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From: efrethei@afit-ab.arpa (Erik J. Fretheim)
Newsgroups: comp.ai.neural-nets
Subject: Re: NN Question
Keywords: natural selection
Message-ID: <971@afit-ab.arpa>
Date: 9 Mar 89 12:49:01 GMT
References: <32125@gt-cmmsr.GATECH.EDU> <10624@pasteur.Berkeley.EDU> <6082@sdcsvax.UCSD.Edu>
Reply-To: efrethei@blackbird.afit.af.mil (Erik J. Fretheim)
Distribution: usa
Organization: Air Force Institute of Technology; WPAFB, OH
Lines: 23

In article <6082@sdcsvax.UCSD.Edu> bloch@sequoya.UUCP (Steve Bloch) writes:
>In article <10624@pasteur.Berkeley.EDU> brp@sim.UUCP (bruce raoul parnas) writes:
>>In article <32125@gt-cmmsr.GATECH.EDU> kirlik@hms3.gatech.edu (Alex Kirlik) writes:
>>>One answer would seem to be that there is a tremendous amount
>>>of additional processing in the brain that is extraneous to
>>>the processing critical to the task being modeled, yet we are
>>>only modeling this "critical" segment. 
>>
>>Natural selection would eliminate a great deal of "extraneous" processing
>
>Not necessarily.  Natural selection is a good improviser, but a terrible
>designer, and in particular it's very reluctant to throw away something
>just because it no longer serves its original purpose.  In addition, some
>of the hypothesized "extraneous processing" might be what a designer would
>call "redundancy for fault-tolerance", which is selected FOR within
>reasonable limits.


Agreed that natural selection would not trim extraneous processing, in fact
as you mention it would tend to enhance it as redundant systems. 
Take for example pilots, natural selection tends to enhance the numbers 
who fly airplanes with redundant systems - especially when external stresses
are induced.