Rosenhouse’s Whoppers: The Environment as a Source of Information.
William A. Dembski
I am responding again to Jason Rosenhouse about his book The Failures of Mathematical Anti-Evolutionism. See my earlier posts here and here.
In Rosenhouse’s book, he claims that “natural selection serves as a conduit for transmitting environmental information into the genomes of organisms.” (p. 215) I addressed this claim briefly in my review, indicating that conservation of information shows it to be incomplete and inadequate, but essentially I referred him to technical work by me and colleagues on the topic. In his reply, he remains, as always, unpersuaded. So let me here give another go at explaining the role of the environment as a source of information for Darwinian evolution. As throughout this response, I’m addressing the unwashed middle.
Darwinian evolution depends on selection, variation, and replication working within an environment. How selection, variation, and replication play out, however, depends on the particulars of the environment. Take a simple example, one that Rosenhouse finds deeply convincing and emblematic for biological evolution, namely, Richard Dawkins’s famous METHINKS IT IS LIKE A WEASEL simulation (pp. 192–194 of Rosenhouse’s book). Dawkins imagines an environment consisting of sequences of 28 letters and spaces, random variations of those letters, and a fitness function that rewards sequences to the degree that they are close to (i.e., share letters with) the target sequence METHINKS IT IS LIKE A WEASEL.
So What’s the Problem?
The problem is not with the letter sequences, their randomization, or even the activity of a fitness function in guiding such an evolutionary process, but the very choice of fitness function. Why did the environment happen to fixate on METHINKS IT IS LIKE A WEASEL and make evolution drive toward that sequence? Why not a totally random sequence? The whole point of this example is to suggest that evolution can produce something design-like (a meaningful phrase, in this case, from Shakespeare’s Hamlet) without the need for actual design. But most fitness functions would evolve toward random sequences of letters and spaces. So what’s the difference maker in the choice of fitness? If you will, what selects the fitness function that then selects for fitness in the evolutionary process? Well, leaving aside some sort of interventional design (and not all design needs to be interventional), it’s got to be the environment.
But that’s the problem. What renders one environment an interesting source of evolutionary change given selection, variation, and replication but others uninteresting? Most environments, in fact, don’t lead to any interesting form of evolution. Consider Sol Spiegelman’s work on the evolution of polynucleotides in a replicase environment. One thing that makes real world biological evolution interesting, assuming it actually happens, is that it increases information in the items that are undergoing evolution. Yet Spiegelman demonstrated that even with selection, variation, and replication in play, information steadily decreased over the course of his experiment. Brian Goodwin, in his summary of Spiegelman’s work, highlights this point (How the Leopard Changed Its Spots, pp. 35–36):
In a classic experiment, Spiegelman in 1967 showed what happens to a molecular replicating system in a test tube, without any cellular organization around it. The replicating molecules (the nucleic acid templates) require an energy source, building blocks (i.e., nucleotide bases), and an enzyme to help the polymerization process that is involved in self-copying of the templates. Then away it goes, making more copies of the specific nucleotide sequences that define the initial templates. But the interesting result was that these initial templates did not stay the same; they were not accurately copied. They got shorter and shorter until they reached the minimal size compatible with the sequence retaining self-copying properties. And as they got shorter, the copying process went faster. So what happened with natural selection in a test tube: the shorter templates that copied themselves faster became more numerous, while the larger ones were gradually eliminated. This looks like Darwinian evolution in a test tube. But the interesting result was that this evolution went one way: toward greater simplicity.
Simple and Yet Profound
At issue here is a simple and yet profound point of logic that continually seems to elude Darwinists as they are urged to come to terms with how it can be that the environment is able to bring about the information that leads to any interesting form of evolution. And just to be clear, what makes evolution interesting is that it purports to build all the nifty biological systems that we see around us. But most forms of evolution, whether in a biology lab or on a computer mainframe, build nothing interesting.
The logical point at issue here is one the philosopher John Stuart Mill described back in the 19th century. He called it the “method of difference” and laid it out in his System of Logic. According to this method, to discover which of a set of circumstances is responsible for an observed difference in outcomes requires identifying a circumstance that is present when the outcome occurs and absent when it doesn’t occur. An immediate corollary of this method is that common circumstances cannot explain a difference in outcomes
So if selection, variation, and replication operating within an environment can produce wildly different types of evolution (information increasing, information decreasing, interesting, uninteresting, engineering like, organismic like, etc.), then something else besides these factors needs to be in play. Conservation of information says that the difference maker is information built into the environment.
In any case, the method of difference shows that such information cannot be reducible to Darwinian processes, which is to say, to selection, variation, and replication (because these are common to all forms of Darwinian evolution). Darwinists, needless to say, don’t like that conclusion. But they are nonetheless stuck with it. The logic is airtight and it means that their theory is fundamentally incomplete. For more on this, see my article with Bob Marks titled “Life’s Conservation Law” (especially section 8).
