When I say germs I mean things like bacteria, viruses, parasites, etc. Is it their intention to kill the host? Why? Isn’t this self defeating? Why would any organism cut off its own life support? Nature is not supposed to work that way.
I think it’s because the germs are feeding and propagating. They have no idea they’re killing the host.
Nature ain’t perfect. :rolleyes:
Generally, they don’t. A well-adapted parasite (which is what disease organisms are) has minimal effects on its host. A virulent disease organism is normally one that has jumped from a different organism fairly recently. It is thought that many humans got many of their disease organisms from domestic animals, in which they cause little problem.
Ebola is so deadly precisely because humans are not its normal host. Rhinoviruses (the common cold) are examples of disease organisms that are well adapted to humans. They produce symptoms that help their spread (coughing, sneezing) but very rarely kill.
Not planning for the future hasn’t bothered germs so far.
As for how nature is supposed to work, it seems to be doing fine so far as well.
For many fatal infections it’s not the direct effect of the infecting agent that kills the host. It’s the host’s immune response that does it. In those cases the host is ultimately killed by friendly fire.
This is interesting. Now I’m wondering just what it is that these teeny tiny critters do that kills people. Or not, as the case may be.
It’s getting late, I’m full of cheap wine and thinking too much. I better go to bed now.
The yeast in your wine drowned in its own shit.*
Expecting intelligence in single-celled organisms is insane.
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- it eats sugar and shits ethanol.
In order for humans to survive, we must eat cows. In the process of cutting them up into steaks and grinding them up into hamburger, we kill them. So it goes.
(Vegetarians may substitute “kale” for “cows.”)
They may kill one host, but they spread to others, so overall, it’s a successful strategy.
Not every bacteria kills its host - may hosts depend on bacteria to survive - like your own body Cite
Yum. Kaleburgers.
We need a “yuck face” emoticon on this board.
Isn’t the ideal condition one where the disease germ benefits the host? Like coliform bacteria-they live in our guts, help us break down and absorb foods, and generally enhance the neighborhood. of course, when we eat certain indigestible stuff (like beans), the register a protest.
This is what i have always wondered-if we could genetically modify deadly diseases, so that they would behave like coliform bacteria, then they would displace the harmful versions, and leave us alone.
As noted upthread, in some cases the disease organism inspires an immune response that causes the death of the host. See for example cytokine storm.
In other cases the damage is done directly by the disease organism. Many bacteria release toxins that cause injury/death. Two examples:
E coli 0157:H7 produces shiga-like toxins.
Clostridium botulinum produces botulinum toxin. This stuff has proved useful in small amounts as Botox, but it’s more problematic when it’s produced in large quantities in your gut by an infection. Death tends to happen when the breathing muscles become paralyzed by the toxin.
This. A germ killing you isn’t a feature, it’s a bug.
Yeah, sorry, I’ll let myself out.
Lots of good information here. Thanks for the answers.
In general this is true but there are cases where killing the host, either directly or indirectly, is a part of the life-cycle of the parasite. I thinking of cordycep fungi that infect insects (for example an infected ant will climb up to a high place and clamp down with its mandibles as it dies to help spread the spores) or toxoplasma infection that makes mice be attracted to the smell of cats (toxoplasma reproduces in the guts of cats). Lots more examples especially in invertebrates. I can’t think of any human pathogens that do this but there could be some.
You may as well ask why fisherman overfish. And often resist attempts to rein them in.
The fact that Ebola exists at all suggests the possibility of a virus or bacterium that kills humans like flies and copies itself like wildfire.
However, such an organism would be extincting itself. In addition, evolution usually operates in infinitesimal substeps. An organism that gets closer to mass murdering it’s host may be less successful than variants of the organism that move in other ways.
This is why waterborne diseases are so bad. Diseases that require the host to move to spread them can’t cause the host to be unable to move or be dead because it means that variant of the virus or bacteria failed and will die with the host. Diseases that just require the host’s dead body to contaminate a water source or to vomit into it can be much nastier.
Once in a new host, germs will evolve towards maximum propagation. Whether this drives the germ to greater or lesser virulence depends on the mode of propagation and on the hosts defenses.
One possible direction is towards minimal virulence, keeping the host alive, active, and interacting with many potential new hosts. This would be the case if transmission were though close or direct contact and if the host’s immune response didn’t attack the germ strongly. In other conditions, however, evolution may drive the germ to a full-on-assault strategy: coping itself as fast as possible before the host’s immune response kicks in and before the host dies. If the mode of transmission is, say, though water, the germ may be able to get itself out there and into new hosts even as its host dies. A third strategy would be to keep the host alive but too weak to mount a strong immune response.
I was under the impression that a parasite will even feed upon itself…,
[QUanuthead;18658644]OTE=Pe Is it their intention to kill the host? Why?*
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Isn’t this self defeating? Why would any organism cut off its own life support? Nature is not supposed to work that way.*
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Nature nurture it’s all the same, in due time we as in the human race will no longer eat flesh to survive.
The process just takes time and believe me, He has all the time he wants,.,.,…
as I see it. How about you-?
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