Describe the phenomenon of moths observed in industrial areas of England that supports evolution by natural selection.

(N/A) An interesting observation supporting evolution by natural selection comes from England. In the $1850s$,i.e.,before industrialization,it was observed that there were more white-winged moths on trees than dark-winged or melanized moths. However,in the same area,but after industrialization,i.e.,in $1920$,there were more dark-winged moths in the same area,i.e.,the proportion was reversed.
This observation suggested that 'predators will spot a moth against a contrasting background'. During the post-industrialization period,the tree trunks became dark due to industrial smoke and soot. Under this condition,the white-winged moths could not survive due to predators,but the dark-winged or melanized moths survived.
Before industrialization,thick growth of almost white-colored lichens covered the trees - in that background,the white-winged moths survived but the dark-colored moths were picked out by predators. Lichens do not grow in polluted areas. Thus,moths that were able to camouflage themselves survived (Figure). This understanding is supported by the fact that in areas where industrialization did not occur,e.g.,in rural areas,the count of melanic moths was low. This shows that in a mixed population,those that can better adapt,survive and increase in population size.