Solution:

White-winged moths were seen in greater numbers on trees than dark-winged or melanized moths. However, as a result of industrialisation, there were more dark-winged moths in the same area, reversing the proportion.

The white moths were able to thrive before the Industrial Revolution because the tree bark was covered with white lichens, making them undetectable by predators. Due to industrial smoke and soot, tree trunks grew dark during industrialization, and predators were recognised.