Newsgroups: comp.ai.alife
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From: D J Ward <mapdjw>
Subject: Re: Life and reproduction (Or should that just be Life!)
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Date: Tue, 5 Dec 1995 10:14:16 GMT
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For my final year project entitled 'Using the Genetic Algorithm to Evolve
Group Evasive/Hunting Behaviour', I found that I felt compelled to define
the concept of life in order to produce a model.  I am fully aware of the
problems encountered in various fields as to what exactly constitues a
living organism, but why isn't a simple dictionary definition enough to
satisfy all those divided people.  (After all, we are trying to describe
a complex state of affairs here and given any general definition for life
which doesn't exceed 20,000 volumes there will of course be those exceptions
to the rule.)

Personally I found the following definition to suffice.

<Life> - State of matter characterised by the capacity for metabolism, growth,
reaction to stimuli and reproduction.

	As a mathematician I found this sufficiently abstract (after some
clarification of metabolism) to give me an idea of what sort of phase space
we are dealing with here.  This space will of course contain all those
'exceptions to the rule' but hopefully will contain the living states too!
This being the case, we at least know we are in the neighbourhood of life
and so have a chance of finding it.  I do get a little saddened by people who
persist in pursuing their pet definitions (which after all do seem to be
just some slight difference of opinion upon one or more elements of the
above definition!) in order to find this 'needle in the haystack' when in
fact they aren't even looking at the whole haystack.  They usually end up
finding just hay!

Is there no hope ?  Will everyone persist in disagreeing or can we at least
have some proper common ground!

Darren Ward

A humble postgrad studying for a MSc. in Symbolic Computation
School of Mathematics
University of Bath

'If patterns of ones and zeros were 'like' patterns of human lives and
death, if everything abount an individual could be represented in a 
computer record by a long string of ones and zeros, then what kind of
creature would be represented by a long string of lives and deaths ?'

- Thomas Pynchon.

