Over the past ten months, my friend Hans Vodder and I have been discussing the central claim of my book, Undeniable: How Biology Confirms Our Intuition that Life Is Designed. As the title suggests, the main point is that our intuition that life is the handiwork of a “God-like designer” is spot on.
Although Hans agrees that we should attribute life to God, he sees natural selection acting on random mutations as a plausible way that God might have done his creative work. Reading Undeniable didn’t convince him otherwise, and I’ve been trying to figure out why. He thinks my book’s argument comes up short, whereas I think his preconceptions may have prevented him from seeing the argument. Either way, we hope to carry the conversation on until we come to agreement or until we have a clear understanding of what’s preventing us from agreeing.
One of Hans’s criticisms has been that we would need more accurate calculations of the improbability of life happening by undirected processes in order for this to be ruled out. As he put it in an earlier post: “If… we don’t have enough information to get reasonable evolutionary calculations off the ground, then we aren’t able to say they exceed a particular threshold of improbability…”
I’ve countered this concern by showing that we can know certain outcomes are too improbable to happen by chance without needing anything like accurate probabilities. In the most recent post, I illustrated this by considering the improbability of 500 dropped pennies just happening to land in neat stacks of 50, all heads up. Although we have no way to get an accurate probability here, we know it has to be lower than the probability of all the pennies merely landing heads up. And because we can do the math to show this simpler outcome is far too improbable to happen, we know for sure that the more complex outcome is likewise effectively impossible.
Hans responded as follows:
I actually agree with Undeniable’s “central thesis… that the intuition we all have from childhood that living things are the work of a God-like designer is correct, and that we can know this without technical training,” as you put it. To prevent confusion, however, I’ll say a bit more.
I prefer an approach that philosopher Alvin Plantinga dubbed “design discourse” in Where the Conflict Really Lies. The short version is that design perceptions are assumed to be valid until shown otherwise. So, for me the big question is whether evolutionary biology really shows otherwise.
Here, I think, we part company. Undeniable seems to assume (as many do) that Darwinism, if true, invalidates design. But I’d argue that Darwinism and design are logically compatible with each other. After all, “design” is not a univocal term: there’s always more than one way for God to design something, including ways which might involve natural selection acting upon random mutations.
Notice how this affects our conversation. From my point of view, a design theorist doesn’t actually have to prove design for design beliefs to be rational. Trusting one’s perceptions until she has reason to doubt them is already a rational course of action. And if Darwinism and design are compatible, then evolutionary theory doesn’t automatically invalidate the intuition.
If somebody wants to go further and prove design, great! But the threshold for success in proving design is comparatively higher than it is for simply arguing it’s okay to believe in design even if evolution is true. That’s why I suggested earlier that the argument from functional coherence “should face stricter scrutiny” than the counterflow model. I wasn’t trying to suggest we give evolutionary theory a free pass. I actually agree with you regarding the burden of proof.
I also agree, in principle, that exact probability calculations are not necessarily required to rule out naturalistic explanations. While I’m certainly not a mathematician, I’ll try my best — with fear and trembling! — to indicate where I think Undeniable’s probabilistic arguments fall wide of the mark. I’ll close here, though, with a request for clarification on two points:
1. How might Undeniable accommodate invalid design intuitions?
2. On Undeniable’s account, is functional coherence the exclusive source of design intuitions?
We seem to be making progress here in several respects, Hans, which is encouraging!
I promise not to refuse any of your questions, but if you can bear with me a bit further on this important first thread (where I’m trying to understand your thinking clearly enough to address it directly) I think we will save time in the long run.
After ten iterations, I think I now see how you’re approaching this. Since Darwinism and design are compatible, by your way of thinking, it doesn’t really matter to you whether Darwin’s evolutionary mechanism is scientifically plausible. Consequently, you think we can assume that it is plausible unless someone proves otherwise, and moreover, we have the luxury of maintaining a skeptical stance toward any claimed proof of this kind (since there’s nothing at stake).
