Through predation, for instance. Under particular circumstances, prey that are able to detect - see - predators sooner will have a better chance of getting away, and passing their better sight on to offspring, than prey with poorer eyesight.
I assume you mean natural selection drives evolution.
natural selection
Adaptation is the result of natural selection.
Basically, the ones who have the worst adaptions to survive in the environment it lives in, will die, while the ones with the best adaptions will thrive and breed, gradually making the better adaption dominant in the surviving members of the species. This is how you can have different features (say thicker beaks, longer tails, smaller eyes) in different sub-species of the same species - they've evolved for a different environment, and therefore have different adaptions.
by natural selection.
Environment IS natural selection, so a change in environment is a change in selection pressure.
I assume you mean natural selection drives evolution.
Natural selection seems to be the only selection that can drive speciation with powerful adaptive change. Sexual selection seems to stay within the species and both gene flow and genetic drift do not seem to drive speciation very well.
Its NaTuRaL sElEcTiOn if you didn't know.
natural selection
Adaptation does not allow for natural selection: natural selection causes adaptation.
Genetic variation in itself does not 'support' natural selection: it is what natural selection acts upon.
Natural selection is what causes adaptation.
Natural Selection
Natural selection.
Adaptation is the result of natural selection.
No, natural selection is the mechanism that drivesevolution.