SOME of this was discussed in our three-part series, The Inevitability of Evolution, which starts here. We began that series by saying:
Perhaps the second-most ignorant of the common objections to the theory of evolution (after the ever-popular “Why are there still monkeys?”) involves some kind of objection based on the imagined “odds” against this or that biological feature appearing “completely at random.”
Those essays are primarily about the alleged impossibility of evolutionary developments, although we briefly mentioned the wider applicability of the “odds” fallacy when we said:
This kind of argument — which is essentially saying “I don’t believe it!” — could be employed against more than evolution. A creationist could look at the current totality of English history, or the biosphere, or whatever, and impulsively exclaim that it’s “impossible” for such to have occurred without outside guidance. But is it really?
If England is impossible, so of course is the rest of human history. So are you, because the innumerable events leading to your conception are vast beyond comprehension. Everything is impossible to such a mentality. At what point does reductio ad absurdum intervene to put an end to this nonsense?
Because this “odds” fallacy has much greater applicability than evolutionary sequences, it deserves a proper name and a stand-alone discussion. We’ve been calling it the Fallacy of Retrospective Astonishment. That’s a mouthful, but its a good, descriptive name.
This fallacy is frequently encountered when someone looks out at the world, gets a dazed, uncomprehending look on his face, and declares that it’s all so complicated, so wonderful, and so impossible, that it’s “obviously” the result of a supernatural miracle worker.
The gob-smacked person proclaiming such a miracle is probably not aware of the process that brought him to his conclusion. If we break down his “thinking,” we’d find that he’s looking back to some earlier and arbitrarily chosen initial state, then speculating on all the nearly infinite events that might have happened (but which didn’t happen) between then and now, and concluding that the present state of affairs has such a low degree of probability that it must have been impossible to achieve by natural means.
Our response is that this “reasoning” makes virtually everything impossible, and it’s therefore an absurdity. Things only seem improbable in retrospect. As Rick said in Casablanca: “Of all the gin joints in all the towns in all the world, she walks into mine”
Consider the reverse. If the present seems improbable, given some starting point in the past, imagine how much more unlikely it is to prospectively predict the present from a vantage point in the past.
It is most unlikely that some ancient seer, with all the possible intervening variables, could have accurately predicted the present. Except for the simplest, non-volitional systems (e.g., the movement of the planets), from any arbitrarily selected starting point, anything beyond the immediate future cannot be predicted except in the most vague and therefore meaningless terms.
But while predicting the future is all but impossible, as is predicting the present by someone in the past, that doesn’t justify anyone in looking back from today and claiming that the present is an impossible miracle. Let’s take a simple example. Go through your family records and identify each one of your great-great-etc. grandparents, ten generations ago.
Assuming no incest or cousin matches, there should be 1,024 of them — that’s 210. This will be our initial state; we’ll start with their existence as a given. Okay, for every one of your ancestors in that generation, compute the odds that each would encounter and marry his (or her) spouse. How you do that is up to you, but it’s only the first step.
After you’ve worked that out, let’s consider their children — the ninth generation before you. Your task is to compute the odds that each one of those ancestors got born. Each birth implies a moment of ancestral ecstasy at just the right time, when the right ovum was present to encounter the right spermatozoan. Considering the nature of such things, each unique conception event is an unlikely occurrence.
Go ahead and do the computations, first for one ancestor’s birth, and then for each of your other ancestors in that generation. When you’re done, you will have computed the odds that all 512 of them, the whole set in that generation, would get born.
Then, somehow, compute the odds for each of those children surviving to adulthood. When you’ve done that, do the earlier-described computation about the odds that each ancestor in this new generation would encounter his (or her) spouse. Now, notwithstanding the odds, you’ve got that generation born, raised, and married. We’re ready for them to produce each known individual in the 8th generation of your ancestors.
If you’ve accomplished this for the earlier generation, you’ve somehow figured out a procedure for it, so go ahead and do it again for this latest set of children. The next step is that they have to survive, meet their spouses, and then produce precisely the necessary offspring for the 7th generation. Compute those odds. Then do it for the the 6th generation. Keep going.
After you’ve done all that, do one final computation and calculate the odds against all of these events happening for all ten generations, until we finally get to you.
When you get that all worked out, you will have done what no one has ever done before — you will have computed the odds against your own existence, given the initial conditions of ten generations ago. Having completed this mathematical task, perhaps you will conclude that your existence is literally impossible.
So what are you doing here? And where do we go with all of this? What’s the purpose of doing such calculations?
The first point to be made is that computing the odds against known historical events, such as the existence of yourself, is a staggeringly difficult enterprise. The next point is that there is no reason for you to cover all those pages with mathematical scribbling, because it doesn’t really matter how high the odds are. The lesson to be learned from your calculations is already known. Your existence astronomically unlikely.
Yet here you are. And it’s not only you — we’re all here. But if we consider the odds, none of us should be here. Is it all a miracle?
We don’t think it is. It’s true that each moment in the world is the result of a blindingly complicated mix of factors. We can’t compute all the variables, yet from our knowledge of physics, chemistry, and biology, as we look around we can be fairly confident that each moment of the day things are functioning in accordance with their nature.
Mull that over. We never see impossible things happening. It’s true — trivially true — that the hypothetical “odds” against things being the way they are today seem astronomically high. But so what? Despite all your calculations, nothing that has happened in the past was even remotely impossible, and therefore today isn’t impossible either.
Here’s the bottom line, our rebuttal of the Fallacy of Retrospective Astonishment: Long chains of natural causes and consequences happen all the time. In fact, that’s what reality is made of. Thus we present our own Rule of Reality: If each event in a causal chain is a natural occurrence, then the historical totality of the whole chain of events is also natural — and not at all impossible. This is a chronological corollary of that well-known principle: The whole is equal to the sum of its parts.
If you care to look at things in terms of the odds, each of us is a biological lottery winner merely for having been born; and this present moment with all of us together is the consequence of an enormous mega-lottery. Were the clock to be re-wound to ten generations ago and then started again, we probably wouldn’t be here. But there doesn’t seem to be any cosmic reset button. That’s good for you, not so good for your imaginary replacement, Clyde, who might have been conceived in your stead.
If, on the other hand, you choose to assume that the hand of Providence was guiding each moment of the past in order to produce your own commendable person, that’s fine with us; but you must also acknowledge that the same Invisible Hand (apologies to Adam Smith) is responsible for every tyrant, maniac, retardate, and birth deformity in the world. Nature’s lottery is, at least, free from any suspicion of malevolence.
Here’s our final conclusion: Although there’s no evidence that we’re the product of any impossible events, each of us is the result of a unique series of natural occurrences. Our existence will never be repeated. We’re irreplaceable. Priceless. This is why — contrary to the endlessly repeated claims of the creationists — the theory of evolution places a far higher value on individuals and all of humanity than creationism, according to which we could be wiped out and started up again on a whim.
Now get out and have a nice day. There will never be another like it.
Copyright © 2009. The Sensuous Curmudgeon. All rights reserved.