Is genetic variation the raw material for evolution?

Why is genetic variation necessary to the process of natural selection and therefore evolution?

• Why is genetic variation necessary to the process of natural selection and therefore evolution?

• Answer:

  To have the possibility to improve! This way some living creatures might adapt themselves better in a determined environment and some others might not.. Thanks to variation living creatures are in some ways more likely to overcome changes in the conditions of living (e.g. new bacteria, new viruses, or changes in the weather etc) all things which might not be compatible with lives of some organisms, but some other ones, which are different thanks to genetic variation, might be more resistant.. this way these will survive and transmit their traits to their children.. Then the children themselves, when they will reproduce, they might have some variations which may bring an improvement, or may bring a worsening of conditions.. In the second case, the new organisms, who aren't made for that environment any more, they will die and just the ones with the "better" mutations will survive.. The ones which have adapted better to external conditions.. If there were no variations, it wouldn't be possible for species to improve, and to grant that in some way their species will survive.. Now that said, many mutations result in a worsening of conditions and these will very likely die and stop the transmission of that mutation.. Wikipedia: Evolution is any change across successive generations in the heritable characteristics of biological populations. And for changes to happen you need genetic variation