The notion of "life-capable" or "life-incapable" seems more useful
than a flat declaration of "live" vs. "dead". The fact is that "life" is
a "hard science" question but really is a philosophical construct.
A living thing requires more than molecular structure. It needs the
cellular structure to mechanize the life processes. That is, without
the organized presence of the cellular structures (which in eukaryotes
are rather complex indeed) that can interpret the molecular
information and make use of the metabolic energy, the purely
biochemical macromolecules are not truly "living".
The current state of metabolism is not really pertinent. What is
important is the potential to metabolize and to reproduce using
the internally generated information and metabolic energy.
Dormant life stages have that potential. Dead ones do not.
"George Hammond" <ghammond at mediaone.net> wrote in message
news:3A302B80.FBDB4526 at mediaone.net...
> John Hunter wrote:
> > Gee, I didn't know you were going to get philosophical on me. But
> > since you did.... I think it presents an interesting case, one that
> > I'll think about for a while and get some advice from my philosophy of
> > science friends. But my off-the-cuff opinion is that these organisms
> > are 'not alive' (I don't use 'dead'). I think they are life capable,
> > but I don't see any reason to call them alive if they have no
> > metabolic processes, and in the absence of external imposition
> > (somebody finally gets around to watering the plant), they will remain
> > 'not alive'. Thus they lack the ability to act as agents on their own
> > behalf, manipulating the environment in one way or another. I think
> > that is a necessary condition for a living thing. So perhaps we
> > have three categories: dead, life capable, and alive.
> > Then a person on the operating table who has just lost a heart beat
> > (or whatever the appropriate standard for clinically dead is) is life
> > capable, but a person 30 years in the grave is not. A cryogenically
> > preserved animal is life capable.
> > What do you think?
>> GH: Thanks for the Philosophy input.. but I think the answer lies
> in physical investigation of the molecular structures involved.
> For instance, is there still water trapped inside the cytoskeletal
> microtubule structure inside the cells? Are there still
> configurational dimer transition oscillations in the microtubule
> structure? These are the hard questions that need answers..
> one can jawbone all afternoon about Philosophy of course, but
> it isn't really worth much.
> When I say "dead or alive", I'm hardly asking a "Philosophy"
> question, I'm asking a hard science structural question viz the
> points just mentioned.
> > John Hunter
> > >>>>> "George" == George Hammond <ghammond at mediaone.net> writes:
> > George> GH: Yeah... I've discovered that much, Glucose and
> > George> Trehalose (sugar molecules) bind to the polar sites
> > George> normally occupied by water and thereby lock the structural
> > George> mechanism into a rigid mechanical state until water is
> > George> added again. Trehalose I would guess is your "chaparone"
> > George> molecule mentioned above. The interesting question to me
> > George> is whether or not these animals are technically "dead" or
> > George> "alive" while they are in this state? Claims that "no
> > George> metabolic activity" takes place while they are in the
> > George> Cryptobiotic state seem to be confirmed. If this is so,
> > George> then it seems to tell me that "Life" ultimately exists at
> > George> the "molecular" level and not at the cellular level.
> > George> Would you agree that this phenomena supports that
> > George> conclusion?
> BE SURE TO VISIT MY WEBSITE, BELOW:
> George Hammond, M.S. Physics
> Email: ghammond at mediaone.net> Website: http://people.ne.mediaone.net/ghammond/index.html> -----------------------------------------------------------