A possible definition of life.

David Hagerberg mik_daha at luecology.ecol.lu.sexx
Thu Apr 24 17:20:18 EST 1997

Ed Rybicki wrote:
> > 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
> > it.
> > 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?

Yes, the term of "choice" was unfortune. We can look upon it in this way 
instead. The bacterium follow a concentration gradient by action and not 
by chance. That is, if it has the possibility to feel the gradient. I 
think Kirk has to evolve this thought a bit!

  Does a virus "choose"
> which cells it attaches to, or whether it will infect it?

Is virus alive?

  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.

I think rather the tighter coupled to the genes are the responses. In 
brained animals the actions might be more and more coupled to some 
neurotic program, inherited as culture. No, choice is not good.

> "Every year is getting shorter, never seem to find the time..."

"What's another year?"

John Savard: 
"Thus, as long as we allow the Bible to round things off to the nearest 
cubit, there is no problem."

Interpreted by his disciple, David Hagerberg, to:
"Thus, as long as we allow the Bible not to be taken literally, there is 
no problem taking it literally!"

More information about the Mol-evol mailing list

Send comments to us at biosci-help [At] net.bio.net