Excursus on the Origin of Life and Evolution of Biological Complexity (Part 23)

Last time I argued that apart from a literal interpretation of Genesis 1 there's just no incompatibility between Genesis 1 and the modern scientific theory of biological evolution. The Scriptures don't say anything about the mechanisms that God might have used to create life or bring about biological complexity, and so it's hard to see how, apart from the Young Earth interpretation, there could be any incompatibility between what the Bible says and modern evolutionary theory.

Some Christians would disagree with this because according to the neo-Darwinian theory of evolution the mutations which serve to drive the evolutionary process forward are random and therefore cannot be designed or occur for a purpose. But this inference involves a fundamental and very important misunderstanding about what evolutionary biologists mean when they use the word "random." When biologists say that the mutations responsible for evolutionary change occur randomly, they do not mean by chance or purposelessly. If they did, then evolutionary theory would be enormously presumptuous, since science is just not in a position to say with any justification that there is no divinely intended direction or goal of the evolutionary process. How could anyone say on the basis of scientific evidence that the whole scheme was not set up by a provident God to arrive at Homo sapiens on planet Earth? How could a scientist know that God did not supernaturally intervene to cause the crucial mutations that led to important evolutionary transitions, for example, the reptile-to-bird transition? Indeed, given divine middle knowledge, not even such supernatural interventions are necessary in order for God to guide the evolutionary process, for God could have known that if certain initial conditions were in place, then given the laws of nature certain life forms would evolve through random mutation and natural selection, and so he put such initial conditions and laws in place knowing that life would evolve from them.

Obviously, science is in no position whatsoever to say justifiably that the evolutionary process was not under the providential direction of a God endowed with middle knowledge who determined to create biological complexity by means of random mutation and natural selection. So if the evolutionary biologist were using the word "random" to mean “undesigned” or “purposeless” or “unguided,” then evolutionary theory would be philosophy, not science. But the evolutionary biologist is not using the word “random” in that sense. This fact, which is ignored by both critics of theistic evolution as well as apologists for naturalistic evolution, became very clear to me in the course of my preparation for my debate with the eminent evolutionary biologist Francisco Ayala on the viability of intelligent design in biology.[1] According to Ayala, when evolutionary biologists say that the mutations that lead to evolutionary development are random, they do not mean occurring by chance; rather they mean irrespective of their usefulness to the organism. They mean that these mutations occur irrespective of their usefulness to the host organism. This is hugely significant. The scientist is not, despite the impression given by partisans on both sides of the divide, making the presumptuous philosophical claim that biological mutations occur by chance and, hence, the evolutionary process is undirected or purposeless. Rather, he means that the mutations do not occur for the benefit of the host organism. If we take "random" to mean irrespective of their usefulness to the organism, then randomness is not incompatible with direction or purpose.

Alvin Plantinga has made this same point in his book Where the Conflict Really Lies. According to Plantinga there is not even a superficial conflict between evolutionary biology and theism. Plantinga chastises scientists who have recklessly asserted that according to evolutionary biology the evolutionary process is undirected or purposeless or unguided. Such claims are not, he says, properly part of the biological theory itself; rather, they are what he calls a philosophical add-on, that is to say, an extra-scientific assertion. In support of this point, Plantinga quotes the prominent evolutionary biologist Ernst Mayr, who says the following, “When it is said that mutation or variation is random, the statement simply means that there is no correlation between the production of new genotypes and the adaptational needs of an organism in a given environment.”[2] There isn't any correlation between the mutations and the needs of the host organism to adapt to its environment. That's the same definition as given by Ayala – that they occur irrespective of their benefit to the host organism. Such a definition of "random" is wholly compatible with God's willing or even causing mutations to occur with a certain end in view.

Let me give an example. Suppose that God in his providence causes a mutation to occur in an organism, not for the benefit of that organism but for some other reason. For example, maybe it will produce easy prey for other organisms that God wants to flourish, or maybe because he knows that it will eventually become a fossil that Jones will someday discover, which stimulates Jones' interest in paleontology, so that he embarks upon the career which God had in mind for him. In such a case the mutation is both purposeful and random.

So unless we adopt a literal interpretation of Genesis 1, there is no conflict between the Bible and standard evolutionary biology. What that means is that the Christian therefore is free to follow the evidence where it leads. In this respect the Christian actually enjoys an advantage over the atheist. As Plantinga has put it, for the atheist evolution is the only game in town. Thus the naturalistic biologist Richard Lewontin has admitted,

We take the side of science in spite of the patent absurdity of some of its constructs, in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment, a commitment to materialism. It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counterintuitive, no matter how mystifying to the uninitiated.[3]

So, as Plantinga says, for the materialist (for the naturalist) evolution is the only game in town, no matter what the evidence, no matter how improbable the results. But the Christian is not so restricted, and so he can actually be more open-minded and more objective than the atheist in following the evidence where it leads.