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Evolution by Blind Guidance Is Really Just Unguided Evolution


I’ve been having an ongoing discussion of my book — Undenable: How Biology Confirms Our Intuition That Life Is Designed — with my friend Hans Vodder (see here for all posts). As a theistic evolutionist, Hans thinks God may well have used Darwinian evolution to create the full diversity of life. Undeniable didn’t persuade him otherwise, and while he hasn’t convinced me that I got it wrong, I do want to know how two people with similar worldviews can think so differently about origins.

Imagine a Sandstorm

Suspecting that we may attach different meanings to the word natural, I previously asked Hans to imagine a sandstorm producing a magnificent sculpture of a human. My point was that if we were to witness such a thing, we would instantly know that this was no ordinary (i.e., natural) sandstorm.

Here is Hans’s reply:

While I affirm that God can foreordain fantastically improbable circumstances, I remain agnostic regarding whether evolutionary outcomes actually are fantastically improbable. I continue to think that there are difficulties in calculating evolutionary probabilities. As Van Till has pointed out, such calculations typically require treating organisms as discrete combinatorial objects whose constituent parts are, for quantification purposes, regarded as completely independent of each other. This method, though a bit abstract, at least gives a working number.

However, it’s highly questionable whether that number is truly representative of the chances of an organism’s evolving “in the wild,” since treating the organism as a discrete combinatorial object requires setting aside the various particularities, including natural laws, processes, initial conditions, environmental constraints, selection pressures, and so on, which might bias the development of the organism one way or another.

Adapting Van Till somewhat, it strikes me that you and I are after two different things, Doug. I think Undeniable is asking, “What are the odds that a functionally coherent system would self-assemble, given that any other possible arrangement of its parts is just as likely?” However, given the aforementioned particularities, it’s unlikely that all other possible arrangements are, as statisticians say, “equiprobable.” So, the more relevant (but ultimately unanswerable) question seems to be, “What are the odds this system evolved by natural means, given all natural laws, processes, etc.?” These are very different questions, and I see no reason to assume the answer will be the same in both cases. So, I remain agnostic about probabilities.

Consequently, then, I affirm that God could have wielded “natural forces the way a sculptor wields a chisel” (Axe, 6/22/18) but deny that the theist is limited to choosing between either de novo creation or continual divine intervention. It could be (for all we know) that the probability of life evolving by natural means (given the sum total of natural laws, processes, etc.) might fall on this side of the threshold of fantastic improbability. However, there is obviously more to be said, and I look forward to exploring these themes further as our conversation continues.

Thank you, Hans. Although I’m usually the one holding up the pace of our exchange, I’m enjoying it very much and, like you, I look forward to seeing how it develops.

Your concern that we not overestimate our understanding is good. I certainly agree. On the other hand, we should also be careful not to use the incompleteness of our understanding as an excuse for avoiding truths that don’t really require complete understanding.

A Previous Concession

You conceded previously that we don’t necessarily need precise probability calculations in order to rule out naturalistic explanations, but your continued reservations suggest to me that you may not fully appreciate the staggering disparity between the scale of coincidence that nature can deliver and the scale of coincidence that nature would need to deliver in order for things like dragonflies or dolphins to have come about by natural causes.

A main point of Undeniable is that the making of any whole thing that does something clever requires a great many parts to be arranged in a complementary way. Taken individually, each of these parts is unlikely to be arranged correctly by chance, and this makes the accidental occurrence of the whole thing fantastically unlikely.

Again, crude math is perfectly adequate here. The hundreds or thousands of small fractions representing the individual probabilities inevitably multiply to a probability so small as to constitute an outright impossibility. This makes the conclusion that invention can’t happen by accident extremely robust: it doesn’t depend on the actual values of the small probabilities, provided only that they are indeed small (meaning <0.5).

A Monkey at a Computer

Although biases of the kind you refer to are real, Hans, they don’t alter this conclusion. You’re talking about deviations from perfectly uniform sampling, which is not at all the same as guidance. A monkey playing with a computer keyboard is apt to hit some keys much more than others or to roll its fingers between neighboring keys so as to produce letter combinations that are noticeably non-random. But none of this improves the odds of a sensible paragraph being the end result. In fact, blind biases of this kind are expected to make matters worse, not better!

The sandstorm example leads us to the same conclusion. We don’t need to assume that all shapes that can possibly be imparted to a rugged outcrop of marble are equally probable or that what happens to one patch of surface is independent of what happens to another. In order to be confident that natural processes can’t sculpt this outcrop into something we would mistake for a work of Donatello, all we need to know is that a whole lot of changes would have to happen in a highly complementary way, and none of these changes is apt to happen by chance.

Of course, highly insightful biases in the sandstorm or the evolutionary process could get the respective jobs done, but these fall well outside the naturalistic causes you’ve been limiting yourself to, and unmistakably so. Masterpieces come only from the work of a master.

Image source: Shutterstock, modified by Ryan Axe.