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Viruses Infected By Viruses
SpaceAdmiral writes "Scientists have discovered a virus that can infect another virus. The fact that viruses can essentially get sick may change the debate over whether they are alive or not. Check out Nature for a slightly more technical article about the 'virophage.'"
How long till these things are linked to stuff like cancer?
_ _ _ Go for the eyes Boo! GO FOR THE EYES!
We call it 3 stooges syndrome and Mr. Burns has it.
I'm pretty sure they can reproduce, else there would be no risk of spreading them and they'd all die out soon after coming into being.
"The fact that viruses can essentially get sick may change the debate over whether they are alive or not."
Ya ... to the debate over whether the viruses that make the viruses sick are alive or not.
The reason your school taught you that is because the definition of living usually taught in schools includes such characteristics as:
just to name a few. Viruses don't possess any metabolic function (they use the host cells hijacked machinery), they don't grow (once created, they are essentially static objects until they bump into a cell), and they have no means of independent reproduction (again, the hijacked cells reproduce the virus).
On the other hand, many people simplify the definition of life to solely the ability to reproduce (independently or not), which makes viruses alive, but also makes prions alive, and makes it fairly easy for humans to "create life" in the form of self-reproducing machines.
$_ = "wftedskaebjgdpjgidbsmnjgcdwatb"; tr/a-z/oh, turtleneck Phrase Jar!/; print
Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum,
And the great fleas themselves, in turn, have greater fleas to go on,
While these again have greater still, and greater still, and so on.
- Augustus de Morgan, A Budget of Paradoxes
While I haven't heard of a virus hijacking another virus, I have heard of researchers hijacking viruses to do good things.
That's pretty much why viruses aren't considered alive, as they only propagate by hijacking living organisms' replication machinery. Eunuchs are individuals, that the definition of life applies to species, not individuals. Mules can occasionally reproduce, but is rare and it's due to the unequal distribution of chromosomes in meiosis. This isn't why they would be consider alive, they are the offspring of organisms that are alive. It's just an anomaly of nature. All viruses are parasites that depend on a host's replicating machinery by definition, therefore cannot be considered living.
you must be one of those students who are learning to write viruses...
No, they are not alive even if they can get sick. Viruses, even infected ones, cannot self-replicate as they require the use of a host and host machinery. If you can find me a self-templating virus, then we'd have an interesting discussion...
viruses infecting viruses is still cool though.
-Ryan
AUWYHSTOT (Acronyms are Useless When You Have to Spell Them Out Too)
Obligatory link to an old paper: Eugene H. Spafford. Computer viruses as artificial life. Artificial Life, 1(3):249-265, 1994.
The short answer is "no," but it makes for an interesting read if you have some whiskey to drink while you're reading it.
You should look into what shit is made out of.
Nerd rage is the funniest rage.
For the debate over whether viruses are "alive" to make any sense, there has to be some literally essential difference between things that are alive and things that are not. The past 200 years or so of biology ought to have taught us that, contrary to what seemed evident to the ancients, there isn't any such essential difference. Organic matter is just a form of organization of inorganic manner. From the point of view of what the ancients knew, there was a huge gulf between everyday living beings and inert objects. From the point of view of what we know, there are many intermediate cases.
So, instead of wasting time trying to decide whether viruses are "really" alive or not, you should just accept the fact that our knowledge today is advanced enough to show that the question--which we inherited from people who knew less than we do--is flawed.
Are you adequate?
So a virus that attacks viruses eh? I wonder if there a virus that attacks the virus that attacks the viruses? And a virus that attacks the virus that attacks the virus that...er...well, you know what I mean. And what if the first virus evolves to attack the last virus....every time you get one of those mysterious unidentified itches it could just be a ring of viruses all chasing each other around in circles!
I like my coffee the way I like my women - roasted and ground up into little tiny pieces.
The local phone book makes an interesting read if that's the excuse you need to relax with some good whikey
To me, the issue of how to define "life" is only a small side note to this discovery.
Far more important are the consequences for medicine. Viruses can be attacked by other viruses. This is huge. Compared to bacteria, viruses have been very difficult to beat. Infectious bacteria can be combated by using anti-biotics, bacterio-phages and other means. Whereas viruses are significantly more hardy, and combating them directly is difficult. But this discovery opens the door to engineering virophages to attack viruses in our bodies that make us sick.
I will accept nothing less than slashdot comments to read with my fine whisky.
saying something is "alive" or "not alive" holds about as much weight as saying it's a "froodle doo". if the definition is standardized it should be easy to define: if not, what does it matter what we call it as long as we know what it does? attempting to apply terms that apply well to one group, from species to kingdom, to another group almost always ends in failure for this reason.
shame on the virologist for perpetuating this craziness. the real cool part about this finding is its possible medical applications.
makes it fairly easy for humans to "create life" in the form of self-reproducing machines.
What's so easy about that? It's never been done! It would be a stupendous thing if it were.
