Are Viruses Alive?

slipss

Maybe some biology students or doctor or something would be able to awnser this for me, are viruses considered living things? I think I was thought in school that they were, but since then I've heard a few places that they aren't, something to do with the fact that outside of a host viruses can't function, but if that was the case wouldn't fungi be considered not alive aswell? Also do viruses carry out the seven life processes, ye know respiration, reproduction, I can't think of the rest of them, I dunno what got me thinking about it, but I checked a few sites on the net and kept getting conflicting awnsers, so hopefully someone can give me the generally accepted fact on this, thanks.

craig17

the main thing to be alive is that u have to be afraid of death at some point and a virus is more of an reaction that can look like life but it is just the way it is a virus

they are technically not alive!I think it is because dont have a nucleus.

Capt'n Midnight

Deleted User wrote:

they are technically not alive!I think it is because dont have a nucleus.

Neither do most of the living organisms on the planet

Anyone know if viruses are bits of degenerate DNA/RNA fragments or if they are parasites that have dropped redundant features ?

If they originated as fragments of DNA then I wouldn't call them living since they are only an accidental fraction. If the ancestor was a free living organism that fulfilled the seven characteristics of life then they'd have a better chance of being defined as life. But it's a grey area, well not that grey since if you created a third category for "semi living" viruses there would be very little confusion as to where to categorise them. The problem is only if you try to put them in to either other category.

Some enzymes can be made from RNA. Early organisms probably used RNA for genetic material and possibly for enzymes too. Its unlikely that some viruses are left overs from the organic soup of RNA self replicating molecules.

John

slipss wrote:

something to do with the fact that outside of a host viruses can't function, but if that was the case wouldn't fungi be considered not alive aswell?

Fungi are very much living. Not all fungi are parasites.

Personally I class viruses in the living spectrum of things. I think once an organism is replicating DNA/RNA it is essentially alive. Although then there are prions which are proteins which replicate themselves. Hmmmm.

Sleipnir

craig17 wrote:

the main thing to be alive is that u have to be afraid of death at some point

So things like grass or woodlice sometimes lie awake at night worrying about nuclear war and cancer?

John

Sleipnir wrote:

So things like grass or woodlice sometimes lie awake at night worrying about nuclear war and cancer?

Of course they do. My lawn is usually more upset at the thoughts of it dying and not having prepared a proper will.

Shazbot

Deleted User wrote:

they are technically not alive!I think it is because dont have a nucleus.

So do a vast amount of microbes and they are very much alive. Infact there is a whole kingdom designated to prokaryotes.

As for virus' , it's an ongoing debate. Even the proffesionals are undecieded as they don't display the characteritics of live untill they find a host.

god i do biology in college.maths has me mind frazzled.i actually looked over it in notes today.In my opinion, i wouldnt consider it "living"

senordingdong

Googlefight could sort this.

Shazbot

senordingdong wrote:

Googlefight could sort this.

yea because googlefight is such a well respected microbiologist. :rolleyes: I taught this would be an interesting topic to discuss untill i saw this comment.

Personally i think they are both living and death. A strange statement i know but they don't display any characteristics of life but once they attach to a host they do. They reproduce , adapt , organise , metabolise , grow and respond to stimuli.

GuanYin

Its a divided topic depending on what way you approach it from.

Generally speaking if you approach it from the more philsophical point of view and cite issues such as self-awareness etc for life, then viruses wouldn't qualify. Then again, neither might several other cellular organisms or for that matter, severe cases like patients who were brain-dead.

If you take a more simple definition then viruses certainly exhibit many characteristics we would associate with life. They reproduce, respond to stimuli and adapt to their environment. Although they don't have a metabolism of their own, they act as an intracellular parasite to complete their life-cycle.

They also are far more than just "a disease" and act as an important part of any eco-system and as an evolutionary pressure source. Life may not have evolved as it has, or at all, but for viruses.

Personally, I'd be more inclined to stay away from the philosophical aspects of the debate and stick to the biological ones and as such I'd qualify them as simple life.

Tree

Capt'n Midnight wrote:

Anyone know if viruses are bits of degenerate DNA/RNA fragments or if they are parasites that have dropped redundant features ?

a little from column a and a little from column b. There are various classes of viruses that started as random bits, and others that drop stuff, (very simple starting out parasites though)

I dont think viruses are alive. They dont carry out their own life function. Though i think the giant mimivirus might do summat crazy that others dont (it's a HUGE virus, bigger than E.coli, its a parasite of some protazoan or something.)

they dont diisplay all the characteristics of being alive.

Capt'n Midnight

Elytron wrote:

There should be a poll.

Only the living should be allowed vote.

