Hunter, Part 2
I now continue with my analysis of Cornelius Hunter's contribution to William Dembski's anthology, Uncommon Dissent.
In the first part of this series I analyzed Hunter's arguments about the fossil record. I pointed out that his entire argument collapses because he conflated two different questions: “Is the history of life as revealed in the fossil record consistent with evolution?” on the one hand, with “Can we determine specific lines of descent from the fossil record?” on the other.
Another place where Hunter gets things badly wrong is in his discussion of the universal genetic code. He writes:
The DNA code is routinely used as strong evidence for evolution, but why? Everyone knows that one cannot use a code without having a method for encoding and decoding the information that is being transmitted. And, of course, the sender and receiver must be using the same code for the system to work. Volumes have been written on the cellular machinery that is involved in nature's scheme for using the DNA code, and we still don't understand all the details. It is phenomenally complex and it is not easily explained as a product of Darwin's evolutionary process. (P. 208)
Let's take this one sentence at a time:
- The DNA code is routinely used as strong evidence for evolution, but why? Actually, the universality of the DNA code, and the universality of the cellular machinery used to translate that code, are evidence for a universal common ancestor. If these universals were not present it would be essentially impossible to argue that any two modern species share a common ancestor somewhere in the past.
- Everyone knows that one cannot use a code without having a method for encoding and decoding the information that is being transmitted. I have no idea what the point of this sentence is. What does this have to do with whether different species use different codes, or have different cellular tools for encoding and decoding?
- And, of course, the sender and receiver must be using the same code for the system to work. The “sender”, and “receiver” in this analogy are the parents and offspring of a given species. So, yes, the offspring must be using the same genetic code and possess the same cellular machinery as the parents. Again, what does that have to do with whether these are different codes in use in different species?
- Volumes have been written on the cellular machinery that is involved in nature's scheme for using the DNA code, and we still don't understand all the details. Well, at least we agree on something.
- It is phenomenally complex and it is not easily explained as a product of Darwin's evolutionary process. And here we have the standard conflation of evolution with the origin of life. Evolutionary theory has nothing to say one way or the other about the origin of the code. The code is simply taken as a given. Evolution also does not explain the motions of the planets around the Sun, but no one thinks that's a legitimate objection to Darwin's theory.
But Hunter disputes the idea that evolution predicts a universal code. Picking up from where the last quote left off we find:
Furthermore, evolution does not predict there to be a universal DNA code. A number of explanations of the code's supposed evolution are currently under consideration. In one way or another, the code is supposed to have evolved from simpler codes; but if the code could have evolved over time, then it is easily conceivable that it could have evolved into several different codes. In other words, evolutionary theory could explain the existence of multiple codes in nature. As such, evolution does not require there to be a single DNA code. (P. 208)
Evolution does not require a single code, but universal common ancestry does. In principle life could have formed several times on Earth, with each origination event producing a different code. After these events life could have evolved by the standard mechanisms. As a hypothetical scenario this is fine.
But such a scenario would be hard to square with the patterns of descent suggested by all the various anatomical homologies that we find, and it is hard to square with the fossil record. In other words, we have copious evidence from fossils and homologies that there is a universal common ancestor for all life. If it then turned out that there were multiple genetic codes, each one leading to a different evolutionary experiment, we would have some serious dissonance in the data. So it is comforting that the code is, in fact universal.
Let's go a little bit further. Picking up where the last quote left off:
The universal genetic code doesn't seem like a good candidate to serve as strong evidence for evolution. Evolution has trouble explaining how the code and its attendant machinery came about, and evolution does not require there to be a single code. How then does the universal genetic code support evolution so strongly? The answer is that evolutionists believe that if the species had been created independently, they would not share the same code. (P. 208-209)
Here Hunter makes explicit the error of conflating evolution with the origin of life. And we have already discussed what evolution expects about a universal code. I would like to examine that last sentence, however.
Hunter includes a footnote to back up his assertion about special creation predicting that the code should not be universal. He refers us to Mark Ridley's textbook Evolution. Sadly, Hunter's footnote refers us to the first edition of the book, whereas I only have the second edition. So I will leave open the possibility that Ridley says something different in the first edition.
But in the second edition Ridley does not say anything remotely like what Hunter attributes to him. Ridley does discuss the relevance of the universal genetic code, but he does so in terms that are similar to what I have provided here. I'd be surprised if you could find a single scientist making the argument Hunter describes above.
The simple fact is that scientists to not defend evolution by speculating about what an intelligent designer would do and then showing that these expectations are not met. Scientists do sometimes argue this way when they are criticizing creationism, however. That is entirely reasonable. Creationists believe that God has certain attributes such as omnipotence and omnibenevolence, and it is natural to ask how those characteristics would be reflected in the creation.
Criticizing creationism is not the same as defending evolution, though most creationists fail to see the distinction.
The relevance of the fossil record to assessing the validity of evolution, and the significance of the univeral genetic code are not hard to grasp. Hunter, nonetheless, seems not to have grasped them.