Natural Selection of Algorithms

OK, this is impractical right off the bat because algorithms don’t reproduce and they don’t get some randomness thrown in like biological stuff does. Still, after reading Where lies the physics of mind?, I think there’s a very good point to be made here. Evolution does not make sense. Yes, natural selection is fine, it’s nearly obvious. Evolution is obvious at first glance, but look closer and you’ll see it’s impractical and not the way things actually are.

…one still might imagine some kind of natural selection process being effective for producing approximately valid algorithms. Personally, I find this very difficult to believe, however. Any selection process of this kind could act only on the output of the algorithms, and not directly on the ideas underlying the actions of the algorithms. This is not simply extremely inefficient; I believe it would be totally unworkable.

That’s right. Natural selection as a way to create valid algorithms is totally unworkable.

In the first place, it is not easy to ascertain what an algorithm actually is, simply by examining its output. (It would be an easy matter to construct two quite different simple Turing machine actions for which the output tapes did not differ until, say, the 2^65536th place– and this difference could never be spotted in the entire history of the universe!) Moreover, the slightest ‘mutation’ of an algorithm (say a slight change in a Turing machine specification, or in its input tape) would tend to render it totally useless, and it is hard to see how actual improvements in algorithms could never arise in this random way. (Even deliberate improvements are difficult without ‘meanings’ being available. This is particularly borne out by the not-infrequent circumstances when an inadequately documented and complicated computer program needs to be altered or corrected; and the original programmer has departed or perhaps died. Rather than try to disentangle all the various meanings and intentions that the program implicitly depended upon, it is probably easier to just to scrap it and start all over again!)