Wednesday, April 8, 2009

Intelligent design and the myth of irreducible complexity

The creationist movement around the world has grown in strength and number over the last half century or so, particularly in places with a high degree of cultural diversity and poor educational standards such as the Bible belt of the American south and mid-west. The creationist movement shouldn't pose a problem for anyone because of their beliefs. There are groups out there with far stranger views of the world than creationists. It's only when creationists decided to try and prove their faith that the scientific community and latterly the world at large began to sit up and pay attention. The idea of proving one's faith is rather paradoxical as demonstrated in The Hitchhikers Guide to the Galaxy:

"The argument goes something like this. I refuse to prove I exist says God for proof denies faith and without faith I am nothing. But says man, the babelfish is a dead giveaway isn't it. It proves you exist and so therefore you don't. Q.E.D. Oh, dear I hadn't thought of that says God and promptly vanishes in a puff of logic."

The attempt to teach creation science in the classroom began in the sixties with the publication of "The Genesis Flood" where Henry Morris and John Whitcomb argued for a literal interpretation of the genesis creation story. Their argument focused on proving that the earth could be created in six literal days, that humans and dinosaurs co-existed and that each species was specifically created by God (which would be some achievement it has to be said since approximately 99% of all the species that have ever existed are now extinct). These guys gained a newfound popularity among conservative Christians in America and were quickly established on the lecture circuit with Morris going on to found the Institute for Creation Research. The creation science movement grew steadily until it received two major hammer-blows in the eighties. The first was in 1982 when the Mc. Lean v. Arkansas case saw the court ruling that the proposed "Balanced Treatment for Creation-Science and Evolution-Science Act" was unconstitutional. Then in 1987 the Louisiana Supreme Court ruled that the same law which was shot down in Arkansas but passed by the Louisiana legislature was unconstitutional. Creationists soon realised that a change of tactics was needed.
This change came about in the late 1980s as a result of the Louisiana ruling. In 1989 a biology textbook called Of Pandas and People emerged which put forth the arguments of the scientific theory of intelligent design. This pseudoscientific garbage claims that there is a significant amount of scientific evidence which shows that life on earth could not have reached this point without having been designed by a supernatural creator. The champion of this cause has been Michael Behe, a lecturer in biochemistry at Lehigh University, and his pet project of irreducible complexity.
The first time I heard of the idea of irreducible complexity, that is the idea that there are creatures alive today whose biological structure is so complex that it had to have been designed, it seemed immediately ludricous. A further explanation of the argument is that it is claimed that the action of evolution which involves incremental changes to an organism cannot explain the development of higher order structures such as flagellates where every component of the structure needs to be together in order for the creature to function. This idea seemed even more ridiculous than the simple explanation. It seemed to me that these so-called scientists had completely misinterpreted natural selection either accidentally or deliberately.
The problem lies in the interpretation of how natural selection effects incremental changes in an organism. The intelligent design advocates believe that evolution has the effect of adding bits on to a creature one piece at a time until you get a working creature. This is shown most clearly in Behe's book "Darwin's Black Box". In this book, Behe argues that bacterial flagella consist of 10 different biological components, all of which must be in place and functioning for the flagellum to work. Firstly, as biologist Kenneth Miller proved, the flagellum can continue to perform the same function with as little as four components. Secondly, Behe's argument that if you take one component away the organism stops functioning seems to completely miss the point. A modern car for example won't work in the way that it should if you take away the engine or the steering wheel or the gearbox. Yet the modern car wasn't designed piece by piece, adding bits on until you ended up with a functioning vehicle. Rather it evolved from simple horse or even ox drawn carts through stagecoaches and wagons to early vehicles like the Model T to the cars we drive today. In the same way evolution updates an organism not by adding new bits on in the way Behe claims but by constant revisions of the entire organism. In order to demonstrate this idea it is necessary to set up a little thought experiment.
Back in the 1850s when Charles Darwin was formulating his theory of evolution, he was influenced not only by the things he saw on his travels but also by the prevailing theories of the time. One in particular has had a long lasting impact on biological and anthropological research. That is of course the concept of division of labour put forward by economist Adam Smith. Although Smith was referring to economic principles of society the same holds true for evolutionary development.
Imagine the following scenario, you have five people stranded on a desert island for years (think Lost). Now this island is big enough that it has taken them this length of time to explore it all. Now let us assume that these five people are all intelligent, quick learners but with no special skills of any kind. One day, while exploring the island they find an abandoned ship. Although seaworthy there is no crew. The islanders decide to use this ship to get home and climb aboard. Now once onboard, they decide to split up in order to run the ship so one person goes to the engine room, one to the bridge, one to the galley and so on. Slowly but surely each one learns how to use the equipment associated with their specific function on the ship. Now let's assume that this is a particularly large planet or at least a particularly slow ship so that it takes them ten years to get home. By the time they arrive, each one will have changed, evolved if you will from being an all-rounder with no special skills to being an expert in whatever ship's function they found themselves.
The same is true of biological organisms at different levels of order. Embryonic stem cells for example are pluripotent cells, blank slates if you will, capable of transforming into any cell type necessary upon receiving instruction from DNA during gestation. In the same way if we trace our evolutionary history back to the first single celled organisms, we will find that those simple creatures behaved in the same way as the people on the imaginary ship. They cooperated in order to survive, thus creating the idea of a society. Eventually after millions of years of evolution these individuals became so interdependent that they became the cells that make up our liver and kidneys and everything that makes us human. Now this doesn't directly refute Mr. Behe's argument about an intelligent designer granted, but it does in an albeit simplified manner show how simple amoebic life forms through co-operation and the raw processes of natural and sexual selection can and have shaped the diversity of life we see on this planet every day. Once again I am going to leave the final words on this subject to another and for the second time in a row to Stan Marsh. This thought is for those people who believe that intelligent design and people like Michael Behe have the answers to the origins of life. Take it away Stan:
"At first I thought you were all stupid, listening to this douche's advice, but now I understand that you're all here because you're scared. You're scared of death and he offers you some kind of understanding. You all want to believe in it so much, I know you do. We need to recognize this stuff for what it is: magic tricks. Because whatever's really going on in life and in death is much more amazing than this douche."



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