Are viruses alive?

[Peter S. Shenkin]

In article <3605 at fcs280s.ncifcrf.gov> toms at ncifcrf.gov (Tom Schneider) writes:
>
>In article <CMM.0.90.2.711650592.pkarp at Rockaway.AI.SRI.COM> pkarp at ai.sri.com
>(Peter Karp) writes:
>
>|Harold Morowitz' forthcoming book, "Metabolism Recapitulates
>|Biogenesis: The Beginnings of Cellular Life" has a succinct definition
>|of living systems.  To paraphrase from a draft of the book, an
>|autonomous biological self-replicating system is a molecular
>|self-replicating entity that is capable of evolving, and that operates
>|in the absence of other self-replicating entities.  Therefore, a virus
>|is not an autonomous biological self-replicating system because it
>|requires the presence of other self-replicating entities to replicate.
>|Whether it is alive or not depends on whether you equate life with an
>|autonomous biological self-replicating system, or simply a biological
>|self-replicating system.
>
>Hmm.  So humans must not be "autonomous biological self-replicating systems"
>because we depend on oxygen, vitamin C and various amino acids.  

Morawitz specifies that live things cannot depend on other *self-replicating*
entitities.  "Oxygen, vitamin C and various amino acids" are not 
self-replicating, so they don't count.  The real reason we're not alive
is that we eat plants and animals.

>   .... But I think
>that most people would claim to be alive (or object violently if someone else
>claimed that they were not!)....

Now, now.... just because we claim to be alive, or object violently if
someone else claims we're not, doesn't mean we really ARE alive....  :-)

  -P.
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Peter S. Shenkin, Department of Chemistry, Barnard College, New York, NY 10027
(212)854-1418    shenkin at avogadro.barnard.columbia.edu   shenkin at cunixf.BITNET
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