Since I am still getting caught up on my blog reading after my trip to the big conference, I have only just noticed Jeffrey Shallit’s interesting post on information theory. He writes:

Creationists think information theory poses a serious challenge to modern evolutionary biology — but that only goes to show that creationists are as ignorant of information theory as they are of biology.

Whenever a creationist brings up this argument, insist that they answer the following five questions. All five questions are based on the Kolmogorov interpretation of information theory. I like this version of information theory because (a) it does not depend on any hypothesized probability distribution (a frequent refuge of scoundrels) (b) the answers about how information can change when a string is changed are unambiguous and agreed upon by all mathematicians, allowing less wiggle room to weasel out of the inevitable conclusions, and (c) it applies to discrete strings of symbols and hence corresponds well with DNA.

All five questions are completely elementary, and I ask these questions in an introduction to the theory of Kolmogorov information for undergraduates at Waterloo. My undergraduates can nearly always answer these questions correctly, but creationists usually cannot.

The questions? Well, you’ll just have to link on over to Jeffrey’s blog for those.

He is right, of course, about creationists not really understanding the mathematical and scientific machinery they throw around. I have seen more than one creationist pontificate about how genetic mutations always lead to a decrease in information, without ever bothering to say how they propose to measure information in the first place. They do not seem to grant that if a point mutation from *x* to *y* leads to a loss of information, then the reverse mutation from *y* back to *x* would have to increase information.

The reason is not hard to spot. They are not really interested in applying the often complex machinery of modern mathematical information theory to the problem of understaning evolution. It is just jargon to them, useful for making dopey, Gee Whiz!, style arguments sound scientifically rigorous.

They treat thermodynamics the same way. They might blather about entropy and the second law, but in the end they are not really using any of the machinery of the subject. They are not evaluating any integrals, or calculating the change in entropy in going from one state to another, or describing reversible processes that model some biological phenomenon.

Likewise for probability theory. They are forever assigning small numbers to physical objects or processes and then, by multiplying the small numbers together, producing smaller numbers still. These smaller numbers are said to represent the probability of a whole sequence of events happening one after the other. I know from experience they have no interest in trivial details, like establishing the independence of the events whose probabilities are being multiplied.

Mathematicians and physicists have worked very hard to produce useful systems of abstract machinery. Probability theory, information theory and thermodynamics are fantastically useful, but it can be difficult to master their subtleties. The fact is that we have copious evidence from various branches of biology and geology that biological evolution has occurred, and that natural selection has a big role to play in the process. If some abstract mathematical model says otherwise, then so much the worse for the model.