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From: bhorton@aries.dpi.tas.gov.au
Subject: Re: Q: Name of this GA-operation ?
Organization: Department of Primary Industry and Fisheries
Date: Wed, 8 Mar 1995 06:24:23 GMT
Message-ID: <bhorton.6.00116895@aries.dpi.tas.gov.au>
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Keywords: mutation translocation
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In article <3j2d3e$t8v@news.imssys.com> jimk01@imssys.imssys.com (Jim Kennedy) writes:
>From: jimk01@imssys.imssys.com (Jim Kennedy)
>Subject: Re: Q: Name of this GA-operation ?
>Date: 1 Mar 1995 18:06:38 GMT

>When I wrote a "GA-inspired program" to work with permutations (as your
>problem seems to be), I found that I needed to invent operators: I
>"invented" the one you mention, and I called it "mutation."  With
>permutations you can't just flip bits, so it seems reasonable to flip
>positions on the chromosome. -- What did you use for crossover?

>Jim 

>:[snip]
>: For example :
>:   123456789
>:     ^^  ^^
>: will be transformed to  :
>:   127856349
>:     ^^  ^^

(Real) geneticists used to use the term 'mutation' for any change in the 
chromsome structure, and they still do if they don't know the cause of the 
change.  But in GA we always know the cause, and the term 'mutation' is 
normally restricted to a 'point mutation' involving a single bit.

It would avoid confusion if we maintain this convention and continue to use 
the geneticists term 'translocation' (as it is already used in GA) to indicate 
the relocation of one section of the chromosome to another section. 

The example actually involves two simultaneous translocations by 
swapping rather than a single deletion and reinsertion (that would also be 
considered a translocation).  However, I doubt whether we need a special term 
to distinguish double translocations from single translocations.

Brian Horton

