Final answer:
Natural selection is the process by which certain traits or characteristics become more or less common in a population over time. An example of natural selection at work is the peppered moth in England.
Step-by-step explanation:
Natural selection is the process by which certain traits or characteristics become more or less common in a population over time, based on their impact on survival and reproduction. It is a fundamental mechanism of evolution. An example of natural selection at work is the peppered moth in England. Before the Industrial Revolution, the majority of peppered moths had light-colored wings, which helped them blend in with the lichen-covered tree trunks. However, as industrialization led to pollution and darkened the tree trunks, the darker variant of the peppered moth became more advantageous as they were better camouflaged, leading to an increase in their population.