Tuesday, February 10, 2009

Information Theory

The past few days I've been reading and re-reading articles and books about Information Theory. William Dembski has been working with Robert J. Marks II on various aspects of Information Theory and their pertinent website is The Evolutionary Informatics Lab. They have several papers listed under their Publications link. I read one of them which is to be published soon called, "Conservation of Information in Search." It addresses, for one thing, the use of computers to "prove" evolution by programs which pick out some final answer when a random search is used. They describe how the information in these programs is "partitioned" so that each part of the the programmed answer, such as a letter in a sentence, will stay in its place when it turns up in the random search. The outcome in these cases is dependent on information fed to the computer program.

The "father" of Information Theory is considered to be Claude Shannon. He used statistical information about language to improve methods of communications. I can follow a lot of the explanations, and some of it is easy to understand, but other parts are complicated. The link to Information Theory in Wikipedia has some mathematical explanations and other references for those of you who are interested and mathematically-minded.


Another man, physicist Hubert Yockey, applied Information Theory to biological systems. I've re-read some of his papers from the 1970's and 1980's. One of them is "A Calculation of the Probability of Spontaneous Biogenesis by Information Theory," from the Journal of Theoretical Biology (1977) 67, 377-398. (I was unable to find it on the Internet and got this and other articles by him through inter-library loan). He used data previously worked out by Grantham in 1974 on a particular molecule in most species called cytochrome c. He compared 101 amino acids which make up cytochrome c in the categories of composition, volume and polarity (electric charges). Yockey worked on the number of molecules which could function as cytochrome c compared to the number of molecules that couldn't, using the 20 amino acids that make up protein. Though he found a tremendous number that could function as cytochrome c (about 4 x 10^61), the probability that the 20 amino acids would form any of them by chance is only about 1 in 10^65 (10^65 being a 1 with 65 zero's after it).

Yockey refutes the prevailing theories of evolutionary pre-life formation by showing how improbable are the events that would lead from random molecules to formation of functional proteins and/or genomes. His calculations eliminate even the possibility of life forming at any time in the universe on any available planet. It is interesting how these pre-life theories persist even today.

One personal note: it's my husband's birthday. Happy birthday, Tom, and may you have many more!!

Also, Thursday is Lincoln's birthday and Washington's is to come soon. Tom and I watched several shows on slavery and the Civil Rights movement Sunday on PBS. It was interesting how the former slaves adjusted to freedom very soon after the end of the civil war. They became a part of government very quickly, but then were attacked by the persons who remained prejudice and unwilling to follow the new laws. The African-Americans were again oppressed. If Lincoln had lived longer, perhaps permanent changes for the good would not have taken so long.

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