From: onar@hsr.no (Onar Aam)
Subject: Chess & Lionel Tun
Organization: Rogaland University Centre
Date: Wed, 11 Nov 1992 12:05:22 GMT

In article <1992Nov9.184833.16734@city.cs>, lionel@cs.city.ac.uk (Lionel Tun)
writes:
> OK, I issue a challenge. Take your favourite chess program on
> your favourite computer. Randomly change any number of bits or
> bytes in the program's executable file. If you manage to find
> a random change which makes the program better at chess, I will
> accept it as evidence that significant AND beneficial random
> mutations are possible. Oh, and I'll eat my flat cap.
> 
> There you are, this is my "SW program that simulates how
> impossible evolution actually is", your common or garden game
> of computer chess. Please report back in say ten years.
> 


A computer program is a mere algorithm. Life is a *process*. Therefore they don't
easily compare. Also: a computer operates at an extreme level of precision.
Either a bit is 0 or it is 1, there is no in between. If you consider DNA to be
similar to a computer program you need to keep in mind that it is "sloppy". It is
continuous and does not operate with exact states (except the basic nucleotides).
   Also a computer normally operates serially unlike the parallel processing DNA. 
To operate serially means that the computer performs only one task at a time. This
makes EVERY step of the computer program crucial. Therefore a change in a single
bit is also probably fatal. You see? A computer has great disadvantages to life.
It is, by far, not as flexible. But there are things we can do to make the odds
more even. If we *simulate* a computer on a computer we have almost made
ourselves a parallel computer. Instructions are still performed serially, but now
we have the power to let each instruction perform independently of each other. We
have sort of "decrucialized" the computer. If we also allow for "gradual" truth
the problem with exactness will fade away (literally). Many successful such
simulations have been made. "Tierra" is perhaps the grandslam of them all. It is
a program which simulates a "world". This world consists basically of memory
(RAM) and some "physical" laws. The originator of the program made an "organism"
which could successfully reproduce. He had let mutations be an inherent part of
the "laws" so that diversity could arise. To his surprise, after having let the
program run over night, a range of "organisms" had evolved. Some of them alot
more successful than his proto-organism. 


    
> BTW to forestall any objections, please note that a computer
> chess program is much simpler than a human brain.




This is not necessarily so. I reckon you've never heard of neural networks. If you
had, you would never have been so hostile to the abilities of the computer.
Neural networks are simplified models of the brain. A network is built up of
'nodes'. Each node performs some simple tasks, and each node also operates
independantly of each other. The nodes are allowed to communicate with each other
by exchanging information ex. the output of one node might be the input of
another. The connections between the nodes are structured in patterns or
networks, hence the name. A neural network on a computer is a quasi-program i.e. 
a program in a program. One of the basic features of a neural network is that it
is self-modifying. It does not change the overall structure of the network, but
it alters the importance of different nodes. Note that the change is not random
but based on judgements which the network does itself. This self-modifying
process is what we normally address as 'learning'. The networks have been used
for speech recognition, subway control, economical analysis, recognition of
handwriting and much more. 
     There exist chess programs which are based on neural networks. These
constantly alter themselves to improve their play. Unfortunately such programs
are yet not publically available, I think. 
     Lionel, I hope this hasn't slipped your mind as "evolutionist propaganda".
Study neural networks yourself. You will find books on the subject in any
university library. 




Onar.