Explain how the pepper moth mutation is an example of natural selection.

So the pepper moths adapted to their environment due  to all the coal that was being burned at the time, the coal left soot on almost everything making it all covered in black soot, the moths started to turn darker, due to this the lighter colored moths were eaten by predators, while the darker ones blended in to the soot. the mutation was the moths changing color to match their environment  

Idont really understand

Soil? it sounds right when you r3ad it in a sentence