“A lie can travel halfway round the world before the truth has got its boots on” (Mark Twain, attributed).

In my previous post I gave some background on intelligent design, the theme of a talk I recently attended by Dr Alistair Noble. This time, I’ll try and address his claims.

It is easy to say something that is not true. It is not always so easy to explain why it is not true. Such is my problem here. I can summarise Dr Noble’s arguments into a few sentences, but it takes paragraphs to explain why they are wrong. Here goes!

His argument centered around DNA. Dr Noble’s background in chemistry, specifically in trying to artificially synthesise chemicals, showed him how difficult it was to make even simple molecules. He explained his problems with DNA and used two specific examples to illustrate his argument: the bacterial flagellum and cytochrome C. His arguments were essentially:

they look designed they are too complex to have arisen by chance

The design argument can be easily refuted. Apparent design does not mean actual design. Humans are extremely good at seeing things where they do not exist, like shapes in clouds and Jesus on burnt toast. This is a well-known psychological phenomena called paradolia and can lead us to see design where none exists.

The second claim requires a bit more care. DNA, the bacterial flagellum and Cytochrome C are all highly complex and could not have evolved by chance. In fact, as Dr Noble so carefully illustrated, Cytochrome C would have taken longer than the lifetime of the universe to arise by chance. So if they did not arise by chance then they must have arisen by design, surely? Well, no.

This conclusion can only be made if you have a deep misunderstanding of evolution. At a very basic level random mutations occur which may be beneficial, neutral, or detrimental to an individual. Then natural selection ‘selects’ those mutations which are beneficial and ‘rejects’ those that the detrimental. Small changes over long timescales lead to big changes, mutations can build on each other and can be co-opted to other functions. The bacterial flagellum is a perfect example, with studies showing how molecules were co-opted from other functions to form the flagella. At no point was there a useless proto-flagellum.

ID proponents, including Dr Noble, focus on the random aspect of evolution but completely ignore the selection part, which is arguably the more important aspect. If there were no natural selection then their claims would be valid, but its presence provides a beautifully simple explanation of how complex molecules, complex biological components, and even complex organisms could arise.

Next time, my review of the talk.

Author

Sarah Hearne: hearnes[at]tcd.ie

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