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From: altenbur@plains.NoDak.edu (Karl Altenburg)
Subject: Re: "What is Life?"
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Date: Mon, 30 Jan 1995 17:10:05 GMT
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Brian Holtz (holtz@netcord.Eng.Sun.COM) wrote:
: A tornado is alive?  I think not.

: Life is the ability to reproduce and evolve.  

Than all individuals are dead?  I'll grant that most organisms have
a capacity to reproduce, but none of them evolve (unless we're
talking Lamarck again).

: A more involved
: definition is required if we want to be able to tell living things
: from inanimate, unborn, and dead things.  An entity can be
: considered alive if and only if it 1) is of a kind that usually can
: reproduce and evolve, and 2) has achieved independence of a parent's
: direct, continuous, and non-fungible assistance to its environmental
: interactions, and 3) is able to reproduce or interact with its
: environment.

: Thus:


: - Lt. Cmdr. Data isn't alive.
But didn't he repoduce?  And I'm sure he'll pass on traits to his offspring
that made him more fit, and so will his offspring to their offspring.

: - Tornados and fires aren't alive.
Why isn't a fire alive?  It reproduces, evolves into different types of
fires as resources are found or used up, and it does depend on its
parent to help it once it has spread.

: - Ideas aren't alive.
Very hard to disprove.  Many of the ideas (memes) that are distributed around
the world have been reproduced, have evolved, are existing in the absence
of their original parent.

: - Viruses are alive.
If ideas aren't alive why is a virus alive?

: - Tierrans are alive.
This really seems to be a bias.

Although reproduction is an important characteristic of life as we know
it, there are other equally important characteristics:

precise organization
metabolism
homeostatis
movement
responsiveness
growth
adaptation to environmental change

I guess I would place a strong emphesis on the organization of a system.

--
Karl R Altenburg				altenbur@plains.NoDak.edu
North Dakota State University, Fargo, ND  58105

All things are artificial, for nature is the art of God.  SIR THOMAS BROWNE
