Is the cycle of Mutation(changes) in Viruses result of evolution or natural response to exterior stimulus?

Answer 1

Puppy comes the closest, thumbs up.

This is a far more complex question than it appears on the surface. It's true that viruses have a significantly higher mutation rate than other organisms, the question then becomes is this a result of evolution or did this happen by chance? And if this has evolved as a survival strategy for viruses, does the virus actually alter it's replication fidelity (accuracy) in response to host cell stimuli?

It's pretty hard to imagine a mechanism by which viruses would evolve a means to turn on and turn off the mutation process, it starts to smack of directed mutations, which absolutely does not happen. Yet there is evidence that the same virus generates more mutations in different host backgrounds (the work of Marilyn Roossinck and Justin Pita). This would suggest that exterior environment does play some role.

The first question is still debated. The theoretical advantage to generating lots of mutations is that the virus would have a reservoir of genetic variability to draw on in the face of new selection pressures. However, it can be countered that most mutations are neutral or negative in effect, and the few positive effect mutations can be lost in large populations.

Bottom line, we're still trying to figure it out. I've probably gone way overboard, but the subject is near and dear to my heart.

Answer 2

Mutation in viruses is a result of there ability or inability to infect a host. Viruses are not a form of cellular (cyotic) life, they are parasites and must infect a host cell (human, animal, Plant) to continue to flourish and have the resources they need. A viruses whole existence is based on its ability to infect a host cell. So, viruses strains that are ineffective die off and others that are very successful at infecting host cells flourish with this host and sometimes they mutate and jump to other hosts - an example avian flu jumped form birds, to mosquitoes to other animals and humans

Answer 3

This is what's called the argument from incredulity, and it's a fallacy. Your own limited imagination is not proof of anything except that your imagination is limited. "Information is a mental, non-material concept .....It can never arise from a natural process" -- unsupported assertion. "Numerous efforts to bring life from non-life (including the famous Miller-Urey experiment) have not succeeded" -- difficult and impossible are not the same thing. Creating life from non-living matter is difficult (though it could be said to happen all the time inside living organisms; what else is cell regeneration?). Building a working copy-prevention scheme is impossible. "nothing works until everything works" -- wrong, wrong, wrong. "Doesn’t matching male and female reproductive machinery need to exist at the same time, fully-functioning if any reproduction is to take place?" -- no. See "asexual reproduction".

Answer 4

well......HIV for example makes a mistake in copying its genome each time it devides even if the immune system is in a totally bad shape. So....in case of viruses it is simply evolution....it is bound to mutate....even if there is no selection pressure, the HIV would make a mistake. But donot forget that this natural defence against our immune system must have arisen due to a mutation which must've required some kind of selection pressure(or in your words, stimulus). Whereas, if we consider a bacteria, it will not mutate on its own.....it is not bound to make a mistake in copying its genome...it would only mutate if a selection pressure for example antibiotics are used..

Answer 5

Mutation of viruses is due to their rather inconsistent ability to copy their DNA/RNA without error AND possible external factors such as radiation.

Genetic data isn't intentionally changed. This fact is consistant in all lifeforms. In fact the reverse is prefered - all life works at preserving it's genetic data and would not evolve deliberately.

Answer 6

Same thing. Evolution is just change in a population in response to environment.

If, by "response to exterior stimulus" you mean in each individual virus ... viruses don't respond to external stimulus.

Answer 7

both.
evolution is the end result of the natural changes.
or to put it another way, evolution is not a "force" that drives change, it is a description of how changes have happened and their overall effect on species.