Larry Moran Responds Regarding Directed Mutations
|August 16, 2012||Posted by johnnyb under Intelligent Design|
In a previous post, I had taken Dr. Larry Moran to task about whether or not mutations, as they exist in nature, are random. Dr. Moran has responded, so I thought I’d give readers a summary of his response.
Dr. Moran seems to have at least two different things in mind when he says that evolution is unguided. That’s not a problem per se, but it is always good to be precise about which concept of unguided-ness we are discussing.
- The appearance of homo sapiens was not an intended part of the evolutionary process
- Mutations are random with respect to their ultimate usefulness
In my post, I was primarily concerned with #2, as I will be in this one.
Presumably, he has several different ways of knowing whether or not mutations are random. However, he only lists one: “Comparing the sequences of homologous genes in different species” Unfortunately, he didn’t say what it was about the sequences of homologous genes in different species that led to his conclusion that mutations are random. Maybe he will help us out with that one later.
However, unfortunately, he totally misses the point of my post. Dr. Moran said that creationists (meaning me) misunderstand his meaning of randomness. However, as we will see, I am precisely using the exact same definition of randomness that Moran is. But first, let’s see what Dr. Moran has to say:
Creationists also like to argue that mutations are not truly random. They point out that there are mutational hotspots in the genome and there’s a bias in favor of some mutations over other (e.g. transitions are more common than transversions). In most genomes, mutations are more common at sites where C is methylated.
All this is true and the results were discovered by scientists, not creationists. It’s why scientists try to avoid saying that mutations are random; instead they say that mutations are random with respect to their ultimate usefulness. Sometimes we slip up for simplicity as when I said in my previous posting that mutations are “essentially random,” although I added “Let’s not get into quibbling about the meaning of “random.”
What Moran is attempting to do is to paint my argument as saying, “because mutations don’t follow a uniform random distribution, the random mutation hypothesis is false”. But that wasn’t ever my argument at all. I was arguing specifically against what Moran says the true definition of evolutionary randomness is – “random with respect to their ultimate usefulness”.
In other words, it is not interesting to me that the mutations that occur when an antigen invades is restricted to a specific region of the genome. What is interesting is that the specific region of the genome that mutations get restricted to when an antigen arrives is the PRECISE region of the genome that the organism needs for its utility. I hope you can see the difference between those two ideas. In the former case, we simply are talking about a non-uniform distribution. That is uninteresting. What is interesting is the specific way it is non-uniform. It is biased precisely in the direction of contributing to the ultimate utility of the organism!
Moran goes on to give some details as to the mechanistic basis of this targeting, which are of course interesting. He misses one important one – an intron targets the precise location of the mutations – moving the intron will change the position of the mutation region and cause improper mutations to occur. But that is really beside the point.
The big question is, are mutations random with respect to their ultimate usefulness? In this particular case, the answer is a resounding no. I would argue that the answer continues to be no in more and more mutational mechanisms. Keep in mind that no experiments are required in order for an evolutionist to proclaim that a given mutation is random – this is simply assumed to be the case. But it can sometimes take 10 or more expensive experiments to demonstrate a mutability mechanism, such as this one. Therefore, since evolutionary biologists are not predisposed to think that mutations are directed, and it costs lots of time and money to prove that a mutation is associated with a purposive mechanism, it is not surprising that it often takes many years after the discovery of a mutation to learn about the mutational mechanism behind it. But more and more that is what we are learning.
UPDATE – I thought that if anyone is interested in a more full discussion of randomness and its intersection with design theory, you might be interested in a previous paper of mine on the subject.