Mt. Improbable, Revisited

A few posts back I engaged a discussion about Richard Dawkins’ metaphor of “Cimbing Mount Improbable” for the proces by which evolution by natural selection crafts complex structures from simpler precursors. Since I did not have his book in front of me at the time, I was working from memory.

As it happens, earlier today I was browsing through The God Delusion and I came across a description of the metaphor which, I am pleased to say, expresses precisely the view I attributed to Dawkins. You will find this on pages 121-122:

In Climbing Mount Improbable, I expressed the point in a parable. One side of the mountain is a sheer cliff, impossible to climb, but on the other side is a gentle slope to the summit. On the summit sits a complex device such as an eye or a bacterial flagellar motor. The absurd notion that such complexity could spontaneously self-assemble is symbolized by leaping from the foot of the cliff to the top in one bound. Evolution, by contrast, goes around the back of the mountain and creeps up to the gentle slope to the summit: easy! The principle of climbing the gentle slope as opposed to leaping up the precipice is so simple, one is tempted to marvel that it took so long for a Darwin to arrive on the scene and discover it. By the time he did, nearly three centuries had elapsed since Newton’s annus mirabilis, although his achievment seems, on the face of it, harder than Darwin’s.

Glad we cleared that up.


  1. #1 tresmal
    August 2, 2008

    By the time he did, nearly three centuries had elapsed since Newton’s annus mirabilis

    Three centuries? Wasn’t it closer to two?

  2. #2 Jud
    August 2, 2008

    Unless you’ve read it already, let me recommend one of Gould’s lesser books, Full House. While the writing didn’t grab me as much as some of Gould’s others (very repetitive), one idea is worth noting in the context of Dawkins’ “climbing” metaphor.

    You’ll remember my problem with the climbing metaphor is that (to me, anyway) it implies the notion of goal-direction. There’s a mountain; why should an otherwise random path choose to go up, against the force of gravity? Non-goal-directed paths generally don’t choose a consistent direction against physical laws: when’s the last time you saw the course of a river climb a mountain, rather than run down one?

    In Full House, Gould introduces the following idea: Life Begins, in some primitive form. From there, if evolution is random, it will proceed in directions both more and less complex. But if it becomes less complex, it’s no longer Life As We Know It. So life has evolved in random fashion, but while that evolution has produced a great variety of more complex species (though as would be expected, most new forms are simple – there is a far greater variety of simpler life forms, such as bacteria, than more complex ones) there is nowhere to go in the less-complex direction. Thus the appropriate metaphor is not a path up a mountain, but rather something like the growth of a bush planted right against the side of a wall, branching off randomly in all directions in one hemisphere (as simple, more complex), but unable to grow at all in the other direction (less complex).

  3. #3 MikeO
    August 3, 2008


    The concern regarding ascribing ascent of the hill as being “goal-oriented” is an understandable artifact of the metaphor. The progress up the “hillside” of the mountain is not necessarily direct. There may be crevices and potholes which describe the slippage of complex forms back down to less complexity. All of evolutionary advance appears to be anti-entropic, but in the mountain-organism-environment system we understand that it isn’t so. At the level of the individual selection juncture, the more fit form is able to make the upward climb, against gravity or against more efficient energy utilization.

    I prefer Dawkin’s metaphor to your bush metaphor and suggest that metaphors are tools of communication that cannot be prototypic, by definition. Mount Improbable is a model which I think communicates quite well to all but those who have trouble visualizing either the mountain or the fact that less-complex forms tend towards more-complex forms to solve the crisis at the selection junction.

    Perhaps Darwin’s ideas are too complex to ascribe to metaphor. Certainly, the development of the eye would seem miraculous if one chooses to ignore the less dramatic sets of minor changes leading to fitter forms which have occurred in so many examples.

  4. #4 tresmal
    August 3, 2008

    MikeO: I think you’re addressing Jud’s comment. Mine was the nitpicky one about the elapsed time between Newton and Darwin.

  5. #5 Leni
    August 3, 2008

    Yah. It should be two centuries.

    Maybe we should put Dawkins’ head on pike though, just to make sure it never happens again 🙂

    JJ, is this on your list?

  6. #6 fongooly
    August 4, 2008

    Leni, don’t forget your specialty is motherpucking, not fatherpiking.

  7. #7 Jud
    August 4, 2008

    MikeO wrote: Mount Improbable is a model which I think communicates quite well to all but those who have trouble visualizing…the fact that less-complex forms tend towards more-complex forms….

    My trouble with the Mount Improbable model is precisely that it makes people think it is a “fact” that “less-complex forms tend towards more-complex forms.” There is no such “fact” in evolutionary theory of which I’m aware. If you can find some support for an evolutionary tendency favoring complexity in a current textbook or other reliable source (that isn’t simply an artifact of poor writing), I’d appreciate knowing about it.

  8. #8 Larry Moran
    August 4, 2008

    Jason says,

    Glad we cleared that up.

    I don’t think your interpretation of the point Dawkins was making with his mountain climbing metaphor was in dispute. Was it?

