Answer :
Final answer:
During England's Industrial Revolution, the darkening of moths is explained by natural selection due to environmental changes. As soot darkened tree trunks, dark-colored moths were less visible to predators than their light-colored counterparts, leading to a survival advantage and an increase in their frequency in the population, exemplifying directional selection.
Explanation:
During England's Industrial Revolution, the theory of natural selection explains the darkening of moths as a result of environmental changes caused by pollution. Initially, most moths were lighter-colored and easily camouflaged against the light-colored trees, protecting them from predators. However, as industrial activities increased, soot and pollutants darkened the tree trunks, making light-colored moths more visible and therefore more vulnerable to predation. In contrast, dark moths, which were once at a disadvantage, now found their coloring to be a beneficial adaptation. They could blend in better with the soot-covered trees, reducing their likelihood of being eaten by birds. This shift in the environment led to a situation where the dark moths had a higher survivability and reproductive success. Over time, natural selection favored the darker-colored moths, leading to an increase in their frequency within the population, a phenomenon known as directional selection. The initial hypothesis by J.W. Tutt in 1896 regarding the selective predation by birds upon more visible moths further underscores this natural selection process. By 1895, dark-colored moths significantly outnumbered their lighter counterparts, a dramatic change that underlines the impact of selective pressures on species adaptation.
