One of the problems with a big tent

…is that the people in your tent only share some of your views. And one of the problems with having a blog is that it’s searchable, so that when you say ‘no one in my tent ever said x,’ it’s easy to show that it’s a lie.

Within the intelligent design tent, there are people like Michael Behe, who believe that species change over time and that they evolved from a common ancestor, differing from evolutionary biologists only in their insistence that some aspects of biology must have been designed:

I am not a creationist and have no reason to doubt common descent.

There are also people in the tent like Casey Luskin, Stephen C. Meyer, and Jonathon Wells who doubt, and spend a lot of their time attacking, common descent (see “Intelligent design’s relationship with common descent? It’s complicated.“).

Figure 4 from Shubin et al. 2006. Comparison of fossil forelimbs.

Figure 4 from Shubin et al. 2006. Comparison of fossil forelimbs.

So when someone like Michael Denton says something like “…no one doubts that fins and limbs are homologous,” I’m inclined to run a search of the blog on which he said it. Surprising me not at all, Casey Luskin has a whole series of posts arguing against the homology of fins and limbs in the context of the fossil species Tiktaalik roseae:

Is evidence of a transition missing? This new fish fossil doesn’t seem to add much–if anything–to bridge the gap between fish fins and tetrapod limbs. In fact, if anything, the fin of Panderichthys appears closer to a true tetrapod limb than does the fin of Tiktaalik. I would assume that documenting how fins turned into feet would be one of the more important aspects of the fish-to-tetrapod evolutionary story. [Evolution News & Views April 11, 2006]

I’m super skeptical that this new fossil is good evidence that a transition took place… [Evolution News & Views January 23, 2008]

…one would have to imagine severe readjustments of bones that would have been necessary to effect such a transformation–readjustments that Shubin assumes in any of his claims of homology. [Evolution News & Views July 14, 2008]

…I believe that “the morphological gap” between lobe-finned fish and tetrapods should still be considered “frustratingly wide.” [Evolution News & Views August 1, 2008]

…at least some the alleged similarities to tetrapods found in these fossils do not actually represent features that are homologous to tetrapods, i.e. they are convergent similarities, also called homoplasies. This means that similarities between these lobed-finned fish fossils and tetrapods imply homology, except for when they don’t, making the Darwinian rationale for inferring “homology” appear weak and arbitrary. [Evolution News & Views September 26, 2008]

Call them what you like, but this fish fin doesn’t have anything like the digits in a true tetrapod limb. [Evolution News & Views November 1, 2010]

So the claim that “no one doubts that fins and limbs are homologous,” like the one that “No One — No One! — Denies the Interconnectedness of All Life” is a straight up lie. Cdesign proponentsists want to say that their critics are attacking a straw man, that we dishonestly portray them as creationists who don’t believe in well-established facts such as common descent. The problem with that version of reality is that quite a few of the people standing in their tent really don’t believe those things.


Stable links:

Shubin NH, Daeschler EB, Jenkins FA (2006) The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb. Nature, 440, 764–771.


  1. Crimson Clupeidae says

    I’ve been dealing with these clowns (and that’s insulting to actual clowns) for years. They all pretend not to read each others material if it contradicts their own. They quickly cite one another though (as a growing consensus!!) when they have a point or two on which they do agree.

    It’s all a game of smoke and mirrors. I’ve become convinced that about half of the cdesign proponentsists are in it as grifters and the other half are true believers.

    • hoary puccoon says

      You think only half of the cdesign proponentsists are grifters? Wow, you have a lot more respect for their honesty than I do.

  2. Reginald Selkirk says

    I have a colleague who is sympathetic to Intelligent Design. Mostly he fails to inquire deeply because he enjoys his religious affiliation. He points to Behe as an ID ‘thought leader’ who is somewhat scientifically knowledgeable. I elaborate for him what Behe seems to believe: that the universe and earth are old, that natural selection happens, that evolution happens, that all life on Earth shares common ancestry; but that occasionally God steps in to poof into existence something which is too complicated to evolve on its own, like a bacterial flagellum or a blood-clotting system.

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