Evolution Intelligent Design

“Retrospective Fallacy”?

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In the July 9th, 2005 issue of The New Scientist, there appears the following passage quoting Brown University’s Ken Miller:

“It’s what statisticians call a retrospective fallacy.” It is like equating the odds of drawing two pairs in poker with the odds of drawing a particular two-pair hand – say a pair of red queens, a pair of black 10s and the ace of clubs. “By demanding a particular outcome, as opposed to a functional outcome, you stack the odds,” Miller says. What these calculations fail to recognise is that many different protein sequences can be functional. It is not uncommon for proteins in different species to vary by 80 to 90 per cent, yet still perform the same function. [Go here for the article.]

I commented on this article, and about Miller’s charge of the “retrospective fallacy” in particular, here. Miller’s point is that ID proponents like me fail to make an appropriate type-token distinction, focusing on the improbability of a particular token of a protein/gene/etc. when in fact they should be focusing on the improbability of the type of protein/gene/etc. that performs the same function as the token. This charge is unwarranted. In fact, I’ve explicitly countered this concern in my writings (notably in section 5.10 of No Free Lunch, where I assign probabilities in terms of perturbation tolerance and perturbation identity factors — these factors take into account variants/perturbations of tokens that belong to the same functional type).

Thus, what Miller means by a “retrospective fallacy” fails to apply to ID reasoning. My main concern here, however, is his statement that the term “retrospective fallacy” is common usage among statisticians. I’ve looked through my statistics and probability texts (I own quite a number) and failed to find this usage. I also looked through my books on informal logic and fallacies and again found no reference to “retrospective fallacy.” Perhaps I’m missing something. Or perhaps Miller just made it up.

I’ll write him and find out. Stay tuned.

11 Replies to ““Retrospective Fallacy”?

  1. 1
    crandaddy says:

    Hmmmm, I wonder if Doug Axe is familiar with the “retrospective fallacy” concept.


  2. 2
    jboze3131 says:

    off topic, but i dont see any post lately on the book…

    Just wanted to mention that I’m reading Signs of Intelligence (the only book the library had in from Mr. Dembski- Bill edited this particular book) and I’m finding it very insightful. Reading all of it but going back and forth between different papers within (started at the front of the book then skipped thru a few then came back to them later..) Nice to read papers on the drive to push out strict materialism from science and society as a whole. Also interesting to see the many things in society affected by materialism.

    Thanks a lot for all the great books, papers, etc.

  3. 3
    DaveScot says:

    Gross improbability still remains even if only 10% of any protein sequence is actually required for its function. It appears Ken has no significant talent with numbers. Either that or he’s a liar.

  4. 4
    Bombadill says:

    Miller seems to have his hands in too many facets of the ID debate. He seems to have no apprehension about treading on ground which he’s clearly unfamiliar with. It almost seems that he’s on some sort of religious crusade and will be stopped by no one. I think he needs to lie down and relax before he makes himself look any sillier.

  5. 5
    johnnyb says:

    I have not read the article, but I am told that this article: http://www.ncbi.nlm.nih.gov/en.....t=Abstract

    comes to the following conclusion:

    “we suggest that functional proteins are sufficiently common in protein sequence space (roughly 1 in 10^11) that they may be discovered by entirely stochastic means, such as presumably operated when proteins were first used by living organisms. However, this frequency is still low enough to emphasize the magnitude of the problem faced by those attempting de novo protein design.”

    1 in 10^11 for a single functional protein (not necessarily _beneficial_, just _functional_).


  6. 6
    DaveScot says:

    The problem isn’t ONE protein. The flagellum, to take one common example, is composed of some 30 *interdependent* proteins. Thus even taking the 10^11 number at face value we still have a probability 1/1.e+330. And the bacterial flagellum isn’t particularly complex as far as cellular machinery goes.

  7. 7
    mmadigan says:

    Debating with K.Miller is like dining chinese…you soon find yourself still hungry.

  8. 8
    Daniel512 says:

    Retrospective fallacy? “What statisticians call”? I don’t even know what’s that and in a retrospective analysis I don’t remember my teachers speaking about “retrospective fallacy”. I also searched it in my books and neither my statistics nor my probability books speak about it. Now, trying not feeling me so a bad statistician I made a search in google and to [“retrospective fallacy”, statistics] it showed only 8 completely uninteresting results. And when I searched [“retrospective analysis”, statisticians] the only results were the pages quoting Miller. So I rested: it wasn’t me, nor my teachers… my education still seems worthy.

  9. 9
    testerschoice says:

    This link might be of assistance Daniel512.


  10. 10
    Daniel512 says:

    Just a comment on my former comment:

    What I wrote in my second google search was [“retrospective fallacy”, statisticians] not [“retrospective analysis”, statisticians] as I said before.

    Thanks for the link testers, my point is not that a retrospective fallacy does not exist but that by no means it is common to statisticians jargon or statistics practice… there is nothing like “what statisticians call”. It is not like to say “Type I error”, “Maximum likelihood” or more casual terms like “cherry-picking”. I think that if such an expression exists it is in a completely particular situation but not common to statisticians.

  11. 11
    2perfection says:

    As the algorithms for predicting the shape of a protien from is components has not yet been discovered you can make no meaningful prediction about how many possible combinations could fulfil a function.

    You can ‘assign’ all you want, but its a guess.

    “these factors take into account variants/perturbations of tokens that belong to the same functional type”


    “I also looked through my books on informal logic and fallacies and again found no reference to “retrospective fallacy.” Perhaps I’m missing something. Or perhaps Miller just made it up. ”

    Live and (dont) learn. Below is the link for ‘Naturalistic Fallacy’, notice that this is a widely understood concept that was ‘made up’ by G.E. Moore. Maybe Miller will one day be in famous for discovering the retrospective fallacy.


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