> From: "Kirk Elder" <gt6873d at prism.gatech.edu>
> Subject: Re: A possible definition of life.
> life needs to be free from all constraints that REQUIRE an external entity,
> that not only assigns its growth (mentally, physically, abstractly) but
> interprets its actions.
> This throws a serious wrench into the subject. I think this takes the
> photocopier out of the picture, and the thermostat.
So does any definition requiring that a living thing code for itself
AND replicate itself.
> Life does what it chooses to, when it chooses to, and how it chooses to do
> Can anybody think of a living creature, (agreed upon beforehand) that
> doesn't obey this rule.
The concept of choice, when talking about even the organisms we know,
is a a very difficult one: does a bacterium "choose" to follow a
concentration gradient of a nutrient, or is its behaviour programmed
to such an extent that it is involuntary? Does a virus "choose"
which cells it attaches to, or whether it will infect it? I suspect
the smaller you go, the more programmed things are, in terms of
intermolecular interactions; thus the concept of "choice" in
determining what an organism does, falls away.
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
"Every year is getting shorter, never seem to find the time..."