Summary is totally misleading. The story isn't about viruses "getting sick" - it's about a certain type of satellite virus (not new) that can only infect a host that is already infected by another virus. Essentially the satellite virus is competing with the original virus for metabolites. The discovery here is that for the first time a satellite virus is competing for these resources to such an extent that it is actually destroying the original virus.
Making you think you're crazy is a billion dollar industry.
Is a mule alive? It can't reproduce. Maybe you object because the mule is *made* of cells, each of which can reproduce, but your body is full of cells that can't reproduce, are they alive? What's reproduction got to do with being alive anyway? If you take a cell that can reproduce and mutate the gene that produces a necessary protein for the reproductive process, is the cell now dead? It can still metabolize, make other proteins and interact with its environment. When it no longer can, that's when we say it is dead. As such "living" already has a good definition, even if it isn't too strict, and that is the opposite of dead or, more precisely, "inert". Viruses are not just a package of DNA, (or RNA), they're also a system of proteins for delivering that package from cell to cell. A virus most definitely isn't "inert" in the same sense that a "dead" thing is. So if something isn't dead, what is it? Undead? We typically reserve that word for horror writers, and just say "alive".
I think the objectionable aspect of calling viruses "alive" comes from people thinking of viruses as "pure information", they're not. They're complex machines that can cause their own replication in their environment. Their environment just happens to be living cells, which are also complex machines that can cause their own replication in their environment.. To accept that a virus isn't alive because it needs its environment means you have to accept that a cell that requires a water environment isn't alive, or all multi-cellular organisms are not alive. Are mitochondria alive? Are the cells that require mitochondria alive? How about yeast? How about that mule?
How we know is more important than what we know.
What about computer viruses and worms? Some people argue that those are life, especially worms which are able to reproduce in their environment independently without a host.
Tomato wedge sperm darts that are Republican.
I recall some reading about testing (I'm guessing a year or so ago) about the use of the virus in fighting cancer. I can't find the exact article in question but I did find this.
Cancer-fighting virus shows promise in early clinical trial:
http://www.physorg.com/news103082669.html
The virus, called NV1020, is a type of herpes simplex virus modified so that it selectively replicates in virus cells, killing them in the process.
This was in July of 2007 it would seem.
"So long and thanks for all the fish."
What about computer viruses and worms?
TaDa! This just in from Science Daily:
http://www.sciencedaily.com/releases/2008/08/080806194601.htm
OH.. Oh.. ohhh.. ok. I read the headline and I said "Man! Again, another article about Windows Vista!"
Kidding!
Somewhere in the world a grammar nazi just had a stroke at their keyboard.
http://projectleader.wordpress.com
Yes. Mules cannot reproduce. The distinctions between species are based on the production of offspring which can reproduce to the nth generation.
I used to carry a bottle of whiskey for snake bite. And two snakes. -Nefarious Wheel
Our definition of 'alive' is flawed. Virii, plasmids, prions, etc. are not alive, but they aren't just arrangements of molecules either. They're in some sort of limbo.
Add to that the fact that this doesn't seem to infect other viruses, just uses a specific MHCI protein as a binding site that happens to be produced by another virus. In which case it's not that interesting.
This is more interesting in and of itself than it is to 'our belief of what life is' or something. We've known that 'life' is a pretty flaky definition for a while now.
I have developed a truly marvelous proof of this comment, which this signature is too narrow to contain.
Hell, fire's 'alive' by that definition. As long as it's got fuel, it metabolizes fuel, it physically grows as time goes on, and often, one flame will split into two when the fuel in the middle runs out. Yes, I know there's more to it than that, but I'm just pointing out that we've gotta be careful about how we define life, or else we run into a few problems we aren't anticipating.
Am I the only one that thinks that they replicate by way of using the the host tissue cells by tricking it to make duplicates?
Just to be clear, what I listed was only a subset of the definition. If you want a more formal definition, there is a decent one here: http://en.wikipedia.org/wiki/Life#Definitions
Fire for instance, fails on homeostasis (no regulation of state to maintain equilibrium), organization (no cell structure; while I don't think we should require cellular structure, you do need some organizational principle), and no adaptation.
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Because the statement that A = A is tautological, but the statement that A = B is not. The truth of the former conveys no information, but the truth of the latter does. To put it like Frege puts it, "The morning star is the morning star" is a trivial statement, but "The morning star is an evening star" is an astronomical discovery.
Whiskey is the crap left over when all the whisky is gone.
No more Laphroaig? Powers'll do ya.
$
All viruses are parasites that depend on a host's replicating machinery by definition, therefore cannot be considered living.
Don't all 'higher' animals begin life essentially as a parasite within the mother? Now granted, its the same species in this scenario, but it's still something to think about.
What about fungi? They are considered organisms and alive, yet they grow as a parasite in or on a living host or other form of organic matter, and cannot grow or reproduce without said host. That's not too far off from how a virus reproduces. True, fungal reproduction does begin within the cells of the fungus itself, but the line really isn't as clear as many would think.
