An entity comes to me in my dream and says I now possess the power to exterminate any biological entity of my choice on Earth at the snap of a finger. Without giving too much thought, I decide to exterminate all viruses.

Can life on Earth continue to exist normally? (Specifically human life) If not, how will it interfere?

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    $\begingroup$ Not an answer, but it's hard to define a virus as a "biological entity". They're not strictly speaking alive, so cannot be meaningfully killed. $\endgroup$
    – jdunlop
    Commented Jul 14, 2022 at 0:29
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    $\begingroup$ As stated in our help center, questions along the line of " what if X happened?" are not a good fit for us. $\endgroup$
    – L.Dutch
    Commented Jul 14, 2022 at 6:15
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    $\begingroup$ To expand on L.Dutch's comments "what are the consequences" are not a good question, but something more directed like, "Can life on Earth can continue to exist normally" is much more pointed, probably what you actually mean, and would be fine. $\endgroup$
    – Nosajimiki
    Commented Jul 14, 2022 at 14:23
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    $\begingroup$ With estimations of the number of different viruses existing floating between 300,000 and 100,000,000 ... this is not the number of biological entities you'd be taking out of existence, it's the number of species ... Talk about a genocide! (But seriously, jdunlop below has the right answer, if all these species die, we all die shortly after). $\endgroup$
    – Hoki
    Commented Jul 14, 2022 at 15:39
  • $\begingroup$ If you want to insta-genocide some species, mosquitoes would be a much better choice. Like viruses, they're well-understood to cause some very serious problems, but many biologists have claimed that they provide no real benefit to ecosystems they're a part of; they could disappear and no creatures would miss them when they're gone. $\endgroup$ Commented Jul 14, 2022 at 22:10

3 Answers 3


Probably Everyone (and Most Animals) Die

There's actually an article on exactly this.

What we do know is that phages, or the viruses that infect bacteria, are extremely important. Their name comes from the Greek phagein, meaning “to devour” – and devour they do. “They are the major predators of the bacterial world,” Goldberg says. “We would be in deep trouble without them.”

Phages are the primary regulator of bacterial populations in the ocean, and likely in every other ecosystem on the planet as well. If viruses suddenly disappeared, some bacterial populations would likely explode; others might be outcompeted and stop growing completely.

This would be especially problematic in the ocean, where more than 90% of all living material, by weight, is microbial. Those microbes produce about half the oxygen on the planet – a process enabled by viruses.

So we might all asphyxiate. We might die from bacterial superinfection, given the sudden lack of phages in our internal microbial ecosystems. Other vital parts of the ecosystem might die and it would be a tossup between asphyxiation and when that broken link in the chain of life reached us.

Very Bad Things, regardless of which end actually reached us first.

Edit: In terms of dividing between "immediate" and "long term" - if it turns out that the billions of bacteriophages in our body really are keeping bacteria (healthy or otherwise) at bay, pretty much everyone immediately and messily dies, on the order of weeks.

If that's not the case, but we have enormous bacterial outgrowth in the oceans, then the world gradually runs out of oxygen. This would be a months-to-years-long process.

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    $\begingroup$ A sharp increase in bacteria would also provide a feast for other bacteria-eating micro organisms. They might increase in numbers to. I wonder what havoc would be caused by certain protozoa exponentially increasing in numbers because their food source increases? $\endgroup$ Commented Jul 14, 2022 at 2:01
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    $\begingroup$ And most complex land plants too. Even plants have a microbiome in the soil around the roots. Roots pump sugars in the soil which will be food for bacteria which in turn convert these sugars in coumpound which the plant can absorb back and use to grow (very much like our digestive system). In this microbiome too, viruses play a regulating role. $\endgroup$
    – Hoki
    Commented Jul 14, 2022 at 15:45
  • $\begingroup$ Or we might all die of ulcers or infection as the natural gut flora in every species becomes unregulated. Ruminants would die of starvation almost instantly, bringing the civilized world down with it shortly after. To quote the great Arthur Dent: "McDonald's, he thought. There is no longer any such thing as a McDonald's hamburger. He passed out." THHGTTG $\endgroup$
    – Vogon Poet
    Commented Jul 18, 2022 at 17:34

Hardly Anyone Notices

The issue with viruses is that they are constantly produced in infected cells, attach to other cells and infect them to make them produce more of the same virus. Your wish is instantaneous, and only kills (decomposes, more likely) all existing copies of all viruses, yet no genetic code gets altered, thus whatever cells are still infected, that is, have virus genome embedded into theirs, would just make more of that virus effectively recreating the majority of virus ... constructions. Some viruses might effectively get extinct, if they only exist in forms like a cyst, or sleep for some eternity within existing cysts, that have virus genome within but do not produce any viruses because of anabiosis, but anything active will just get reproduced.