If we continue to progress toward understanding each other’s positions clearly, we should return to this question of the relevance of disproving Darwin. Leaving that aside for the moment, I want to continue to press the point that Darwin’s explanation of life has indeed been disproved. That is, we can all be confident that life is designed not just in your broad sense of the term but in the strict sense of being beyond the reach of natural processes. Someone had to make life.
The intent of Undeniable is to show that the same sort of reasoning that convinced us that those 500 pennies can’t land heads up in neat stacks of fifty also tells us that ordinary physical processes can’t create things like hummingbirds or manta rays. In the book, I applied this reasoning to human inventions before showing how it applies to biology, the point being that once you see the direct connection between high-level function and the functional coherence it requires (along with the impossibility of getting this functional coherence by chance) you don’t have to keep running the numbers.
To illustrate the point again, I’ll show how the penny-dropping experiment relates to life.
A Penny for Your Genes
The simplest known free-living organisms have over a thousand protein-coding genes, each with distinct functional roles. More complex forms of life have at least tenfold more. These genes aren’t performing random, disjointed functions. Quite the opposite. Many of them encode the functionally coherent sets of enzymes needed to carry out the chemistry of cellular metabolism. You don’t need a degree in biochemistry to get a sense of the striking sophistication of these reaction networks. Just take a look at this! (Let the full picture load.)
The problem for Darwin’s theory is that within the vast sea of possible arrangements of the DNA bases — the As, Cs, Gs, and Ts — sequences that encode these life-supporting metabolic functions are definitely rare. That’s not controversial, Hans. Based on my experiments, I’ve made the case that genes encoding working enzymes are exceedingly rare within the space of possibilities: 1 in a trillion trillion trillion trillion trillion trillion rare. But you don’t need to accept my figure to conclude that life can’t just happen.
Here’s why. For decades, scientists have been synthesizing random DNA in amounts that exceed what individual cells can carry. Testing these large collections of sequences for encoded functions has been done over and over again, and never has this produced anything that can do the work of a single metabolic enzyme. Not even close. So, whatever you make of my measurements, DNA sequences that encode proteins with metabolic functions are definitely rare in this directly observable sense.
Now, compare this to the penny-dropping experiment. There, the improbability of the stacking aspect (neat stacks of fifty coins) was hard to estimate, but that didn’t matter because a simpler aspect (all heads) was sufficient to show that the desired outcome is impossible. Similarly, to assess the feasibility of natural processes assembling a living cell on a lifeless planet, we can ignore the vast majority of the obstacles (e.g., forming the outer membrane, the nuclear envelope, the cytoskeleton, all the organelles and all the protein complexes… all in their correct locations) by supposing natural processes can enclose whatever molecules happen to be present into membrane compartments of cellular size.
If we further suppose that DNA molecules happen to be among the ones that get enclosed, we can ask how likely it is that each of the several hundred metabolic functions crucial for cellular life would happen to be encoded by the accidental DNA in one of these aspiring cells. In rough but perfectly adequate terms, the answer is: a small fraction raised to a power of several hundred. A small fraction because the experiments have been done on synthetic DNA, without success. A power of several hundred because that’s how many metabolic functions are needed.
There you have it. That’s the end of naturalistic explanations of life, because any small fraction you plug in when raised to such a large power results in a probability far too small for success — on any planet at any time in the history of the universe.
Biology by Groupthink
Interestingly, I’m not aware of any biologist who doubts the staggering improbability of matter accidentally arranging itself into anything resembling earthly life. Rather, the power of groupthink has induced biologists to accept that this seemingly impossible feat was made possible by a long process that delivered huge successes in small increments.
But the brute force of improbability is immune to such tactics. For generations, careful thinkers have recognized this appeal to incremental change as mere sleight of hand — nothing more that concealing the impossibility of the outcome by proposing an impossible process to “explain” it. In other words, the strategy of evolutionary rhetoric has been to make the evolutionary process complicated enough that few can analyze it, and to laugh loudly enough at people who sense the impossibility that they shut up.
As I argue in Undeniable, common-sense reasoning is the best way to call the bluff. No naturalistic account of life can get past this obvious fact:
Any appeal to accidental processes to accomplish an unbelievable coincidence is really just an appeal to unbelievable coincidence.
Source: Evolution Watch