Good Bacteria-Bad Bacteria

[pdq1]

For instance we all depend on good bacteria to break down our food in the gut. But elswehere we have other bacteria that can cause serious illnesses. Did they both originate from the same bacteria via mutation? Also can that also be said for the viruses that cause such horrible illnesses. In other words did the good organisms always precede what happened later.

[rojash]

What a strange question. Bacteria evolved to survive, if a side-effect of their survival is the breaking down of food in the gut, that doesn't make them good or bad, it just means that they happen to be useful to us. Why would you assume that all bacteria originally existed in a form that was beneficial to humans?

Also, from our point of view, many bacteria are like plants - in the right place they are good for us and in the wrong place they are not.

[jim360]

Exactly rojash. While the origins are partly the same, bacteria definitely did not choose to be good or bad. They only did what they needed to survive. Indeed bacteria were here far earlier than we were, so if anything we are a problem for them!

[Canary42]

No doubt God created the Good bacteria and Satan created the Bad bacteria :-)

(Eat your heart out goodlife)

[LazyGun]

Its a rather odd way of referring to bacteria as being good or bad - its a bit anthropocentric.

Rather, bacteria have thoroughly colonised humans, and have adapted along with humanity to form a relationship that is not just commensal, but beneficial, aiding in all sorts of ways, from aiding the immune system through to aiding in the digestion of foods.

What is termed bad bacteria is often an organism strange to our own system, which can have some unpredictable effects.

So

[jake-the-peg]

Viruses are particularly interesting because they aren't really alive outside of a host - just a really complex chemical.

They evolve with their target host over billions of years, change and counter change, some will have been unable to evolve and will have died out, others may have wiped out their host species and have consequently died out too.

[Old_Geezer]

Good or bad in relation to what they do for us, rather than intent. So the catagorisation of good and bad doesn't really have meaning until a "higher" lifeform is around to be affected by them.

Unless you believe life sprung into existence in numberous places on the planet at once then surely all living things originate for the same first appearance of life ?

As for whether viruses and bacteria originated from the same initial virus and bacteria, I'm guessing probably so but couldn't be sure. We'd need an expert in the field to tell us what the latest popular theories are.

[Old_Geezer]

Actually that reminds me of something I was wondering about. Flatulence. Is that caused by the animal that expels the gas, or by the bacteria inside them acting on the food ? Or maybe a bit of both ?

[LazyGun]

Its a mixture of causes, O_G. NHS Choices has a very good page on it, but the bacteria can in part contribute to flatulence as they break down unabsorbable carbohydrates.

http://www.nhs.uk/Conditions/Flatulence/Pages/Causes.aspx

[Old_Geezer]

Ah, so I can't claim it wasn't me then.

[mibn2cweus]

One can claim whatever they like . . . but barking spiders tell no lies.

[qatarmaggs]

Not an answer you your question but on the subject of bad bacteria. My husband has Parkinson's Disease. It is thought by the neurologists to be purely a brain issue. However, he is on a research programme that looks at the damage to the brain being the result and what goes on in the gut as possibly being the cause. Many people with Parkinson's are found to have helicobacter pylori or rarer animal versions of helicobacter and it is thought that they could have had these since childhood paving the way for a breakdown in proteins that in turn are responsible for brain cell death associated with Parkinson's. Personally I strongly believe in we are what we eat and if we weaken our bodies filling them with food additives etc then we must expect to be vulnerable to hosting bad bacteria. Beware the damage sometimes may by irreversible.

[LankyLanky]

The short answer is yes. Almost certainly there was one prototype bacterium, a long, long time ago.

In evolutionary terms there can be a selective advantage for one species that inhabits another (the host) and also benefits its host. This is known as symbiosis. However there can be a disadvantage if the host species turns out to be poorly adapted in other respects. Like the parasite jumped on the wrong bus. But many parasites have more than one possible host species.

A parasite that kills its host may still be viable due to its very short reproduction cycle and ability to disperse. However, if it wipes out its host 100% it will contribute to its own decline unless it can cross to another species.

Parasites such as the cold virus have no disadvantage as they do not ordinarily kill their host.