Are viruses alive?

[Steven_H Harwood]

On 2 May 1995, Walter Hoeksma wrote:

> Doesn't the argument over whether or not viruses are alive
> really depend upon on how one chooses to define life. Since I know
> of no standard universally accepted definition of life, the
> argument becomes academic. If one views life as being cell based
> clearly viruses are not alive. If one views life as being any nucleic
> acid system controlling its own replication, viruses can be viewed as
> living. Would certain plasmids also be alive by this later criterion?
> So if you wish to view viruses or nucleic acid systems as alive broaden
> your definition of life to include them. If not restrict your view of
> life to celular systems to exclude viruses. If anyone can provide a
> universally accepted view of "life" I'll be able to answer the question
> for myself.
> 
>  Walt Hoeksema
>  YD03 at MUSIC.FERRIS.EDU
> 
I'm afraid I can't take this discussion about whether viruses are alive 
or not all that seriously.  It doesn't matter what we think they are 
since our classifications are constructs of our minds and do not 
influence what viruses are or what they do.  What they do is to 
parasitize cells from organisms ranging from bacteria to humans and in so 
doing (often) cause disease in those organisms.  They do replicate their 
DNA and evolve and coevolve with their hosts. Thus, the information 
contained in their DNA evolves and persists in time.  

Are viruses living?  Perhaps the newsgroup might find the following 
humorous.  I found it in Efraim Racker's book
entitled "A New Look at Mechanisms of Bioenergetics"  Academic Press, 1976.

"On the origins of life:  You are all aware that the energy required for
life is ultimately derived from the light of the sun with the aid of
photosynthesis which takes place in chlorophyll-containing membranes.  A
molecular biological version of the origin of life runs something like
this:  On the first day God said, "let there be light", and there was
light.  ON the second day God said, "Let there be water", and there was
water.  ON the third day God said, "let there be membranes which contain
chlorophyll and which can utilize the energy of light."  On the fourth
day the chlorophyll-containing vesicles made a ~ and the squiggle
generated ATP, GTP, UTP, and CTP.  On the fifth day God polymerized ATP,
GTP, UTP, and CTP, and created ribonucleic acid and God saw that it was
good.  On the sixth day the Lord said it was not good for RNA to be alone
and he caused a deep sleep to fall upon RNA (he incubated at 0 degrees)
and he took a rib out of (rib)onucleic acid and made DNA from it (the rib
was later renamed oxygen).  And RNA and DNA were both naked but they were
not ashamed.  On the seventh day God rested and that's when all the
trouble started.  There was the ~ with its bad influence and persuaded
DNA to do what it was not supposed to do.  DNA and RNA made hybrids and
afterwards they felt ashamed because they were naked.  So they covered
themselves by making a coat protein and this is how the first virus was
created.

God was very angry when he saw it and blamed RNA, and RNA blamed DNA
and DNA blamed the ~ (this was the first case of passing the buck).  But
God did not like to have viruses float around in Eden and he banned RNA
and DNA onto Earth where they lived unhappily ever after.>

And as to what constitutes life, I like to ponder the following:

"Life is matter which has become sufficiently organized to describe itself."

Have a nice day.

Steve Harwood
Dept Agric. Chem.
Oregon State University
Corvallis, OR  97331
>