On that note, no life form truly reproduces autonomously; the chemicals that life is formed of are created/encoded from outside materials. Animals take in these outside materials by eating, plants draw them from the ground, fungi from the aforementioned host/organic matter.
That said, It is true that when viruses replicate, the 'parent' virus does not take in material to reproduce (and rather, as mentioned, hijacks the host cells systems to do so). As important as that distinction may sound, I believe that when compared to how 'true' life forms reproduce, it seems mainly a question of semantics. It's a tough call, I guess all that can be said is that viruses certainly define the term 'gray area...'
Any definition of life doesn't make everyone happy because life is subjective. Life exists on a scale where at one end we all agree its not alive, and on the other we all agree it is alive - however just drawing a line somewhere in between and saying from here on in its 'alive' is pointless.
The same issue occurs when trying to define where one species stops and another starts in animals.
Control is an illusion, order our comforting lie. From chaos, through chaos, into chaos we fly
Tricking to reproduce? Humans have been done this for ages.
Don't fight for your country, if your country does not fight for you.
It's the same thing with planets and Pluto; early in school you need simple classifications. Unfortunately, some people will never really outgrow this level and continue to need them throughout their lives.
Religion is what happens when nature strikes and groupthink goes wrong.
GGGP
In other words until their code(DNA) is executed. Same definition applies.
America, Home of the Brave.
Great-great-grandparent post.
Tomato wedge sperm darts that are Republican.
See Ring species - species boundaries are not as clear cut as your definition would have them, though that's a good rule of thumb.
There are many arguments over how to define species - Morphological differences (which in practice is often the starting point), Biological differences, Shared ancestry etc.
the noise you make when a heavy concept lands on your toe, especially when your feet are cold.
The revolution will not be televised... but it will have a page on Wikipedia
Not if they don't believe in evolution.
The revolution will not be televised... but it will have a page on Wikipedia
virii
Viruses. Virii would imply the latin word, which described a liquid like substance. As we know, liquid has quantity, not quantities, therefore is not pluralised (eg, four pints of water, or four water pints. We see the quantity is pluralised, not the substance).
Understanding what viruses actually are came a long time after latin became a dead language, and so the pluralisation occured in our modern languages, while the pluralisation in latin continues to make no sense.
The revolution will not be televised... but it will have a page on Wikipedia
which of course brings us to the conclusion that mules are sometimes (rarely) alive
so sex is a viral meme?
"There is a way that seems right to a man, but its end is the way of death." Proverbs 16:25 (NKJV)
I've thought about this recently, too. It of course depends on how you define life. I think astrobiology is usually a good resource for definitions of this sort. If we found a virus on mars, would we say we discovered life? I think so. I like Carl Sagan's definition: "Living systems might then be defined as localized regions where there is a continuous increase in order." This is important to note, as the universe generally increases in entropy. At the center of all life we know is information. Information that replicates itself in some manner, as books are clearly not alive. So it would seem information (increase in order) and replication in some manner. So could a computer virus fit the definition? Conceivably.
Don't all 'higher' animals begin life essentially as a parasite within the mother? Now granted, its the same species in this scenario, but it's still something to think about.
A living individual animal only lasts for X amount of years. The level of importance is down to the gene, not really at the individual, but the individual will try to spread as much of its genes as it can to the next generation. This is a lot harder to do with females than with males, because females are typically stuck with the job of raising the kid, costing both resources and energy.
The fetus under development is not a parasite, because the benefit of the host is to pass on its genes to yet another generation.
What about fungi? They are considered organisms and alive, yet they grow as a parasite in or on a living host or other form of organic matter, and cannot grow or reproduce without said host. That's not too far off from how a virus reproduces. True, fungal reproduction does begin within the cells of the fungus itself, but the line really isn't as clear as many would think.
We all need some kind of resources to survive, but we have replicating machinery that viruses do not. Fungi have this replicating machinery, and much of what is understood about the replication machinery in eukaryotes comes from the S. cerevisiae, a fungi. It doesn't matter if an organisms is living on a host to leech off of some of the host's resources such as nutrients. We all get our nutrients externally. Viruses can't even replicate without hijacking the machinery of another organism. That's really neat, but that doesn't quite make them alive.
On that note, no life form truly reproduces autonomously; the chemicals that life is formed of are created/encoded from outside materials. Animals take in these outside materials by eating, plants draw them from the ground, fungi from the aforementioned host/organic matter.
That said, It is true that when viruses replicate, the 'parent' virus does not take in material to reproduce (and rather, as mentioned, hijacks the host cells systems to do so). As important as that distinction may sound, I believe that when compared to how 'true' life forms reproduce, it seems mainly a question of semantics. It's a tough call, I guess all that can be said is that viruses certainly define the term 'gray area...'
It's not really an issue of semantics if you consider how important it is for an organism to be able to replicate itself. It's one of the basic things of being alive, probably the most basic.