Thursday, July 7, 2011

The Discovery Institute and Basic Math

I know, I haven't been around much. Work has been more than a little too busy. But I have been reading and trying to keep up. Well this little one popped up and I can't resist. So here goes:

What caught my eye was a post over on the so-called DI news site: "Fewer Mutations Means More Time". Since I always thought that the DI argued about any possible beneficial mutation, but maybe I was wrong on that count. I know they have frequently tried to play the odds argument, that is how the odds are much to long for any mutation to form a useful characteristic. Well anyway, this post links over to a new study Nature Genetics that says there might be fewer mutations between human generations than previously thought. So how does the DI spin it?

Here is the paragraph that just cracked me up:


There's another issue that has not been fully addressed. These 60 mutations per generation are very few mutations for natural selection to work with. But humans have a very long generational time. And finally the authors reported that most of these mutations, particularly in the family with the higher mutation rate, occur in the non-coding part of the DNA. Finally, from what we know about mutations that do occur and have a noticeable effect on the person, they are often deleterious or serve to remove some type of function. Rarely are they beneficial and rarely do they add function. The question is, is this really enough mutations and enough time for natural selection to produce novel body plans?
The way this reads is that there are ONLY 60 mutations per generation -- human generations. Doesn't the study say 30-60 per individual? So we have millions of children born each day -- each one of them with between 30 and 60 mutations from their parents. Why are these too few for Natural Selection to work with? We are talking about millions of mutations every single day! It's not like all the kids born on the same day have identical mutations, or that all the kids in a generation all have the same set of mutations. This looks like . . . well to me . . . that the DI is doing a little numeric sleight-of-hand and making it sound much different than it really is.

The other part that I find funny is how closely the DI tries to tie the study to what they claim about mutations. Here, read these lines again:


"And finally the authors reported that most of these mutations, particularly in the family with the higher mutation rate, occur in the non-coding part of the DNA. Finally, from what we know about mutations that do occur and have a noticeable effect on the person, they are often deleterious or serve to remove some type of function. Rarely are they beneficial and rarely do they add function." (I added the emphasis)
Who knows this? Isn't this claim that the DI has often repeated, but never substantiated. I recall posted by Olivia Judson discussing mutations and I believe the majority of mutations were benign when it comes to Natural Selection, that is they do not offer an advantage or disadvantage in survival or reproductive opportunity. So it appears the DI is pushing their own unsubstantiated ideas as if they were factual -- in other words typical DI behavior.

1 comment:

rubble said...

Welcome back, Ted.

The DI messed up big time here. In their rush to "disprove" generally accepted evolutionary processes, they commit elementary reading comprehension errors. This is what happens when ideology drives "science reporting."

The relative harm of mutations is also over-emphasized, as you correctly point out. For example, point mutations, where a single nucleotide is substituted with another, often result in identical amino acid coding, because there are generally several different nucleotide codons for a given amino acid. Such synonymy occurs in roughly 25-30% of all point mutations, if I recall my calculations correctly.