A possible definition of life.

Ed Rybicki ed at MOLBIOL.UCT.AC.ZA
Mon Apr 21 03:08:26 EST 1997


> From:          foster at skink.cs.uidaho.edu (James Foster)
> Subject:       Re: A possible definition of life.

> In article <m0wHUt6-0004OBC at uctmail2.uct.ac.za> ed at MOLBIOL.UCT.AC.ZA ("Ed Rybicki") writes:
> 
>    No, Matthew: I prefer:
> 
>     "Life (anywhere) is the phenomenon associated with th replication of 
>    self-coding informational systems".
> 
> This is too imprecise.  To which phenomena do you refer?  Replication?
> Self-coding?  Decoding?  Translation?  Does your definition make my
> copy program alive?  How about my photocopier? 

The phenomenon is life: it is associated with the very act of 
replication of entities that encode themselves - like us, or viruses 
(analogue or digital).  Your photocopier is not alive as it does 
nothing except transcribe - it certainly doesn't make more 
photocopiers.  Your copy programme probably can't copy itself (you 
would almost certainly get an error to do with it being active while 
was trying to copy itself).  It can copy another copy of itself, but 
that isn't the same, is it?

> I remember a philosophy paper in college arguing that thermostats were
> alive: they are self regulating, have internal representations, must
> be in a host, etc. 

But they very definitely do not make more of themselves, which pretty 
much cuts them out of the game, by my definition.

> Personally, I think defining life is a fool's errand.  We're not
> really interested in "what is life".  Ed is interested in how viruses
> do what they do.  Alife people are interested in algorithms which
> display interesting behaviors.  You don't have to define the term to
> justify what you do, or even as a prerequisite to doing it.

Of course you don't: but as intelligent apes, we are driven 
inexorably to try to find reasons for things, and definitions to 
order things.  Personally I don't give a damn, but it is an 
interesting philosophical exercise (Damn!  There went the P word, 
after I've been rubbishing it these many years.  Ah, well, and I used 
not to be a taxonomist, either...).

"Life: is just a bowl of All-Bran
You wake up every morning and it's there..."

Marriot/Lane, "Ogden's Nut-Gone Flake", 1968.

                     Ed Rybicki, PhD  
      Dept Microbiology     |   ed at molbiol.uct.ac.za   
   University of Cape Town  | rybicki at uctvms.uct.ac.za
   Private Bag, Rondebosch  |  phone: x27-21-650-3265
      7700, South Africa    |   fax: x27-21-689 7573
    WWW URL: http://www.uct.ac.za/microbiology/ed.html      
                                        
    "Out here on the perimeter, there are no stars..."



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