Answer:
The changes occurring in the peppered moth population is one of the most important studies which show the Darwin's proposed phenomenon of natural selection.
Before the industrial revolution, very rare black peppered moth existed. There were mostly light-coloured peppered moths. The colour of moths at that time was best to help them escape from predators. They were able to blend in with light coloured lichens and tree barks and escape from their predators.
But with the industrial revolution, the colour of the trees became darker due to the emission of dust and other gases. With the passage of time, it was seen that the peppered moth began changing its colour into a dark type. The black coloured moths were better able to survive now, hence these type of moths reproduced and increased in population. Whereas, the population of the light coloured moths declined. It was also observed that the allele for dark colour was dominant over the light colour. Hence, the change of colour evolved rapidly.