  • $\begingroup$ And if it kills viral DNA embedded in other organisms, humanity is done for. - - - - Eight percent of our DNA consists of remnants of ancient viruses, and another 40 percent is made up of repetitive strings of genetic letters that is also thought to have a viral origin.”Jan 9, 2020 $\endgroup$ Commented Jul 14, 2022 at 18:12
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    $\begingroup$ Most viruses do not inject DNA into their host cells, by my understanding. It's only retroviruses. $\endgroup$
    – wizzwizz4
    Commented Jul 14, 2022 at 19:22
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    $\begingroup$ I don't think that would count as an extermination. Your theory makes sense if the power was to "kill" any biological entity, but it's not. You can't really say chickens are extinct if you have a room full of eggs that are on the verge of hatching. $\endgroup$
    – Shadow
    Commented Jul 15, 2022 at 4:48
  • $\begingroup$ @wizzwizz4 okay these survive for sure. Those that don't - how do they replicate in host cells? IIRC they make the cells work on their RNA, separated from the injecting virus and released into host cell's cytoplasm along any other RNA the cell itself generates. Again, RNAs are not viruses, and they don't get disassembled upon this wish, so new viruses would still be created. $\endgroup$
    – Vesper
    Commented Jul 15, 2022 at 7:04
  • $\begingroup$ @Shadow chicken in egg is an alive chicken, so it would be affected by a wish of "kill all chicken". Virus in cell is quite a different thing, it's a piece of DNA/RNA, sometimes integrated into host cell's genome, sometimes even adapted by host for its own purposes. Virus outside cell is a virus that can be affected by such a wish, inside it's not even alive, it's already disassembled. Hum. $\endgroup$
    – Vesper
    Commented Jul 15, 2022 at 7:07

Here is a sort of a frame challenge.

Your quesiton is inconsistent. You write:

An entity comes to me in my dream and says I now possess the power to exterminate any biological entity of my choice on Earth at the snap of a finger.

The entity that comes in your sleep is a single supernatural being. So it should be offering the power to kill any single organism. But your word "exterminate" means to kill all the members of a group. So the offer might possibly be interpreted as an offer to kill all members of a single species of organism.

You follow with:

Without giving too much thought, I decide to exterminate all viruses.

For one thing, it is a matter of debate whether viruses are lifeforms and covered by the offer. For another, "all viruses" are not a single individual virus, nor even a single species of viruses, but every genus, family, order, family, class, etc. of viruses, an entire kingdom of life. It is very hard to imagine that the word "entity" could be stretched to cover an entire kingdom of life.

So possibly you might want to have your character's initial request denied by the supernatural entity because it was ungrammaical and ilogical, and have them argue about whether exterminating all viruses fits the initial offer, before the character convinces the entity it does.

So if, as some answers suggest, the wish has very little effect on one hand, or causes everyone to die on the other hand, the readers will more easily accept that the character hasn't thought about his wish enough, if the entity has criticized it for being ungrammatical and illogical and scientifically illiterate.

Possibly the entity was some sort of supernatural or scientifically advanced being sent to destroy the human race, and for its amusement chose to do so by giving half awake humans, not thinking clearly, one wish each, expecting that sooner or later one would make a not carely thought out wish that would destroy all humans.

  • $\begingroup$ And so the answer to the question as currently written would be "no, people continue their lives normally" because nothing was done? $\endgroup$ Commented Jul 18, 2022 at 10:22
  • $\begingroup$ Actually because the contract is ambiguous the answer is either nothing at all or global sterilization within a year. Or, every answer is correct? $\endgroup$
    – Vogon Poet
    Commented Jul 18, 2022 at 17:43

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