# Do viruses serve any useful purpose? **URL:** \ **Category:** Factual Questions\ **Created:** [July 1, 2020, 11:23pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001 "2020-07-01T23:23:24Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [July 1, 2020, 11:23pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/1 "2020-07-01T23:23:24Z")
Just to be clear, I mean the biological type, not the computer type. I’m all for conservation. Any kind of living species should be preserved if at all possible. But it’s dubious if viruses count as living anyway. Anyway, suppose there was some anti-viral medicine discovered that could wipe out all viruses completely. Every virus becomes as dead as smallpox. Maybe, if you like, preserve a sample of each species in a virus zoo. Is there any downside? Are there any beneficial viruses, the way there are beneficial bacteria? I don’t know, maybe there are some that destroy germs that would be harmful to other life forms. Are viruses part of the food chain? Would any species be affected at all adversely if viruses went extinct? ---
**Author:** ![madsircool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/madsircool/32/3432_2.png) [@madsircool](https://boards.straightdope.com/u/madsircool)\ **Post date:** [July 1, 2020, 11:27pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/2 "2020-07-01T23:27:11Z")
There are some good virus in our body. > **[Not All Viruses Are Bad For You. Here Are Some That Can Have a Protective Effect](https://www.sciencealert.com/not-all-viruses-are-bad-for-you-here-are-some-that-can-have-a-protective-effect)** > > Viruses are mostly known for their aggressive and infectious nature. > [@](#): > > But they’re not all bad. Some viruses can actually kill bacteria, while others can fight against more dangerous viruses. So like protective bacteria (probiotics), we have several protective viruses in our body. > > Bacteriophages (or “phages”) are viruses that infect and destroy specific bacteria. They’re found in the mucus membrane lining in the digestive, respiratory and reproductive tracts. > > Mucus is a thick, jelly-like material that provides a physical barrier against invading bacteria and protects the underlying cells from being infected. Recent [research suggests](https://www.pnas.org/content/110/26/10771) the phages present in the mucus are part of our natural immune system, protecting the human body from invading bacteria. ---
**Author:** ![racer72](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/racer72/32/3075_2.png) [@racer72](https://boards.straightdope.com/u/racer72)\ **Post date:** [July 1, 2020, 11:29pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/3 "2020-07-01T23:29:35Z")
A guy I work with calls it population control. ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [July 2, 2020, 12:47am UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/4 "2020-07-02T00:47:51Z")
Suttle (2005): “Viruses exist wherever life is found. They are a major cause of mortality, a driver of global geochemical cycles and a reservoir of the greatest genetic diversity on Earth. In the oceans, viruses probably infect all living things, from bacteria to whales. They affect the form of available nutrients and the termination of algal blooms. Viruses can move between marine and terrestrial reservoirs, raising the spectre of emerging pathogens. Our understanding of the effect of viruses on global systems and processes continues to unfold, overthrowing the idea that viruses and virus-mediated processes are sidebars to global processes.” [https://www.nature.com/articles/nature04160](https://www.nature.com/articles/nature04160) So with regards to your plan, I’m going to have to see your environmental impact statement. 🙂 ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 2, 2020, 1:35am UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/5 "2020-07-02T01:35:47Z")
Maybe we could [pile them all together](https://what-if.xkcd.com/80/). I’m not sure exactly what changes would happen if all viruses were removed, but they would be hugely profound. ---
**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\ **Post date:** [July 2, 2020, 1:48am UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/6 "2020-07-02T01:48:24Z")
Would getting rid of viruses include the roughly [8% of our genome that is virus dna](https://www.nytimes.com/2017/10/04/science/ancient-viruses-dna-genome.html#:~:text=Hemo%20is%20not%20the%20only,DNA%20is%20doing%20to%20us.)? ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [July 2, 2020, 1:51am UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/7 "2020-07-02T01:51:18Z")
yes, they’re a form of population control. they serve the purposes of Earth, not human beings. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [July 2, 2020, 12:06pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/8 "2020-07-02T12:06:58Z")
No life form serves the purposes of anything. They exist because they can reproduce. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 2, 2020, 1:46pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/9 "2020-07-02T13:46:28Z")
The purpose of viruses is to make more viruses. Now, you might not think that’s a very good purpose, but the viruses disagree. Not everything needs to have a purpose to us. But that doesn’t answer the OP’s question. If we could eradicate all viruses completely, should we? And the answer to that is that it’s impossible to know what all the consequences would be. Ecosystems are the most complicated systems humans have ever encountered, and any direct effect in them will have indirect effects. Eradicating all viruses would be a huge change, and we simply can’t know what all of the indirect effects would be. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [July 2, 2020, 7:18pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/10 "2020-07-02T19:18:15Z")
Bacteriophages (aka phages) were mentioned above. They “eat” bacteria, although what they actually do is destroy them in the same way other viruses destroy our cells: turn them into virus reproduction factories. There has been considerable work in Russia and now some of it is being carried out in the US to study the possibility of using phages to fight bacterial infections since we seem to have run out of antibiotics. A major advantage of this is that phage can mutate just like bacteria can. About 65 years ago I took part in an informal experiment. In fact it was just a grad student in a bio lab and and an undergrad technician (me). We prepared an aerated flask filled with a nutrient medium and injected some E. coli into it. A day later the flask had changed from a clear medium to cloudy as it filled with bacteria. We then added a sample phage (one of the T phages but I don’t recall which one) and a day later the flask had cleared up and the bottom was filled with dead bacterial cells. But the next day, it had clouded up again as mutant bacteria grew to fill the flask. But the day after that, it cleared up again as mutant phage took over. Since this was an informal (that is unauthorized) experiment, we stopped there. The original flask was too full of dead bacteria and waste products to continue. Think of it as evolution in action. But I wouldn’t be in any hurry to rid the world of viruses. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [July 3, 2020, 3:51pm UTC](https://boards.straightdope.com/t/do-viruses-serve-any-useful-purpose/914001/11 "2020-07-03T15:51:49Z")
Some gene therapy is delivered by viruses. Humans have taken advantage of their ability to infect and replicate to “infect” people with good copies of genes they need. Not all gene therapy works this way, and it would be wrong to say that viruses exist for this purpose. Wheat doesn’t exist for us to make bread-- it’s just something we figured out how to do with an existing thing that existed for its own sake. Mud doesn’t exist for us to make bricks or clay vessels, either, but we figured out how to take advantage of it, too. And so we figured out how to take advantage of viruses. We can wipe out the most dangerous ones to us, but the ones that we can make use of, or that have exploited a niche by becoming beneficial to us, we’d better keep.