2 + 2 = 17, for certain values of 2


A while back, I responded to Behe/Luskin’s claim that his model proving the impossibility of evolution of chloroquinone resistance was vindicated. I pointed out (as did Ken Miller) that showing that a particular trait required multiple point mutations did not affect the probability in the naive way that Behe and Luskin calculated — in particular, it did not require that the mutations be simultaneous. We’re familiar with a great many known mutations that involve multiple sequential hits to have their effect. I mentioned the work on steroid receptor evolution, and how cancer is an amazing example of the power of the accumulation of sequential variants.

Behe fired back, issuing a challenge to ‘show my numbers’. If he could have said anything to confirm that he was obliviously ignoring my point, that was it, and so I blew him a raspberry and ignored his challenge. I wasn’t arguing with his numbers, and we could even use his very own set of numbers — my point was in the operation he was doing with those numbers. His assumption is that you must have two mutations occur simultaneously, in the same individual, so that you simplistically multiply the probabilities together to get an improbably low frequency. I’m saying that’s invalid: these mutations can happen independently, they can accumulate to some frequency in the population, and then a second mutation can occur.

Now Larry Moran has carried through on the calculations. Using the known data on mutation rates, and throwing away Behe’s bogus demand that everything occur in the very same instant, he shows that the evolution of chloroquinone resistance ought to be rare, but not at all impossible, and with frequencies that are in the ballpark of what is observed.

Furthermore, Moran describes a paper that quantifies the presence of malaria strains in the population that contain pieces of the resistant combinations and that further describe the sequential series of mutational events that led to the most resistant strains.

All of the strains (except D17) are found in naturally occurring Plasmodium populations and the probable pathways to each of the major chloroquine resistant strains are shown. It takes at least four sequential steps with one mutation becoming established in the population before another one occurs.

None of the mutations occurred simultaneously as Behe claimed in his book.

The intelligent design creationists are somehow still crowing victory. I don’t quite understand how — their premises have been demolished, they’ve been cut off at the knees, but I guess their followers are easily bamboozled if they shout “math!” loud enough. Even if the math is wrong.

Comments

  1. Markita Lynda—threadrupt says

    It’s amazing how obtuse one can be when one’s income depends on one’s obtuseness. Behe has sold his intellectual integrity, if he ever had any, for money.

  2. says

    The creationist ranks are loaded with math abusers who chortle about their “proofs” despite having little understanding of what they are saying. Usually their grasp of probability is particularly weak. Odds are, they’ll never figure it out.

  3. marcoli says

    An even simpler point to bring up is that the malaria parasite has SEX when in their mosquito hosts. So there is a chance that cells containing one or more of the mutations will combine genomes with cells containing another mutation.

  4. says

    “Furthermore, Moran describes a paper that quantifies the presence of malaria strains in the population that contain pieces of the resistant combinations and that further describe the sequential series of mutational events that led to the most resistant strains.”

    I think that paper is the one Behe saw as vindication in the first place…although his argument doesn’t make sense on multiple levels, see Moran’s piece or my comment on it lower down.

  5. Artor says

    Usually their grasp of probability is particularly weak. Odds are, they’ll never figure it out.

    *Gasp* You just proved them right! At least, as far as they can understand.

  6. alkisvonidas says

    The intelligent design creationists are somehow still crowing victory. I don’t quite understand how

    Man at Delivery Address: I hope in time you realize how stupid you are.
    Philip J. Fry: I wouldn’t count on it.

  7. says

    Nick Matzke wrote over at Sandwalk,

    Also, no, it doesn’t mean the mutations had to be simultaneous and, no, it doesn’t confirm Behe’s preferred probability estimate of 1 in 10^20. Behe gets that number from a paper that offers it only as an informal, offhand estimate. It’s not the product of a serious study, and it’s not clear that the author (White, IIRC) even knows very much about population genetics.

    Exactly. Back in 2007, I tracked down this number. It comes from N. J. White, “Antimalarial drug resistance” Journal of Clinical Investigation 113, 8 (2004): 1084–92.

    Resistance to chloroquine in P. falciparum has arisen spontaneously less than ten times in the past fifty years (14). This suggests that the per-parasite probability of developing resistance de novo is on the order of 1 in 10^20 parasite multiplications.