Panserborn

Back in my undergrad years we were told catagorically that there were non-living. Bacteria, we were told, were the lowest form of cellular life and viruses were essentailly inert bio-particles. I tend to agree.

wheresthebeef

yeah we had our microbiology lecture series from one of the head honchos in Pathology at St. James Hospital, and he said Viruses and Prions were non living.

GuanYin

Prions and Viruses are very different and it is erroneous to catagorize them together at all in this regard.

DrIndy

Viruses are incapable of independent reproduction and therefore are classed as non-living in the purest sense, however, they can reproduce with the aid of another cell so are in fact alive.

wheresthebeef

psi wrote:

Prions and Viruses are very different and it is erroneous to catagorize them together at all in this regard.

I didn't say they were anything alike, other than that some dude told us neither was a living organism, obviously this is further qualified by indy - "in the purest sense".
So, in the purest sense, they are not alive. I'd be inclined to go with the purest definition. Although obviously its a matter which is subject to lots of debate and some interpretation.

Panserborn

DrIndy wrote:

Viruses are incapable of independent reproduction and therefore are classed as non-living in the purest sense, however, they can reproduce with the aid of another cell so are in fact alive.

In terms of cell biology there are inert and non-living. However, as metioned in the above quote, they can reproduce at some level. With this in mind they could probably be classed as a replicator (as defined by Dawkins á la the Selfish Gene theory) and so show life-like properties, but they are never truely alive.

Chucky

Is anything really alive at all? I'd question whether even humans have actual choice in things we do, let alone viruses. A human is a collection of many different organisms all neatly wrapped up (like a city or something). I believe that every single thing that happens in the universe happens in certain ways that COULD be predicted.


...and don't cite the Uncertainty Principle! ...Pleasssseeeee?

John

Chucky wrote:

Is anything really alive at all?

Under the definition of living, yes there are lots of things that are alive. Does that make us any more special than non-living matter? No, just more interesting.

I'd question whether even humans have actual choice in things we do, let alone viruses.

Who says living is about choice?

A human is a collection of many different organisms all neatly wrapped up (like a city or something).

If you look at each cell as being a separate living organism, I can see you're point but I don't agree with it

I believe that every single thing that happens in the universe happens in certain ways that COULD be predicted.

Aren't physicists always blathering on about the great theory of everything. I believe there is a formula out there that will predict the outcome of any given situation but that's far beyond what we'll ever understand.

Chucky

John2 wrote:

Aren't physicists always blathering on about the great theory of everything. I believe there is a formula out there that will predict the outcome of any given situation but that's far beyond what we'll ever understand.

Your whole answer was very agreeable to me - Thank you! I'm also overjoyed that you too think that there is a formula that could pedict the outcome of every event. As you said though, it is well beyond us at this moment in time.

John

I don't think it's beyond us just at this moment in time, I think it's beyond us full stop.

Panserborn

Chucky wrote:

Is anything really alive at all? I'd question whether even humans have actual choice in things we do, let alone viruses.

...and don't cite the Uncertainty Principle! ...Pleasssseeeee?

I won't cite the Uncertainty Principle but I will cite the Meme Theory (Susan Blackmore and Dawkins), I don't fully agree with it but if you're into the question of if we have actual choice and freewill it makes interesting reading.

Chucky

Thank you for that - I now have a new muse (Memetics)

senordingdong

Don't we already ahve one Elytron...aren't 'non-living' and 'inanimate' different words in that respect?

Tree

Elytron wrote:

If viruses are not alive i think we need a new defintion of non-alive.

non-alive - not being alive, tis one of them things defined by what it is not

Chucky

How can you possibly think that they are not alive? They are just parasites but on a much smaller scale than say, the Liver-Fluke.

r3nu4l

OK, a virus cannot survive outside it's host - in other words, cannot survive outside it's comfort zone and specialized conditions allowing it to exist.

Humans cannot survive underwater (breathing aparatus aside!) - outside their specialized conditions.

So in that sense, if humans are life forms, then so are viruses.

Some people say that DNA/RNA is the lifeform and that everything else is just immaterial - depressing thought!

Others say that only whe there is a cell is there truly a life form.

As someone already said, it is all still very much under debate as is the prion issue (that's for another day!).

IMO (and it's all that matters to me because I'm feeling very arrogant today ) viruses are alive, they reproduce well in a host and constantly evolve. That's enough for me.

Capt'n Midnight

r3nu4l wrote:

OK, a virus cannot survive outside it's host - in other words, cannot survive outside it's comfort zone and specialized conditions allowing it to exist.

A virus can't replicate outside it's host. So as long as it isn't attacked by UV or enzymes or other conditions its specialised conditions can range from 0K to 350K, from vacuum to GigaPascals, most solvents, many biocides etc. etc. And many viruses can be crystalised so comfort zone is kinda meaningless.

