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From: stevens@prodigal.psych.rochester.edu (Greg Stevens)
Subject: Re: "What is Life?"
Message-ID: <1995Feb8.052542.28160@galileo.cc.rochester.edu>
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References: <jhansen-120195102007@cetq10.coe.uga.edu> <1995Feb2.161422.3233@galileo.cc.rochester.edu> <3h5snd$9p2@engnews2.Eng.Sun.COM> <1995Feb7.151910.21325@galileo.cc.rochester.edu> <3h8vta$sf3@engnews2.Eng.Sun.COM>
Date: Wed, 8 Feb 95 05:25:42 GMT
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In <3h8vta$sf3@engnews2.Eng.Sun.COM> holtz@netcord.Eng.Sun.COM (Brian Holtz) writes:
>In article <1995Feb7.151910.21325@galileo.cc.rochester.edu>,
>Greg Stevens <stevens@prodigal.psych.rochester.edu> wrote:

>>When you mourn the death of your pet dog, you do not mourn the loss of its
>>ability to reproduce or the loss of it ability to participate in the
>>evolution of dogs.  You mourn its ongoing behavior [...]

>As I've said perhaps a dozen times in recent postings, I distinguish
>between life-as-a-phenomenon and aliveness-as-an-individual-attribute.
>When Spock says "Captain, there is life on this planet", does he
>really only mean that there are a non-zero number of entities that are
>as vivacious as a dog?

Um, actually, that's what I always assumed; being somewhat of a Star Trek 
laymen, though, I may be wrong. 
 
>Imagine a planet on which there somehow suddenly arose a single
>superdog, doglike in every sense except irreproducible and immortal,
>and specifically doglike in that it cannot change over its eternal
>lifespan any more than a dog changes over its mortal lifespan.  When
>the Enterprise approaches this planet, should Spock report life on it,
>or not?  

Yeah, a weird life-form that is unlike any they have encountered before.
Like so many others that they encounter....

>If he should, then when Spock sees the Red Spot on Jupiter,
>should he report life on Jupiter?  What is the difference between
>the superdog and the Jovian Red Spot?

The red spot is self-organizing but not self-producing.  That is, it is not
specified by a network of production componants that are continually
producing and maintaining it.  The individual dust and gas bits do not
produce other gas bits, and further there are no boundry-componants --
no gas bits that specify a concrete topology in space.

>>>But what sort of structural criterion could include viruses and
>>>exclude fires?  

>>Well, autopoiesis theory has a shot at it.  A system of self-producing 
>>componants which maintain a relation-static organization within physical
>>boundries.

>How can a fire or tornado or Jovian Red Spot not qualify?  

They are not closed production systems (a series of production componants
where the function of each componant within it is specified in terms of
production of other elements of the system, and there are specific boundry-
elements constraining it in space).

>For that
>matter, how can a Tierran qualify?

It does not.  But I have no problems with this, as I do not think they are
alive.

But all cells do.  All of the chemical componants of a cell (lipids,
nucleic acids, etc) can be defined relationally in terms of the production
of other elements of the cell and the maintanence of their relations,
plus there are specific componants that are boundry componants.

>>[Life] seems to be about dynamics behavior of ORGANISMS, not populations.
>>See my earlier comment about the pet dog.

>See my comment about superdog.  Complex, adaptive, self-maintaining
>behavior alone does not qualify a phenomenon as life.

You are assuming that super-dog is not alive.  I still don't see why not,
except that it does not fit your definition, which is circular.  Do you
have any other, independent intuition that people would not consider it
alive?  It eats, it sleeps, it barks, it shits....

>>If you are not requiring that what produces it is of the same species
>>or type of organism, then cars are VERY alive because they are
>>produced en mass!

>Cars do not reproduce.  Cars do not evolve.

They are produced, and they are produced-AGAIN (RE-produced).  With each
production sequence there ongoing change which is subject to a kind of
selection for which types of cars get produced-AGAIN (RE-produced).
By your statement that living things do not have to be reproduced by the
same type of thing, the fact that humans both produce and reproduce cars
seems to not be an exclusionary criterion.

>Not all of what biologists study is biological life, but all
>biological life happens to be studied by biologists.  Again: why do so
>few biologists study fire?

Fire is not a bounded system of production componants.  I would not call
it alive at all.  But it could be said to evolve, in the same way cars could
be said to evolve.  Neither of these are life, and neither is (IMHO)
Tierra.  Your definition classifies all of these as life, it seems to me.

> But if you
>defined fires or Jovian Red Spots to be alive, I'd want to know your
>explanation of why biologists don't study them.

I never did.  The idea that life is simply self-organization is an obvious
straw man.  Read back through this post and previous posts of mine.

Greg Stevens

stevens@prodigal.psych.rochester.edu