    Reference 14 is X. Su et al., “Complex Polymorphisms in an ∼330 kDa Protein Are Linked to Chloroquine-Resistant P. falciparum in Southeast Asia and Africa” Cell 91, 5 (1997): 593–603. What that paper says is that at the time, independent chloroquine resistant strains had been observed in two different places. (Later, this number went up to four.) But that’s not the same as saying that the mutation itself occurred twice in all of history. As Matzke says,

    As I pointed out in my review of Behe in 2007, just because there are, say, about a dozen independent originations of chloroquine resistance (CQR), doesn’t mean you can take this number, divide by the cumulative population size of malaria since chloroquine was introduced, and call it a day. Those dozen are just the CQR originations that were (a) successful and (b) widespread enough to be detected as of 2004. But it could be that CQR would originate 10 times a year in each population, but the only one you will detect is the first one that is lucky enough to get to whatever minimum frequency guarantees selective sweep through the population. New CQR mutations after the sweep is on won’t have a chance.

    (Emphasis added.)

  8. Crimson Clupeidae says

    So, we have to red the Monty Python Black knight scene with Behe?

    That sounds about right.

  9. says

    You have to admire their understanding of their marks. Scientifically illiterate AND unable to even put two and two together. I wonder if any of them have noticed how Behe with his E. coli flagellum lies is ‘proving’ the ‘Intelligent Designer’ gave E. coli something to make it better at making us sick, and is now ‘proving’ he’s done the same with malaria.

    Not sure now which is my favourite ‘Intelligent Design’ fallacy.

  10. bcwebb says

    Myers is clearly wrong because it’s simple enough to prove with probability theory that PZ Myers does not exist and therefore has to be wrong. Everyone knows that the odds of a person surviving and having children while not small is finite, about 85%. Yet this PZ Myers claims that not only did his parents have children but so did his grandparents and back through the generations. With his parents he only needed two; but with grandparents, four; and great grandparents, eight. [Now if there are rednecks or Royalty in the family not as many are required because one parent can have multiple functions.] The further you go back the more unlikely it becomes. The probability of PZ Myers lineage is P=0.85^(2^n) . Even six generations back the odds are 0.85^64 or 30ppm. If we go back ten generations the odds are less then 10^-72. If we go back to the start of the world (5000 years, or about 200 generations) the odds are 10^-(10^59). Clearly PZ Myers is so improbable as to not exist at all. Therefore, ergo, GOD. QED.

  11. vereverum says

    I’m not a biologist but I do like to understand things. So a question, but forgive the terminology. Given a mutation, call it M, to a gene which will eventually spread throughout the population. Is Behe arguing that mutation M deterministically prevents any other gene in the organism from mutating as to interact with M and change a trait?

  12. bcwebb says

    @vererum
    Behe is doing something like the nonsense I wrote above: if four mutations are required in a cell to give drug resistance, he calculates the probability of them all occurring in one cell simultaneously, rather than including the appearance of the separate mutations as variants within the population which means that there only need be a cell that has a lineage that includes cells from the populations of cells with each mutation. (Well, also, that that cell happens enough times to create a sustainable population, helped to increase in number by it’s higher survival rate. Incomplete drug treatments help out this process by eliminating the competition.)

  13. vereverum says

    @bcwebb
    Thanks, I now have a better understanding.
    It’s one thing to think someone is wrong but quite another to be able to articulate why they are wrong.
    Not necessarily to others but at least to yourself.

  14. maddogdelta says

    In a related sports item, Michael Behe is also claiming that the only possible scores in basketball are 1-0, 2-0 and 3-0, because everyone knows how unbelievably impossible it is for a basketball to go through a hoop, on 2 different ends of the court 40 or 50 times all at once.

    CHECKMATE SPORTSTHEISTS!

  15. Amphiox says

    Re @12;

    So PZMyers, clearly, is the product of intelligent design.

    The intelligent designer deliberately designed a being dedicated to proving that he (the designer) does not exist.

    It is up to the theologians to work out the implications of this.

  16. anteprepro says

    Cdesignism: No matter how many slices you add up, no matter how far you transition up the body, no matter how many microcuts you get building up into a macrocut, it is always still “Just A Flesh Wound”.

  17. kraut says

    So Behe’s “designer” wants to counteract human efforts to control the spread of P. falciparum and prevent the misery caused by it by designing resistance?
    And he thinks such a being is praiseworthy? Or what are Luskin and Behe trying to say? i am as usual confused by the logic of creationist bull.