Are Viruses Alive?

FZ+

Well then, are they or are they not?

Imparcticle

I chose "other".

FZ+:
"alive" must first be defined to accurately reply to this question.

Do viruses have hereditary material? That is a common definition of "alive".

Jake

Yes exactly, what defines "alive".

Viruses are what they are. If alive is just being able to reproduce, then viruses are alive. If alive means consuming energy and being proactive (IE growth, movement) then nope, not alive

Often the debates about wether a virus is alive or not is really a debate about what constitutes "alive", without the participants even knowing it

selfAdjoint

Alive involves movement, metabolism and reproduction. One-celled animals like prokariotes do these things on their own. Viruses have no metabolism and their reproduction depends on the structures of the cells they prey upon. Some of them do move independently.

So I put NOT. The other category seems a cop-out; clearly even very simple bacteria are alive, and also clearly viruses don't do - independently - all the things a linving organism is assumed to.

Les Sleeth

What he said . . . no way.

It's a bit of programming that can take advantage of a living cell.

chroot

Some people have theorized that viruses were developed by some ancient form of bacteria as a weapon against other bacteria. I don't know the current scientific validity of that theory, but it makes sense. Something living (and with RNA at least) had to make the first virus, since it couldn't have made itself. If you don't believe that a bullet or a missile is alive, then neither is a virus.

- Warren

photon

You know they're alive after you've lived with a couple for a few years.

Of course, this assumtion would imply that all windows computers are alive. So that won't work dagit!

Les Sleeth

Interesting idea, sort of like venom. Looking at it on the constructive side, I have wondered if viruses might be genetic remnants left over from early single cell diversification.

olde drunk

if you can tell me a usefull purpose, reason for knowing i'll think about it.

otherwise, i don't care.

peace,

selfAdjoint

olde, it's interesting to see that the definition of "life" has some questions in it, contrqry to what might naively be presumed. It's always good to ground a high flying discussion in the real world, don't you think?

olde drunk

the world is full of impounderables. i'll invest time and energy with those that either expand my awareness or improve my life.

a pragmatic seeker? guilty!
peace,

Rader

Why not; is anything dead.

Or do things just change there physical states?

How much much more "dead or alive" is that oxigen molecule, that the "dead or alive" virus swallowed?

Jeebus

The question poses too much definition in terms, I suppose. No one here is going to agree 100% of what alive, dead, or neither actually consists and constitutes of.

Les Sleeth

There is general consensus that life is a self-sustaining sytem that metabolizes, multiplies, and has the ability to evolve. Because technically it can be said that a fire, for example, metabolizes and multiplies, I like the delimiter John Maynard Smith and Eors Szathmanry gave in their book "The Origins of Life." They said we might define as living ". . . any population of entities possessing those properties that are needed if the population is to evolve by natural selection. That is, entities are alive if they have the properties of multiplication, variation, and heredity (or are descended from such entities; a mule cannot multiply, but its parents did). . . . Why should we regard these three particular porperties as defining life? It is because they are necessary if a population is to evolve all the other characteristic we associate with life."

A virus, by even less of a definition than that, fails to show it is alive. Left on its own, it will not multipy, it will not variate (constructively), and of course it will not pass on genetic material. It can do nothing until it enters a living system, which then merely reproduces the virus and reacts to the virus. True, the virus can mutate, but it can only do that once it enters the living system. Remember, the genetic material of a virus came from formerly living cells, so we shouldn't be surprised that programmed into it is an adaptive trigger. Because a virus cannot mutate on its own, we have to assume it is the living system itself which is providing the impetus to pull that trigger.

A virus is not alive!

Loren Booda

Viruses are biological uncertainty.

Loren Booda

In biology, the only certainties are death and taxis.

FZ+

Shh! Redefine the question, if you want, to include the phrase: According to your personal concept of life...

You see, I have a problem with this argument. Nothing does all the things a living organism is presumed to, independently. Plants need sunlight, for example. Humans need to eat. Animals usually need females, or males. Why can't we say that viruses are living carnivores, which feed on uninfected cells and digest them to function?