Where the Conflict Really Lies: Science, Religion, and Naturalism Read Online Free PDF Page B

answer to (4), (Considering each member of the series of hypothetical Xs connecting the human eye to no eye at all, is it plausible that every one of them was made available by random mutation of its predecessor?): “My feeling is that, provided the difference between neighboring intermediates in our series leading to the eye is
sufficiently
small
, the necessary mutations are almost bound to be forthcoming.” Finally question (5): Considering each member of the series of Xs connecting the human eye to no eye at all, is it plausible that every one of them worked sufficiently well that it assisted the survival and reproduction of the animals concerned? As Dawkins notes, some people claim that the obvious answer is “no”; he argues that they are mistaken. These people point to a particular structure or organ and claim that there isn’t a Darwinian series for that structure or organ; Dawkins makes suggestions as to how such a series might in fact go.
    There are two basic ways in which Dawkins’s argument is weak. First, returning to BQ, there is surely no
guarantee
that there is a not-too-improbable path through organic space from some early population of unicellular organisms to human beings, or, for that matter, to fruit flies. It might be, as Michael Behe claims, that some structures simply can’t be reached by way of small steps (each advantageous or not too disadvantageous) from preceding life forms. 28 Among his proposed examples: the bacterial cilium, the cascade of electrical activity that occurs when a light sensitive spot is hit by a photon, blood clotting, the mammalian immune system, and the complicated molecular machines to be found in any living cell. Many have rejected Behe’s specific arguments here; still, perhaps he’s right. (I consider some of Behe’s arguments in chapter 7 .) Perhaps no matter how small you make the steps, there are life forms that can’t be reached from previous forms, except at the cost of astronomical, prohibitive improbability. How could we tell that this isn’t so? True, Dawkins says that his feeling is that indeed it isn’t so; but how much confidence can we put in feelings and guesses?
    So the first weakness in Dawkins’s argument is that the premises, his answers to questions (4) and (5) above, are controversial,unsupported, and pretty much guesswork. There is no attempt at the sort of serious calculation that would surely be required for a genuine answer. No doubt such a calculation and hence an answer to those questions is at present far beyond our knowledge and powers; no doubt it would be unreasonable to require such a calculation; still, the fact remains we don’t have a serious answer.
    But Dawkins’s answers to (4) and (5) are correct; the argument is still in trouble. Recall that his answer to question (3) is yes, “provided only that we allow ourselves a
sufficiently large
series”; his answer to (4): “My feeling is that, provided the difference between neighboring intermediates in our series leading to the eye is
sufficiently small
…” But even if he is right about the answers to (3) and (4), it doesn’t follow that the whole path is plausibly possible in his sense—that is, it doesn’t follow that the path is not astronomically improbable. That is because of the temporal constraint imposed. Suppose there have been multicellular organisms for, say, a billion years. This means that the series can’t be arbitrarily long and the distance between the points arbitrarily small.
    Dawkins’s argument, therefore, is pretty weak. But what about the truth of his conclusion?
Is
there a Darwinian series for the eye, and for the other forms of life? Is Dawkins right? How can we tell? How could we determine a thing like that? Michael Behe is by no means the only biologist who thinks it’s at best extremely unlikely that there is such a series; for example, according to the biologist Brian Goodwin,
It appears that Darwin’s theory works for the small-scale