This is in response to a Twitter debate about DNA being proof of god’s existence. SJ Thompson was unable to respond, so she called in an apologist, Sy Garte, who claims a background in biochemistry. Unfortunately, he backed away from debating the issue. Instead he gave an astoundingly poor response on YouTube where he wouldn’t face a direct refutation. You can see it here:
Those who advocate creationism, sometimes under cover of the term “intelligent design”, claim the genetic “code” as evidence, since coded information cannot exist without a coder. This resonates to an extent with the fallacious and long debunked prime mover argument. But as prime mover rests on a faulty cosmological premise and the fallacy of special pleading, the genetic code argument rests on the faulty understanding or intentional misuse of metaphor.
Metaphor is commonly used in science and most other intellectual endeavors as a useful tool for presentation and comprehension. Even the most apt metaphors, however, lack complete mapping to the thing compared and all metaphors break down at some point. In all cases the metaphor is only a comparison to a thing, and not the thing itself. The charmed quark, despite its quirkiness, is not under a magic spell. The Higgs boson, sometimes called the God Particle because it enables other particles to have mass, is not really a divine creator. The big bang was an explosive inflation, but no atmosphere existed to carry sound waves. The Milky Way contains no dairy product. And nucleotides are not letters forming a code, although thinking of them in that way makes description of their function easier to grasp.
Semiotics customarily describes code as a set of symbols operating under a set of rules that stand for another object for the purpose of transmitting information. This entails an encoding process, transmission, and a decoding process. In genetics, nucleotides are assigned a letter and are thought of as information for forming proteins and for self-reproduction. It is a useful way to conceive of the process, but when compared to the definition of code there are also important differences. These differences aren’t problematic insofar as the metaphor is commonly used in biology but can lead to error when stretched beyond that limit.
Creationists like to seize on a literal meaning of code and information to make the argument that nobody has ever encountered encoded information that had no author and therefore, the genetic code must have a creator who designed it. The problem is that claim begins right where the metaphor breaks down and is no longer apt. The nucleotide is not a symbol that stands for something else, but is the thing supposedly stood for. Genes do not encode something that is then transmitted to a decoder. Rather, nucleotides are simply molecules that do what genetic material does –reproduce. They are physical templates of themselves. In addition, they mutate to create new templates – nobody designs them. Instead of encoding, we have four billion years of reproduction, mutation and natural selection. This eliminates the first element of code as referenced above: the encoding process. DNA reproduces and serves as a template for RNA to produce proteins, which is not at all the same as transmitting information but rather a physical act of the material itself. There is no transmission of code, but simply the chemical process. The RNA is not decoding anything but rather is mechanically producing according to a template that itself is the product of mutation and evolution. This is clearly a mechanical molecular process which has no code, encoder or decoder.
The above explanation is what I had proposed to Sy Garte, and to which he chose not to engage. Judging from his responses on the video, it is obvious why he demurred.
1. His first response is “People have been saying for a long time that it is a code”. Sure, but that doesn’t address the issue of metaphor, but only implies that the metaphor has been in use for a long time.
2. “Every textbook says it is a code.” Again, that doesn’t address the issue of it being used as a metaphor. In addition, biology textbooks aren’t the first authority I would consult on issues of semiotics and semantics.
3. He claims that DNA “means something else”. Unfortunately, he fails to tell us what that something else is.
4. “It is the first instance of encoded information in the universe. It is something is something that never occurred before.” Of course, that begs the question of if it is a code at all. Moreover, he must be ignorant of quantum fields, where something like the Higgs field does a similar function to create mass through the Higgs Boson. In neither case is a code involved, but merely a physical process.
5,” We don’t know how DNA was arrived at.” Garte has apparently neglected to keep up with the research. Abiogenesis has shown how precursors to RNA and DNA occur naturally and how they can lead to the formation of nucleotides. There is no need for a creator, and the development of DNA is nothing at all like the writing of a code.
Garte totally evaded addressing the central question of what a code is, but rather lamely responded textbooks say it is a code. He claims to have won debates on this, although he dodged one with me and I see no record of his having done so with others. I would be more than happy to debate this live at his earliest convenience.
5 thoughts on “The Metaphor of Genetic Code”
very interesting subject , great post.
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Sy Garte and I debate this issue on SJ Thomasson’s YouTube Channel
It isn’t a metaphor. There isn’t any evidence that the genetic code is reducible to physics and chemistry. Experimental evidence says the code is arbitrary, in that it is NOT determined by physics or chemistry. Also, DNA is not the genetic code. DNA is just an information carrier. It doesn’t do anything without an existing suite of specialized, specific proteins and a specific coded information processing system. To top it off DNA-based life is impossible without specialized, specific proteins to counter DNA’s instability. DNA has to code for the very proteins that allow it to remain as a viable information carrier. The 2015 Nobel Prize in Chemistry was awarded to the researchers that discovered the instability of DNA and how it is countered.
BTW, DNA doesn’t reproduce. DNA gets reproduced when the cell reproduces. DNA is basically inert.
As Harvard geneticist Richard Lewontin once said: “First, DNA is not self-reproducing, second, it makes nothing and third, organisms are not determined by it” (Lewontin, 1992).