[Alan McDougall (OP)]

Greetings,

Please ignore my ignorance, from my perspective I do not know of any friendly viruses that help like digestive stomach bacteria does.

What purpose does the huge diversity of viruses have in the grand order of nature?

Alan

[Bored chemist]

Who says they have to have a purpose?

For what it's worth there are a few that we make use of. Some viruses atack bacteria and these are sometimes used to treat people who wre infected by those bacteria.
http://en.wikipedia.org/wiki/Bacteriophages

Also we use some viruses like vaccinia (cowpox) to provoke an immune response to similar but more dangerous viruses like smallpox. Since there's no smallpox about any more you could say the vaccinia was useful.

http://en.wikipedia.org/wiki/Vaccinia

[SquarishTriangle]

Possibly because we tend to be a little self-centric and study viruses from the perspective of the diseases they cause and how we can get rid of them.

If you consider that certain viruses are able to insert their own genetic information into the host genome and have it consequently expressed in the cell with adverse effects (eg. the insertion of a viral oncogene leading to neoplastic transformation), then it would be conceivable that, by random chance, the insertion of beneficial genes could also be possible. By a similar sort of principle, adenoviruses are used vectors in gene therapy as a means of inserting a specific normal copy of an absent or defective gene into a patient, thereby allowing expression of the normal gene to occur.

[chris]

Hi Alan

Bored chemist raises a good point, which is that bacteriophages, which are bacteria-specific viruses, are very useful as antibiotics: http://www.thenakedscientists.com/HTML/articles/article/virusesvssuperbugs/

...and as microbes become progressively more resistant to existing antimicrobial drugs, they are looking more and more attractive as an option.

It's also worth bearing in mind that viruses acts as biological ferries that can carry genes between different organisms and even different species. They can, therefore, contribute to genetic diversity. For instance there is a sacoglossan sea slug that contains plant genes capable of keeping chloroplasts (photosynthetic organs) alive in the slug's body. These slugs eat algae (marine plants) and move the chloroplasts from the algae to their skin where they are used to capture energy from the Sun for the slug.

Scientists suspect that, at some point, a virus was responsible for accidentally adding the correct genes from plants to the slug's DNA, enabling this clever trick to take place.

So viruses, whilst making us ill on and off, also contribute to evolution and diversity and therefore make the world a genetically better place!

Chris

[Alan McDougall (OP)]

Hi Chris,

So viruses, whilst making us ill on and off, also contribute to evolution and diversity and therefore make the world a genetically better place!

Chris I find that viruses might be partly of completely responsible for evolution a fascinating thought. As you know there are still unexplainable aspects to the standard evolutionary theory of advantageous mutation,natural selection and survival of the fittest. Viruses might cause these mutations to somehow sustain their own existence

The ate nasty critters at the best of ties are they not

You really might be onto something here what an original thought.

Regards

Alan

[blakestyger]

There is no purpose to nature so teleological explanations for why things have evolved the way they have are invalid - as purpose implies a design/designer. The reason that there is such a huge diversity of viruses is that they are able to mutate very quickly in response to changes in their environment - plus all the reasons chris has given.

[@@]

hello all nasal nasty ingurgitators, it is i "jay" who emailed this question, i call myself @@ on most forums, anyhoo thanks for the great response, i believe the question will be on one of the shows, im looking forward to that
 the idea of bolstering the imune system did cross my mind but the post by "make it lady" was something i hadnt thought of.
 

[blakestyger]

You've stuck this in the wrong place. []

[Alan McDougall (OP)]

@@

hello all nasal nasty ingurgitators, it is i "jay" who emailed this question, i call myself @@ on most forums, anyhoo thanks for the great response, i believe the question will be on one of the shows, im looking forward to that
 the idea of bolstering the imune system did cross my mind but the post by "make it lady" was something i hadnt thought of[/quote[/color]]

What the heck are you writing about []

[NHF7]

I may be somewhat late, and possibly alone in making a comment to this thread. Nevertheless, I have often muted the question of the virus and its purpose in Mother Nature’s Grand Plan. Yes, I have considered their (assumed) role in evolution, but in the end I have come to one either very simple, or deeply philosophical conclusion: Mankind is a Virus. QED.

[evan_au]

What positive purpose does a virus have in nature?

Mankind is a Virus.

So a virus is a natural metaphor... 

[alancalverd]

Wrong end of the microscope.

God's purpose for plants and animals is to provide an environment for viruses and bacteria to go about their business.

[evan_au]

One function of viruses is to prevent one species from taking over an entire ecosystem.

When an ecosystem contains many species in balance, virus outbreaks will be sporadic and will die out by themselves. Once one species becomes dominant, it is possible for one virus to persist in the ecosystem, and limit the extent of species dominance.
- This plays out in our microbiome, where many kinds of microbes play a complex dance, with archaea, bacteria, fungi & viruses forming the ecosystem.
- It is also applicable to humans, who have greatly reduced species diversity in many parts of the world.
- Unlike natural ecosystems, where predator and prey adapt over many generations, humans can now adapt to a new pathogen in a small fraction of the human lifetime (eg with vaccines).

[alancalverd]

I have to disagree.

The red squirrel has almost disappeared from the British Isles, displaced by the immigrant grey squirrel which occupies pretty much the same ecological niche but tolerates the parapoxvirus, so has become the dominant species.

And the problem with COVID19 is that it mostly kills humans past reproductive age, so it won't have much effect on human dominance in the medium term.

[edulofter]

The existence of abundant viruses must be reasonable.
The entire biological system is extremely complicated. I personally believe that a virus must exist for another organism. In the evolution of nature, they need to coexist and restrict each other.