Earlier this year I took part in a pair of lectures at my university—one where I presented on evolution and was critiqued by a colleague who is a supporter of Intelligent Design (ID) and one where my colleague presented on ID and I offered a critique. After both presentations, the audience was invited to ask questions of either of us. One key topic of discussion at both events was that of biological information: what it is, how it works, and whether it is evidence against evolution and for design.
After one of the talks, I had an extended back-and-forth with a member of the audience who held to an ID perspective. As we conversed about biological information, there came a point in the conversation where I realized he was working with a very literal conception of “information” as it pertained to living things—the reason he thought evolution was wrong and ID was correct was because living things contained written codes that could not be explained by natural processes. At this point in the conversation I asked him if he understood that what we were talking about was in fact organic chemistry—complex and intricate organic chemistry, to be sure, but organic chemistry nonetheless. He was taken aback—he had not thought about biological information in that way before.
Part of the problem, of course, is the way biologists themselves like to speak about “biological information”—we speak about the “genetic code” and use words like “transcription” and “translation” as technical terms to describe how information is processed in cells. When we write out DNA sequences, we do not use the chemical structures of the molecules, but rather abbreviate them with the letters “A” “C” “G” and “T”.
In other words, biologists commonly describe biological information with an extended analogy to one of the ways humans use information: language. This approach has its advantages, of course—but that conversation also revealed its drawbacks to me. When biologists use the term “information,” are they describing a process that is analogous to human language or code or something that is a language or code? From the perspective of my conversation partner, it was clearly the latter, based on his understanding of ID arguments.
ID and the Argument from Information
Within the ID community, the “argument from information” is used in two main ways. The first claim is that the ultimate origin of biological information—i.e., the biological information necessary to produce the first life—must be non-material. If indeed what we see in biology is information, so the argument goes, then it must come from a designing mind. In a 2010 interview discussing his book Signature in the Cell, philosopher of science and ID advocate Stephen Meyer makes this point clearly:
The DNA molecule is literally encoding information into alphabetic or digital form. And that’s a hugely significant discovery, because what we know from experience is that information always comes from an intelligence, whether we’re talking about hieroglyphic inscription or a paragraph in a book or a headline in a newspaper. If we trace information back to its source, we always come to a mind, not a material process. So the discovery that DNA codes information in a digital form points decisively back to a prior intelligence. That’s the main argument of the book…
… But there are some lotteries where the odds of winning are so small that no one will win. And that’s the situation of trying to build new proteins or genes from random arrangements of the subunits of those molecules. The amount of information required is so vast that the odds of it ever happening by chance are miniscule. I make the calculations in the book. There’s a point at which chance hypotheses are no longer credible, and we’ve long since gone past that point when we’re talking about the origin of the information necessary for life.
For Meyer, then, the existence of biological information in living things is prima facie evidence that it was designed, and not the result of a material process.
A second claim used within the ID community is that biological information, as we observe it in present-day organisms, is too complex to be the result of evolutionary processes working to assemble it over time. Put another way, even if the original information had been designed at the origin of life, evolution would not have been able to start from this information and go on to produce new genes and new functions through random mutation and natural selection. Meyer puts the argument this way:
In any case, the need for random mutations to generate novel base or amino-acid sequences before natural selection can play a role means that precise quantitative measures of the rarity of genes and proteins within the sequence space of possibilities are highly relevant to assessing the alleged power of mutation-selection mechanism. Indeed, such empirically derived measures of rarity are highly relevant to assessing the alleged plausibility of the mutation-selection mechanism as a means of producing the genetic information necessary to generating a novel protein fold. Moreover, given the empirically based estimates of the rarity (conservatively estimated by Axe at 1 in 1077 and within a similar range by others) the analysis … pose(s) a formidable challenge to those who claim the mutation-natural selection mechanism provides an adequate means for the generation of novel genetic information -- at least, again, in amounts sufficient to generate novel protein folds…
It follows that the neo-Darwinian mechanism -- with its reliance on a random mutational search to generate novel gene sequences -- is not an adequate mechanism to produce the information necessary for even a single new protein fold, let alone a novel animal form, in available evolutionary deep time.
For Meyer, then, the presence of information in living systems, as well as his claim that natural mechanisms such as evolution cannot account for it, form a major part of his case for Intelligent Design. Information must be provided for life to begin and for new genes and proteins to arise.
So is “biological information” merely an analogy of convenience for biologists, or is what we see in the cell information in the sense of a language or code? In the next post in this series, we’ll begin to explore how cellular information processing works as a way to begin addressing this question.