Evolving Thoughts

Evolution, culture, philosophy and chocolate! John Wilkins' continuing struggle to come to terms with impermanence... "Humanus sum, nihil humanum a me alienum puto" - Terence

Friday, December 10, 2004

One Flew over the Deist's Nest

Doing the rounds at the moment is this, seen on a few newsgroups:

Top atheist and professor Anthony Flew has finally admitted the obvious--that life is too complex to have arisen by natural causes. He now believes in the essentials of Intelligent Design theory and a "limited God", based on scientific evidence.

The greatest scientific deceit in history has been dealt a serious blow.

Rubbish. Flew's deism is antithetical to Christian and Islamic theism, for a start (Flew says as much) and all he is claiming is Spinoza's god - the distant and first causing god who has no personal agenda or relationships. And his reason is surprisingly weak - he cannot conceive how DNA got going.

Now I think there is a flaw here. It is often said (for example by Dawkins) that evolution got going when the first molecule acquired (by "chance") the property of being able to replicate itself. So for evolution to begin there had to be, it is said, a first replicator.

But this is a mistake - replicators are a sufficient cause of evolution, but they are not, in my opinion, necessary for it. And if they are not necessary for it (and in particular not necessary for natural selection) then they can themselves evolve using ordinary Darwinian processes of optimisation of fidelity of reproduction by selection.

If the original protobiological reactions generated copies of themselves, there will be differences in the stability and fidelity of copying for the different elements of that reaction cycle. Variants that are more stable will generate more copies, and variants that are more high fidelity than others will generate more copies like themselves. Selection will do the rest, and the end product will be replicators (RNA initially, followed by DNA). So there is a (feasible) argument that accounts for the evolution of replicators before there were any. Hence, the conclusion is based on an argumentum ad ignoratium.

There is no logical conundrum here. It concerns me that Flew does not see this, but then he is only following the standard opinion of hard selectionists like Dawkins. But his argument is an argument from ignorance. He may find it compelling personally, but it is not compelling logically.