny."
The rest of the textbook quotes she provides are reasonably correct and don't support her point, probably because she doesn't actually know the differences between a fish and a frog embryo — and doesn't care to.
The quote of Darwin is especially interesting as it shows what a careful scientist Darwin was. The closest statement by Darwin to support O'Leary's claims is "On the other hand it is highly probable that with many animals the embryonic or larval stages show us, more or less completely, the condition of the progenitor of the whole group in its adult state. Yet, even that he carefully qualifies (probable, many, more or less). Darwin was working with the evidence that was available at that time. Closer to the truth is that a mammalian embryo resembles a fish embryo, not an adult fish.
From Pharyngula
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You never step on the same tard twice—for it's not the same tard and you're not the same person.
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(Don't look at me, my own little plot's gone nowhere.) 
