To make things more confusing, some RNA viruses can "metabolise" outside
of cells, given the proper conditions. The phenomenon of natural
endogenous reverse transcription (NERT)--in which cell-free RNA viruses
synthesize DNA--has been described in several viruses, including HIV-1,
where it may play a role in heterosexual transmission because of the
abundance of nucleoside triphosphates in uterine environment.
The Journal of NIH Research
In article <m0wHUt6-0004OBC at uctmail2.uct.ac.za>,
Ed Rybicki <ed at molbiol.uct.ac.za> wrote:
>> From: mattst at cogs.susx.ac.uk (Matthew Stanfield)
>> Subject: A possible definition of life.
>>> I have, what I consider, a possible definition of life.
>>>> I have been reading about Artificial Life (studying for college) and have hit
>... Please could someone explain to me why the age-old problem of
>> defining life is not solved by:
>>>> "Life (on Earth) consists of all things built by DNA."
>>Because, Matthew, there are those of us who think viruses - at least
>when in their hosts - display the attributes of living things. And
>many viruses have RNA genomes. This is not to mention the
>possibility that computer viruses are, given a brand new niche of
>electronic labyrinths in which to electronicaly multiply, also alive
>(who are we to argue with Stephen Hawking?). Or memes (thought
>viruses - like the tune of "The Macarena").
>>No, Matthew: I prefer:
>> "Life (anywhere) is the phenomenon associated with th replciaiton of
>self-coding informational systems".