Evolution and the Origin of Biological Information, Part 1: Intelligent Design
One prominent antievolutionary argument put forward by the Intelligent Design Movement (IDM) is that significant amounts of biological information cannot be created through evolutionary mechanisms – processes such as random mutation and natural selection. ID proponent and structural biologist Doug Axe frames the argument this way (his comments begin at approx. 15:19 in the video):
“Basically every gene, every new protein fold… there is nothing of significance that we can show [that] can be had in that gradualistic way. It’s all a mirage. None of it happens that way.”
The importance of this line of argumentation for the IDM can be seen clearly in Stephen Meyer’s book Signature in the Cell (published in 2009). In this book, Meyer claims that an intelligent agent is responsible for the information we observe in DNA because, in his words, natural mechanisms “will not suffice” to explain it:
Since the case for intelligent design as the best explanation for the origin of biological information necessary to build novel forms of life depends, in part, upon the claim that functional (information-rich) genes and proteins cannot be explained by random mutation and natural selection, this design hypothesis implies that selection and mutation will not suffice to produce genetic information … (p. 495)
It’s hard to overstate the importance of this argument for Meyer in Signature, and for the IDM as a whole. In the conclusion to a pivotal chapter entitled “The Best Explanation” Meyer presents the following summary of his case:
Since the intelligent-design hypothesis meets both the causal-adequacy and causal-existence criteria of a best explanation, and since no other competing explanation meets these conditions as well –or at all–it follows that the design hypothesis provides the best, most causally adequate explanation of the origin of the information necessary to produce the first life on earth. Indeed, our uniform experience affirms that specified information … always arises from an intelligent source, from a mind, and not a strictly material process. So the discovery of the specified digital information in the DNA molecule provides strong grounds for inferring that intelligence played a role in the origin of DNA. Indeed, whenever we find specified information and we know the causal story of how that information arose, we always find that it arose from an intelligent source. It follows that the best, most causally adequate explanation for the origin of the specified, digitally encoded information in DNA is that it too had an intelligent source. (p. 347)
Put more simply, Meyer claims that if we see specified information, we infer design, since we know of no mechanism that can produce specified information through an unintelligent, natural process. As a logical argument, Meyer’s position only works if (and this is a big if) – his premises are correct.
The issue is that Meyer’s case is open to refutation by counterexample, and even one counterexample would suffice. If any natural mechanism can be shown to produce “functional, information-rich genes and proteins”, then intelligent design is no longer the best explanation for the origin of information we observe in DNA, by Meyer’s own stated criteria. His entire (500+ page) argument would simply unravel.
The obvious problem for Meyer’s case is that biologists are well aware of a natural mechanism that does add functional, specified information to DNA sequences (and in some cases, creates new genes de novo): natural selection acting on genetic variation produced through random mutation. Not only are biologists aware of some examples of natural selection adding functional information to DNA, this effect has been observed time and again, and in some cases it has documented in exquisite detail. When I reviewed Signature for the American Scientific Affiliation journal Perspectives on Science and Christian Faith (PSCF) what struck me, repeatedly, was that Meyer made no mention of the evidence for natural selection as a mechanism to increase biological information. I fully expected him to dispute the evidence, certainly – but the surprise for me was that he simply denied it to be sufficient without addressing any evidence. The closest Meyer comes in addressing natural selection in Signature is in a section discussing evolutionary algorithms used to simulate evolution. As I said in my review:
Meyer’s denial of random mutation and natural selection as an information generator notwithstanding, in a discussion about evolutionary computer simulations, Meyer makes the following claim:
If computer simulations demonstrate anything, they subtly demonstrate the need for an intelligent agent to elect some options and exclude others- that is, to create information.
Employing this argument, Meyer claims that any mechanism that prefers one variant over another creates information. As such, the ample experimental evidence for natural selection as a mechanism to favor certain variants over others certainly qualifies as such a generator. Meyer, however, makes no mention of the evidence for natural selection in the book.(pp. 278-279)
In the PSCF review I went on to point out a few examples of known instances in biology where random mutation and natural selection have indeed led to substantial increases in biological information, but the limitations of space in that format precluded me from exploring those examples in more detail, or from presenting that information at a level readily accessible to non-specialists. In this series of posts I will attempt to remedy that shortcoming by exploring several examples in depth. The question of how new specified information arises in DNA, far from being an “enigma”, is one of great interest to biologists. While the IDM avoids this evidence to present a flawed argument for design, responding to this flawed argument provides an excellent opportunity to discuss some particularly elegant experiments in this area.
Of course, it should be noted that describing how specified information can arise through natural means does not in any way imply God’s absence from the process. After all, natural processes are equally a manifestation of God’s activity as what one would call supernatural events. So-called “natural” laws are what Christians understand to be a description of the ongoing, regular and repeatable activity of God. As such, the dichotomy presented in ID writings of “naturalism” versus theism is a false one: is not God the Author of nature, after all?
In the next post in this series, we will examine an ongoing experiment over twenty years in the making: the Long Term Evolution Experiment (LTEE) on E. Coli conducted in the laboratory of Richard Lenski at Michigan State University.
Dennis Venema is Fellow of Biology for The BioLogos Foundation and associate professor of biology at Trinity Western University in Langley, British Columbia. His research is focused on the genetics of pattern formation and signalling.