How is the peppered moth an example of natural selection and fitness?

The pepered moth used to have a diffrent color that was black and predaters could easily spot the moth but because of pullution the trees became black and it was harder for predators to see the black moth so white moths became easily spoted by predators and because white moths where not blended in to there enviroment they started to change and they where changing to black moths and so there were barley any peppered moths