Re: Evolution's problems




On 12/30/05 4:25 PM, in article
1135977932.165306.203540@xxxxxxxxxxxxxxxxxxxxxxxxxxxx, "Radix2"
<dyera@xxxxxxxxxx> wrote:

>
> Robert J. Kolker wrote:
>> Raymond Griffith wrote:
>>>
>>>
>>> Actually, at least one virus (IIRC, polio) has been assembled from
>>> non-living pieces already.
>>
>> Then the matter is settled. Natural processes are sufficient to produce
>> a replicating chemical complex. The replication shows that it is alive.
>>
> <snip>
>>
>> Bob Kolker
>
> Honest question.. I was always under the (mis?)-apprehension that a
> virus was generally not considered to be "alive" in that it cannot
> replicate itself without the aid of host cells as opposed to bacterium,
> which can given the right environment (ager for instance). Is this a
> pedantic or erroneous view?
>

Well, this is a pretty hotly debated topic. It depends, in part, on how you
define "life".

The problem with your exclusion is that "host cells" could be considered to
be "the right environment" for viral replication. Humans cannot reproduce
without the assistance. Consider that there is a need for a male and a
female, a sperm and an egg. The egg eventually acts as host for the sperm,
and the process of cellular replication has to occur within a certain
environment to produce viable offspring.

But I recommend for your perusal
http://www.ibiblio.org/astrobiology/index.php?page=origin06

<Quote>

Are viruses qualified as living?

This is a very interesting question which has instigated many heated debates
in scientific circles. Why are viruses such a big deal? Well, viruses are
interesting because they are neither inanimate nor living; a virus is
"midway between brute matter and living organism" (Wolfhard Weidel). Because
of this ambiguity, it is difficult to define and classify viruses. Although
viruses are not composed of cells, they possess all the other
characteristics of living things. They replicate, require energy (from
living cells), adapt, respond to stimuli and display heredity. Because
viruses satisfy six of the seven characteristics of living things, they are
on the verge of being classified as a living organism. Perhaps the haziness
surrounding our very definition of "living" is at fault for not including
viruses as a form of life. As scientist Wolfhard Weidel once said, "nothing
brings us so close to the riddle of Life - and to its solution - as
viruses".

</Quote>

Another interesting web essay is found at
http://www.sciencemag.org/cgi/content/full/295/5563/2215

<Quote>

What is the definition of life? I remember a conference of the scientific
elite that sought to answer that question. Is an enzyme alive? Is a virus
alive? Is a cell alive? After many hours of launching promising balloons
that defined life in a sentence, followed by equally conclusive punctures of
these balloons, a solution seemed at hand: "The ability to reproduce--that
is the essential characteristic of life," said one statesman of science.
Everyone nodded in agreement that the essential of a life was the ability to
reproduce, until one small voice was heard. "Then one rabbit is dead. Two
rabbits--a male and female--are alive but either one alone is dead." At that
point, we all became convinced that although everyone knows what life is
there is no simple definition of life.

</Quote>

Indeed, both of these articles define "life" somewhat differently. Yet both
seem quite reasonable, and there is some overlap in the definitions.

In my opinion, if a virus is not actually "alive", it is almost there, an
"almost life" as it were. A Creatorial Mistake, perhaps? (with no intent to
be sacrilegious!). We try to "kill" viruses such as AIDS. How can we "kill"
something that isn't alive?

So your question is far from pedantic. But there are no easy answers.
Perhaps the problem is that we haven't actually defined "life" very well,
and have defined "life" based on pre-microbiological notions.

Regards,

Raymond E. Griffith

.

Relevant Pages

  • Re: Did life originate with viruses?
    ... inconceivable to me that life could have originated as a parasitic ... with fine print forcing us to conclude that the virus was a ... Discover story mentioned all too briefly was that viruses were the ... that they have linear DNA like eukaryotes rather than circular DNA. ...
    (sci.bio.evolution)
  • Re: No life created from scratch
    ... Darwin123 stated that DNA was created from scratch and provided the ... viruses from scratch. ... together to obtain a DNA copy of the polio virus genome. ... The idea that life - or a virus was created from scratch is a complete ...
    (talk.origins)
  • Re: Did life originate with viruses?
    ... that life could have originated as a parasitic virus. ... conclude that the virus was a 'parasite' of some membrane bound host that ... Activated nucleotides, like modern viruses? ...
    (sci.bio.evolution)
  • Re: Did life originate with viruses?
    ... This "monstrous discovery" is that of the Mimivirus, ... and is one of the few viruses that can be seen with an ordinary microscope. ... for the life of me, I can't see what relevance it could possibly have to ...
    (sci.bio.evolution)
  • Re: The Reasonable Minority
    ... But saying evolution is based on ... not cover abiogenesis - that is how life got started. ... to living when they become part of you. ... That's easy to determine and no a virus won't qualify. ...
    (talk.origins)