Is a Virus alive?

[Valjean]

I'll have to go with what I learnt at 16 years old in Biology

ALL living things follow MRS GREN
Movement (has some form of movement - trees blowing in the wind count)
Respiration (any gas exchange system)
S
Growth (body of the organism grows - bacterial cells do this also)
Reproduction (whether asexual or sexual, the organism must make more of the organism)
Excretion (waste products are excreted
Nutrition (Opposite of excretion - absorbs nutrients from food or surroundings)

Forgot what the "S" stood for.

And I don't think viruses follow all of those including - respiration, growth, excretion, nutrition

(S = sensitivity.)
Viruses don't exhibit a single one of these qualities.

 

[methylatedghosts]

Aha course it is.

But I think viruses do exhibit
R for reproduction. Virus --> cell ---> more virus

So as far as that goes, I think they have reproduction pretty well covered

 

[Valjean]

Balderdash!, my ghastly friend. Viruses can't reproduce any more than:

A: "Palpable poppycock"
B: Print A
C: Goto B

...can reproduce.

Viruses are DNA or RNA programs to replicate their self-replication programs.
They have no means to do this themselves. They "reproduce" only when their programs find their way into a cell's programming machinery, where their programs instruct the cells to endlessly copy their "copy endlessly" programs -- plus assemble some protein sheaths.

This can be reproduced exactly with a little bit of programming language. A program to copy itself endlessly can easily be written and, when introducd into a computer, will do exactly what a virus does.

If you believe a virus reproduces you must also concede that a computer program reproduces in exactly the same way.

 

[methylatedghosts]

But is that not still reproducing?

A robot that builds robots that build robots that build robots that build robots "reproduce" in the same way, provided they are "handed" the construction material - which is what a cell does for a virus no?

But anything that doesn't cover all of MRS GREN isn't alive. A ceiling fan Moves but it is not alive, and so, a virus doesn't cover all of MRS GREN, so it isn't alive - it just reproduces in a robotic sense

 

[Halcyon]

Balderdash!, my ghastly friend. Viruses can't reproduce any more than:

A: "Palpable poppycock"
B: Print A
C: Goto B

...can reproduce.

Viruses are DNA or RNA programs to replicate their self-replication programs.
They have no means to do this themselves. They "reproduce" only when their programs find their way into a cell's programming machinery, where their programs instruct the cells to endlessly copy their "copy endlessly" programs -- plus assemble some protein sheaths.

This can be reproduced exactly with a little bit of programming language. A program to copy itself endlessly can easily be written and, when introducd into a computer, will do exactly what a virus does.

If you believe a virus reproduces you must also concede that a computer program reproduces in exactly the same way.

I would say that a virus reproduces. It's method of reproduction is the hijacking of another organism's machinary, but the end result is that the virus causes it's own reproduction.

 

[Super Universe]

Something is alive if it can be killed.

 

[Valjean]

I think your reasoning is circular, SU. One definition depends on another.

If I smash a pot, have I killed it?

 

[Super Universe]

I think your reasoning is circular, SU. One definition depends on another.

If I smash a pot, have I killed it?

Exactly...

 

[Comet]

I love circular reasoning! Its like ablogic!

To those of you who have said that a virus is not alive:

Is it more alive than a pot? and I'll ask again: Do you think that it has the properties to "become" alive someday? (assuming you are the scientific/evolutionaries)

 

[Halcyon]

I love circular reasoning! Its like ablogic!

To those of you who have said that a virus is not alive:

Is it more alive than a pot? and I'll ask again: Do you think that it has the properties to "become" alive someday? (assuming you are the scientific/evolutionaries)

More alive than a pot? Lol, good question. I'd say either something is alive or it is not, so i would say no, its not more alive than a pot.
A pot is the end result of a chemical reaction, much like a virus.

A pot has cannot reporduce itself, yet when a pot is given to a potter it can be reproduced - much like a virus is reproduced by a cell.

I said way back that some viruses have incorporated cell membrane lipids into their structure, so in theory i can see the possibility of a virus becoming a true life form, as opposed to a collection of organic structures, at some point in the distant future.

 

[methylatedghosts]

I think if we look at MRS GREN, it is by that definition "more alive" than a pot (but that's like being a little bit pregnant), but because it doesn't cover all of them it is not alive.

The way to see a virus, is like a normal extra-cellular messenger like we produce in our own bodies. One cell, due to some sort of stimulus, releases a chemical. Another cell elsewhere absorbs that chemical and causes a chemical chain reaction inside that cell which causes it to release either the same chemical or a different one, or causes the cell to duplicate and multiply. Sometimes cells can release these chemicals encased in cell membrane lipids. For a virus, it is exactly the same thing.

Virus -------> Cell -------> RNA/DNA replication -------> lipid structure forming -------->virus released

Chemical signal ---->Cell----->Chemical reaction------>chemical forming------>chemical released

There it is in relatively simple terms

 

[Comet]

If Mrs Green killed the virus in the study with the candlestick, then Miss Scarlett ran off with Professor Plum to the Kitchen for some extra cirricular activities! :yes:

Thus, Mr White and Colonel Mustard say, the virus must have been alive to be killed.

(Meanwhile: Mr Green and Mrs White kept playing CLUE, completely clueless)

 

[methylatedghosts]

You know, Comet, I think you might be on to something there...

 

[painted wolf]

I find viral evolution fascinating. The line between the most complex DNA virus and the simplest single celled organism is actually quite thin.

I often wonder if viruses aren't secondarily simplified. Could it be that they gave up the complex machinery of replication to become better parasites? After all, many obligate parasites loose systems that their non-parasitic cousins have. (such as respiratory organs, much, or all of the digestive system, and so on.)

A virus isn't just inserting its genetic code into a cell... some lay dormant until they reach a 'critical mass' or until the environmental conditions are just right. They evolve at tremendous rates, a criteria of life. (not the speed, but the influence of natural selection.)

What did the virus use to replicate before the cell?
Aggressive competition between the protocells in the early world would have favored a 'stripped-down' lifeform that could get its genes into their rivals to usurp their more complicated genetic machinery. Thus the evolution of the cell and the virus could have happened in tandem.

Anyway, my point is that the line between life and non-life may not be as clear-cut as many think it is. Further research into protocells and other probiotic organisms may make the definition even more tricky.
Like the way the study of genetics has complicated the definition of 'species'.

wa:do

 

[rojse]

I got into this debate again the other day and it fascinates me..... as does the lowly virus. So, I'll ask here:

Is a virus alive?

I've agrued both sides, and I don't really know how I feel about it. Thought I'd get some more opinions since I find it interesting.

I still don't know what to think of a virus, but they do intriuge me.

Yes.

It can be destroyed, it replicates itself, it requires specific abiotic conditions to replicate, it requires specific abiotic conditions for it to live, and it consumes materials. The fact that the conditions it requires are, say, human red blood cells doesn't mean it's not alive, rather, it means that it is alive on a scale that we find hard to comprehend.

 

[Darkwater]

Ask any scourge they shall tell you it is alive as it ploughs it's course from void through the food chain to wherever via who or what ever..

It starts as search & destroy heatseeker once intelligent,& spreads from cycle to cycle if it is any good or newly evolved.

Like everything else,it's drive & ambition generates the energy to *be* or otherwise.

Same as light(darkness illuminated)