Final answer:
The change in color of peppered moths during the Industrial Revolution from light to dark due to environmental changes is a classic example of directional selection and can contribute to speciation, as differing survival and reproduction rates can lead to the divergence of a species.
Step-by-step explanation:
The color of moths, particularly the peppered moths in nineteenth-century England, is a well-documented example that helps in the explanation of speciation. Initially, light-colored peppered moths were prevalent due to their ability to camouflage against unsoiled tree barks. However, the Industrial Revolution brought about significant environmental changes, coating trees in soot and making dark-colored moths more difficult for predators to spot. This led to directional selection, where the darker moths had a higher survival rate and were more likely to reproduce, causing a shift in the moth population from predominantly light to dark-colored. Over time, this change in the environment and resulting selection pressures could contribute to the speciation process as moths adapt to their changing habitats.
Speciation occurs when a group within a species diverges and becomes a distinct species, often through mechanisms such as natural selection and genetic drift. In the case of the peppered moth, as darker moths became more common, this could potentially lead to differentiation from the original population if other selective pressures or reproductive barriers enhance the separation. This illustrates how natural selection and environmental factors drive speciation.