How important are mutations in natural selection?

Question

How important are mutations in natural selection?

Answer 1

I believe it is very important. Of course, I cannot say that I like it when God or Nature throws out a mutant bacteria or virus that will not bend to our normal medications.......such as HIV, or AIDS, or MRSA.

I believe it is important, in order to 'finish with the best it can be', for the creator to throw out different things to see how they work in our environment.......if the flourish, they stay, if they cannot manage, they are eliminated.

Answer 2

1st limitation:  Most mutations are biologically meaningless and have no appreciable effect on evolution.  

2nd limitation:  For a mutation to be passed on to offspring, it must be attached to a s*x cell.  This does not happen all that often, and is only possible when the mutation occurs in the female of the mating pair.

3rd limitation:  Mutations are more or less random genetic drift (except for mutations caused by mutagenic substances), so environments do not, generally, cause them or even affect their timing and how they play out.

Once a mutation occurs in a s*x cell, the constraints discussed by Jerihuana above can take hold.  The only difference between his opinion regarding the subsequent behavior of natural selection and my own vis a vis mutations is that I would argue that selective pressure does not really favor beneficial mutations, but rather simply filters out that which does not fit in the ecological niche occupied by the organism. In other words - it's not necessarily survival of the fittest, but survival of the adequate.  

In summary, most mutations end up having no net effect on evolution.  Under very specific circumstances, mutations may be passed on to offspring (whether or not they are beneficial). Most mutations  which are passed on will not effect the organism's fitness. Once a mutation has a stable breeding population associated with it:  

*  if the mutation is beneficial it may give that population a competitive advantage

*  if it is irrelevant it may continue to be passed on

*  if it reduces the organism's fitness in its ecosystem, the organism may either move to a niche where the mutation is less of a problem or may become extinct.  

There is more to all of this, but these are the basics.  Note also that some people will disagree with my argument against "survival of the fittest" (which I view as a myth of progress).  That's fine, but I strongly recommend reading Darwin and Stephen J Gould for a start before developing strong opinions on this subject.

Answer 3

It all depends on whether or not the mutation is beneficial to an organism.  If a mutation helps an organism to do better in its environment (live longer, reproduce more) then over time that mutation will become more predominant in a population as it helps the organisms with it survive better than the ones without.

if the mutation is detrimental to an organisms survival, they won't be around long enough to pass it on in their genes.

Answer 4

Mutation is essential for natural selection it is the foundation of the theory of evolution. Without mutation there is no evolution, no change.