What viruses "want" is to reproduce. Killing you is an unfortunate unplanned side effect.
If only we could negotiate and agree to allow them to reproduce and not kill us, we'd all get along much better.
If only we could negotiate and agree to allow them to reproduce and not kill us, we'd all get along much better.
You need very strong group selection to restrain breeding, and this becomes less and less likely as the population size increases (so each individual has less and less affect.) See The Tradgedy of Group Selectionism: http://lesswrong.com/lw/kw/the_tragedy_of_group_selectionism...
Even when organisms are selectively breed by scientists with group selection to limit their population size, they often just become cannibalistic rather than restrain their own reproduction. Killing someone else's kids is better than killing your own.
Essentially the same thing happens with viruses, where over reproduction means killing all the hosts cells.
EBV latently persists in the individual's B cells for the rest of the individual's life [1]
An interesting tidbit from xkcd's "What If" series: individual cell mortality from viruses in the oceans is about 20% per day.
http://www.reddit.com/r/dredmorbius/comments/1vyanj/viral_so...
Jared Diamond has offered related observations on pathogens and parasites in tropical vs. temperate climates. It strikes me that an ecosystem in which there are periodic resets (e.g., killing winter frosts, or long summer droughts) offer a more amenable set of living conditions to those species not affected by those resets, whether by adaptation or technology.
Also, I don't think "benign" virus compete with pathogenic virus for anything. This may seem strange, but unless the organism is completely shutting down, and probably not even then, only an extremely small fraction of cells are infected by any one virus. That's why you still have a nose after surviving the flu. Any competitive mechanisms would have to be more complicated.
That is to say, "Don't negotiate with terrorists."
Fortunately the human/mammalian immune system does not typically permit this kind of deal. With a few exceptions: including HIV.
Sure, but killing the host is not generally the goal of a pathogen. Killing the host typically means the pathogen won't spread any further, and that direction leads to the pathogen's extinction. Or, the death of this family line, if you like.
But, before worrying about that, if a virus does not address the immune system, it will not be able to spread at all - there will be no family line. The initial goal of a new virus is to evade the (highly advanced) immune system.
Ebola apparently has a very naive way of bypassing the human immune system. That is, overwhelm the system, so that the host dies, but you have a small chance of spreading. This works, sometimes, for a little while, but not too much, maybe just enough to gain a few generations of evolution to try and improve your strategy. If you are already a latent virus in a related species, you might get a few attempts at this, as Ebola has.
HIV does this in a frighteningly more effective way - a way which is more evolved - hide from the immune system while maintaining a route to spread to other hosts. This has to be a very subtle balance - hiding from the immune system is no mean feat. This is why I used HIV as an example - HIV somehow negotiates its own and the host's survival with the immune system (where Ebola has not been able to).
The dance between immune system and virus ultimately leads to AIDS. Death of the host is not ideal for the local strain of HIV, but it had a good chance to reproduce in other hosts, so it's a good result for HIV as a whole.
To become an effective and latent human virus, you need to evolve some sympathetic way of defeating the immune system that doesn't have a significantly negative result for the host. It's likely that HIV is still on that path, and Ebola might be on the start of that path.
This is why we observe viruses to become less deadly and more easily spread over time.
It's not necessarily true that this is the only evolutionary path, but the immune system presents such a huge barrier that you have to overcome this before meeting any secondary goals.
Ebola virus is successful at spreading due to the fact that it's in various fluids secreted by endothelial cells (which are everywhere in the body). The virus has mutated to let those tissues start to "leak", which means a person infected with Ebola is more likely to leak fluids (which is why it sometimes causes bleeding out of mucous membranes). Since there is an increase in the endothelial fluids released, there is more exposure to those trying to treat a patient with Ebola.[1]
The way the virus spreads (increased discharge of endothelial fluids) is what causes it to be so fatal, which is a by-product.
[1] Great overview of the virus: http://arstechnica.com/science/2014/11/understanding-the-ebo...
The plague/black death/Y pestis is another is a great example of this. It keeps its rat host just alive enough for just long enough for maximum use of the rats body. The rat then dies, which sends sends it plague-ridden fleas off to infect other rats.
It seems that the Black Death was pneumonic as well as bubonic.
this work is being done with bacteria, not sure it is possible with viruses though.
Either you live at least long enough to spread the virus a little bit, and you vote that what the virus is doing is good, or you die before spreading, and you vote what the virus is doing is bad.
Let's get voting !
Having to wait for things to die can be restrictive (but genomes are declarative, what does that buy?). Roughly, with what amounts to the assumption that Lamarckian evolution is more or less not true, you can characterize evolution's learning power as almost as good as PAC (query: statistical query learning evolution).
See alsos:
http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/601.htm...
http://arxiv.org/abs/1211.4037: Natural selection. V. How to read the fundamental equations of evolutionary change in terms of information theory
1. You're right, our intelligence is the same thing. Intellect is a statistical creation that makes us good at surviving.
2. But usually, when people talk about our intelligence and our having goals, they aren't talking about the fact that we statistically exhibit tendencies towards self-preservation (which is what we're talking about viruses doing). It's that we literally have conceptual goals, which can be written down ahead of time and talked about.
aka you won't find a virus with a to-do list. Conflating that intelligence with viral 'intelligence' is kinda disingeuous.
--
That said, I do agree that we might/will find alien life that looks nothing like what we expect and has 'intelligence', for some reasonable (non-virus) definition.
I would not be inordinately surprised if we managed to find this in the motion of waves in the ocean, or in the swirling gases of the sun, or the gravitational interactions of the asteroid belt, or in tremors in the earth, or in hive-minds of billions of ants. And I definitely reject dualism and fully expect that a human brain simulated in a computer would be as intelligent as we are.
I'm not sure what the criteria for an 'intelligence medium' is, but it seems to require sufficiently high entropy to allow for complex patterns to form, but not too high - there has to be enough order and especially a not-too-high temperature such that self-contained systems can form and replicate without being blurred back into the whole system.
However, they do reproduce, just like pretty much every other form of life. The question of why life does that is closely related to the question of what life is and how it came to exist. Those are deep questions and we don't really have a clue as to the answer right now. There's certainly nothing in the fundamental physical laws of the universe, as we understand them today, that seems to indicate or require the existence of life.
OMG What if we're the cancer of the universe, who is in itself a giant amoeba!??!!?!?!?
deep thoughts, with jack handy
Sometimes in half-seriousness we say that man may have been evolved by the system as a mechanism to get the fossil fuels and other minerals back into circulation. We hope he is pre-adapted for other roles after that.
From Environment, Power, and Society.
An analog I use is to opportunistic benthic whale fall communities. The emerge and develop rapidly. They do not sustain.
As to why our universe is one which supports life, nobody really knows. Some invoke the anthropic principle, but that is more of a philosophical answer than a scientific one.
There's an implicit distinction in this statement, between the universe and life. Really, life is part of the universe too.
I'm familiar with the anthropic principle, but it doesn't tell us whether life is a necessary outcome of the physical laws of our universe, or whether it's just one of many accidental outcomes that are not forbidden by the laws of our universe. Both of those situations satisfy the anthropic principle, but are very different.
For example, we could speculate about a universe in which the nuclear strong force is stronger than it is here. Based on our theories of quantum mechanics and gravity, we can predict how that would affect, for example, star formation. Isaac Asimov explores this idea in "The Gods Themselves."
But Asimov also predicts what alien life would be like in that universe, and there he's on much shakier ground, because nothing in our theories of quantum mechanics or gravity predicts life. We don't know how chemical systems become alive...there's even not solid agreement on the definitions.