Re: virus: Level Three-Belief and Utility.

Jason McVean (
Sat, 2 Nov 96 11:12:00 MST

At David M's suggestion I found this stuffed in the back of my
mail box:

David Leeper said:
> > > 2) If you imagine the mind as a landscape of peaks and valleys and mutations
> > > occuring which randomly move the replicators around the landscape, can you
> > > see how it is impossible to get stuck in a local optimum? Mutations are
> > > random, they don't seek out global or local optima, they just move their
> > > replicators around randomly.
> > If the mutations don't go far enough, they will wipe before finding any
> > nearby [improved] local maximum.
> Evolution is sneakier (is that a word?) than this. It'll mutate the
> replicators and throw a new beast at the problem. If that doesn't work
> it'll try again with another beast, and another, and another.
> Here's the secret. Not all mutation cause a change in the phenotype
> of the replicator. Mutations occur and the beast remains at the same
> spot on the fitness landscape. But _collections_ of "useless" mutations
> can combine to create a valuable mutation (See Gould on this topic).
> This combination creates a big jump that no single mutation can do by
> itself. Evolution can continue this process ad infinitum until it finally
> gets out. Evolution never gets stuck.

If you have an infinite amount of time, how do you define "getting
stuck"? That aside, isn't the diversity of life sort of evidence
for the fact that species get stuck? If every mutation found the
absolute maximum in fitness space, everything would evolve to the
same phenotype wouldn't it?


Dept. of Physics and Astronomy University of Calgary

"And it would have worked if it weren't for those meddling kids."