Is Evolution a Purposeless Mechanism?

We’ve come a long way through this series, and at last we’ve come to the end of the scientific material that we’ll cover. If you’ve made it this far, congratulations! Hopefully you’ve deepened your knowledge of evolution along the way.

Of course, the scientific details of evolution are not the only issue of interest for Christians. In fact, it seldom is the pressing one for evangelicals. Rather, it is the theological issues that predominate conversations about evolution – primarily, whether an evolutionary understanding of creation is compatible with orthodox Christian faith. And so, it would be remiss for us not to discuss such issues explicitly in this series, at least in brief.

Of course, in so doing I am painfully aware that theology is not my area of expertise. My colleague Ard Louis puts it well when he describes the limited scope of the typical academic:

When I was a child growing up in central Africa, I didn’t come across too many PhDs. I assumed that someone with Dr. in front of their name would surely know nearly all there is to know about their subject and a great deal more about the rest of the world of academic thought. I’ve now got one myself and supervised and examined a good number of PhD theses in both physics and chemistry. It has certainly disabused me of the idea that I or for that matter most people with PhDs know a great deal about anything beyond the very narrow confines of our (sub)specialties.

So, what I offer here should not be considered, by any stretch, to be the definitive word on the subject. Rather, my thoughts here are a layman’s approach to what is a complicated subject.

Is evolution “random”?

One of the primary concerns about evolution that I encounter is the question of “randomness” – by which most folks mean something to the effect that evolution is an unpredictable, uncontrolled process – that as such could not be used by God as a purposeful mechanism to bring about his aims. There are, of course, usually some scientific misunderstandings lurking under the question. As we have seen, while evolution has some stochastic, contingent features (such as mutation), evolution as a whole is not a “random” process in the sense usually intended by concerned Christians. Even with its stochastic features, it also exhibits at least a degree of repeatability, as we have seen in recent posts on convergence. While the contingency of evolution may move a Stephen J. Gould to see purposelessness, the convergence of evolution may also move a Simon Conway Morris to see an elegant, purposeful mechanism.

A microcosm of randomness and convergence – antibody formation

Perhaps an analogy will help. Every other fall semester I teach a course on immunology – a subject that is as daunting to students as it is fascinating. Stochastic processes are a key feature of the human immune system – in fact, without them, we would be poorly equipped to fight off infection. The challenge for any immune system is the need to fight off an effectively infinite pool of pathogens, but to do so with limited genetic resources. Put another way, we have only about 20,000 genes in our genomes – and the vast majority of those have to do essential tasks other than fight off disease. Pathogens, on the other hand, are legion. Even if bacteria, viruses, and other pathogens were unable to evolve, we still would face a dizzying array of them. Throw their own evolution into the mix, and we’re faced with overwhelming diversity.

The way we fight off that diversity with a comparative handful of genes is through randomizing them. Antibodies, which bind on to pathogens and target them for destruction, are heavily randomized in the areas that do the sticking – but not randomized in their other sections. The randomizing is accomplished by mixing and matching a large (but finite) set of smaller components to form a final antibody protein – and each cell that produces antibodies does the mixing and matching (which occurs at the DNA level) differently. During the mixing and matching that randomizes the antibody gene DNA in these cells, random mutations are introduced in the joints between the components as they are assembled. The result is a dizzying array of antibodies from a comparatively small gene set – a dizzying diversity adequate to match (and beat) the pathogens at their own game.

Just like with evolution, antibody production also has a selection step. The diversity of antibodies we produce is truly staggering – but only a tiny fraction will ever be used (the ones that, through chance, bind on to a pathogen that invades us). This process might seem wasteful – we make vastly more antibodies than we will ever use – but without it, the system would not protect us.

From the perspective of an antibody that is selected for, however, the process is perfectly tuned to meet the desired goal – an antibody that binds tightly to its pathogen target. Now, the precise path to arrive at the goal is not certain – scientists cannot predict in advance that any specific antibody structure will arise during an immune response. They can predict, however, with absolute confidence that many antibodies that do bind tightly will be produced, and through varied routes. Randomness, plus selection equals convergence in this case – and we can be sure of it.

Musing about evolution and divine action

I tend to view evolution largely in the same way I view antibody formation. It’s not a perfect analogy, of course – all analogies break down eventually. What I see in antibody formation, however, is that randomness can easily play a part in an overall process intended to produce a desired outcome. And, as one might expect, I agree with Simon Conway Morris that convergence is a powerful force that shapes evolutionary history in powerful ways – in ways that largely offset, but do not completely eliminate, the effects of chance.

The question then remains, of course, whether what we perceive as “random chance” – the mutations of evolution or the shuffling and mutations of antibody formation – are in fact “random” to God. Does God foreordain every mutation in the immune system? Every mutation along the way as our own species became human? The conversation in the church foyer usually wends its way through this issue sooner or later. Some believers hold strongly that nothing is random (in the sense of being unknown or unpredictable by God). Others take a different view – that God’s sovereignty is not accomplished through rigid determinism, but rather that God permits creation a measure of freedom, within set boundaries, to act in stochastic ways that nonetheless accomplish his overall purpose.

To me, it seems that God is comfortable working through what we might consider a needlessly circuitous and inefficient path to achieve his aims (as the Old Testament readily attests to – even as a child I recall wondering why God just didn’t do things more quickly and directly). So, what appears to me to be wasteful and inefficient may in fact have a purpose. Of course the incarnation is the ultimate example of this – God in human form, living as a first-century peasant, suffering a death reserved for insurrectionists – that somehow, amazingly, turns out to have been the goal – the telos – all along. For Peter, the idea of a crucified messiah as God’s plan made absolutely no sense in human terms. For Peter, and later Paul, the resurrection was God’s vindicating stamp of approval on Jesus and his life – his life and death that Paul had, to that point, rejected as a failure. It’s not for nothing that Paul talks about God’s wisdom as foolishness to the world.

So, even though I lack certainty on how God uses what we perceive as stochastic processes, I am certain of this – I have confidence that God uses them in a way that does not interfere with his sovereignty, just as human free will does not (somehow) interfere with his sovereignty. Scripture is abundantly clear that the entire cosmos is under the sovereign rule of God, and in that I find rest, even as I explore and ponder the details – details that I doubt we will settle this side of glory.

In the next post in this series, we’ll tackle a second common question about evolution and Christianity – how an evolutionary creationist might approach the question of humans being created in the image of God.