  9. #9 Bill Rohan Sr
    August 4, 2008

    “But I want to believe that, through the eyes of my faith, this is how God created the world and that God cares about that world.” Giberson

    “I want …”
    Why does a person “want” to believe something about a god or more basically “want to believe” there us a god to believe in?

    Why not “not want to”?

    You don’t need a supernatural being to explain anything. It is an idea which interferes with understanding. It contaminates it. No knowledge is added or reached by saying “this is the way god does things” in regard to evolution (or anything else).

    “I want to believe there is a supernatural being who designed evolution. I see order, complexity, causal relationships, great duration and diversity in nature. I know there is a supernatural being, though I can’t sense that that being I feel “him”. I believe, actually I really know but can’t prove it to others. Right now a supernatural participation in every thing that was, is, or will be. Don’t you see, there has to be! I feel it!”

    Some want that version of life and living. It would be difficult to not want that version once it is an identity that renounces any knowledge that contradicts it.

  10. #10 Ivar Husa
    August 5, 2008

    I suppose (a hunch, only) that there is a net directionality arrow that tends to point in the direction of complexity, simply because there could be (part of my hunch) more ecological niches that are available to more complex ctitters. The ‘less complex’ niches are more thoroughly occupied with existing life forms. A life form attempting to occupy a ‘simpler’ niche just has more competition, and so is less likely to survive, on average.

  11. #11 ahmet
    August 9, 2008


  12. #12 sagopa
    August 9, 2008

    douv plesan hdy

  13. #13 pesimisting
    August 9, 2008


  14. #14 georghede
    August 12, 2008

    thnaksh l?d

  15. #15 zuhanna
    August 12, 2008


  16. #16 Jason Kreul
    August 12, 2008

    Jud said:
    “My trouble with the Mount Improbable model is precisely that it makes people think it is a “fact” that “less-complex forms tend towards more-complex forms.” There is no such “fact” in evolutionary theory of which I’m aware. If you can find some support for an evolutionary tendency favoring complexity in a current textbook or other reliable source (that isn’t simply an artifact of poor writing), I’d appreciate knowing about it.”

    I think that the problem you are looking at here is better explained by Matt Ridley in a book called “The Red Queen.”

    Ivar Husa has a good point about all the lesser niches being filled early in the game. This is also a valid point, but we must understand that not all selection is due to sexual preferences. Ridley’s point is that survival itself is an arms race between predator and prey, between mates, between mother and child, all looking out for their own individual best interests.

    Another point to digest in this argument is the Baldwin Effect originally put forward by James Mark Baldwin in 1896 and further explored in detail by Daniel Dennett suggests something similar to your bush idea attributed to Steven Gould. Baldwin assumed a rate of random mutation some of which were “good tricks” and some of which were detrimental to the life of the organism. Unfortunately, detrimental mutations are just that, detrimental to the organism’s reproductive success. On the other hand, some mutations are neutral or offer a net benefit to the organism. These characteristics, are passed on to the organisms progeny.

    We must understand that not all organisms in a population are homogeneous. There is localized pockets of random variation within every group, so in essence, your argument is partially correct. There is no ONE path up Mount Improbable, and certainly, Richard Dawkins knows this fact. I have not personally read every scrap of paper the man has written but I have read enough to make this educated assumption that his simplification was just that.

    You people need to get over yourselves and quit scrutinizing every syllable this man utters in search for a loophole. Dawkins sometimes make the assumption that at least a portion of his audience has done their homework and will understand where he is coming from. In that, he is entirely correct, the problem is that many of those listening are far from being fans of his work.

    Your comment that there is no FACT to back up Dawkins proves a certain naivete about scientific method. We cannot ever PROVE any FACT in science. There is no guide that states “ok when you get to this point, your theory will never be disputed.” This simply does not happen in the real world. We simply observe the occurrences, make inferences about how we think things will behave in the future, and wait for someone else to disprove our hypothesis or support it with other evidence. In Dawkins’ case, the supporting evidence by authors too numerous to list on Jason’s blog do support the gneeral claim towards climbing Mount Improbable.

  17. #17 Bill Rohan Sr
    August 18, 2010

    The social world, the symbolized, the world of spoken meaning is a niche nested in the natural world that science knows about. All human interaction is linguistically enabled.

    Science has not yet been able (if ever) to account (fully) for the humanly experienced world. Culture with all its complexity and variety seems to require the acceptance of an idea such as “transcendent” (or if you prefer a “capacity for abstraction”) to account for the symbolized world of the human species.

    The idea “transcendent” seems to strain at least, but more likely is not consistent with the space/time/matter idea of a lawful mechanized physical universe. A degree of freedom seems evident at even the behavioral level of culture, but more obviously at the linguistic level of symbols. They seems to require a recognition of an X that empirical science cannot recognize as legitimate within the empirical perspective.

    Therefore, either naively or dishonestly, science takes X for granted. It must be taken as a given to proceed because the enigma of the relation of the objective and X (subjective, consciousness?) has not yet been resolved.

    I have unique direct access to a manifold of experience that is only available to you through communication symbols. And you?

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