Humans cannot survive underwater (breathing aparatus aside!) - outside their specialized conditions.

neither can diamonds or galaxies

Some people say that DNA/RNA is the lifeform and that everything else is just immaterial - depressing thought!

life is just nucleic acids way of making more nucleic acid.


All you need to do is have a separate category for self replicating molecules that assemble simplier components in a single stage. I'd include some of those double membrane liposomes in the category too. Possibly Von Neumann machines too. You can split hairs forever as to which side of the living/non-living divide they are on. But self replicating bio molecules can't be considered dead and inert or even as catalysts. Likewise they fall far short of even the simpliest living thing that meets all seven classic characteristics of life.

It's like asking if water is a solid or a gas, in a universe where free flowing liquids are rare.

senordingdong

Well is someone gonna answer my question or what?

r3nu4l

Capt'n Midnight wrote:

A virus can't replicate outside it's host. So as long as it isn't attacked by UV or enzymes or other conditions its specialised conditions can range from 0K to 350K, from vacuum to GigaPascals, most solvents, many biocides etc. etc. And many viruses can be crystalised so comfort zone is kinda meaningless.

neither can diamonds or galaxies

life is just nucleic acids way of making more nucleic acid.


All you need to do is have a separate category for self replicating molecules that assemble simplier components in a single stage. I'd include some of those double membrane liposomes in the category too. Possibly Von Neumann machines too. You can split hairs forever as to which side of the living/non-living divide they are on. But self replicating bio molecules can't be considered dead and inert or even as catalysts. Likewise they fall far short of even the simpliest living thing that meets all seven classic characteristics of life.

It's like asking if water is a solid or a gas, in a universe where free flowing liquids are rare.

note: "comfort zone" is a typical lab scientist term and not an official biological term.
I meant "Comfort zone" to be specific to each individual species (not a general comfort zone for all virii) e.g. baculovirus survive happily inside but not outside of specialized tissue culture cells called Sf9 or Sf21 and nowhere else.

Also, Parvovirus cannot survive in Sf9 or Sf21 cells but survive quite well in dogs (unless it is parvovirus strain B19, which survives well in pregnant female humans and causes miscarriage ).

All conditions (temp, pressure, chemical constitution etc) specific to a virus and it's host cells are the "comfort zone". Each species of virus has different conditions - example HIV cannot survive outside it's specialised conditions, presence of human CD4+ T-cells etc.etc. etc...

Erm, what is your point about galaxies and diamonds?? :rolleyes: Lots of things can't survive underwater, I chose to demonstrate a certain set of specialised conditions outside of which humans cannot survive as a sort of analogy for the specialised conditions outside of which a virus cannot survive. It was an illustration that non-scientists (hopefully) can understand. The rule is, always begin simple and build up (don't start by trying to show off your knowledge, that's not educating, that's for the arrogant!)

"life is just nucleic acids way of making more nucleic acids" - hee hee I'd like to see you try and say that at certain symposia at the International Plasma Protein Congress - you woudn't last two seconds!! - that said, I'm in agreement with you here Cap'n but it's still a depressing notion philosophically - I'm saying this and I have a PhD in Molecular Biology and viral diagnostics!!!

Senordingdong - as any scientist who works in a lab will tell you, definitions change all the time! Non-living and inanimate are different terms, yes, but new research and discoveries will always add to these terms!

Tar.Aldarion

John2 wrote:

Aren't physicists always blathering on about the great theory of everything. I believe there is a formula out there that will predict the outcome of any given situation but that's far beyond what we'll ever understand.

Sure physicists never stop talking about it.
A theory of everything is a theory of theoretical physics and mathematics that fully explains and links together the four known forces under one unifying theory. It doesn't explain everything like that.
Einstein was the original founder of a Theory of everything. He believed that the only task was to unify general relativity and electromagnetism. He wanted to unify the four forces: gravity, the strong nuclear force, the weak nuclear force, and the electromagnetic force, which was at the time, a unification of the electric and magnetic forces by James Clerk Maxwell in 1865; it should also explain the spectrum of elementary particles.
The problem is the theorized graviton has still unproven. This missing piece in a theory of everything involves combining quantum mechanics and general relativity into a theory of quantum gravity. There are places built by NASA and other organisations around the world looking for gravitons and it is not beyond our capability, most likely, to find them if they exist. Things like physics and super symmetry make me oddly happy. Let's hope N=1 eh. :P


The thing you speak of where we can predict every is quite different...



As for the answer to this thread, it depends on your definition of life.

John

Ah, thanks for clearing that up for me Tar, I'm far more of a physiologist than a physicist.

Tar.Aldarion

That's one out of two, better than my number!

You know when a bactiophage(virus) joins with a bacterium chromosome!Is it still a bacteria(in the rare case where lysis doesnt occur.Is this still a bacteria?

DrIndy

not techincally, its a virus infected bacteria!