Jerry Richard Boone our expert of the day, writes:

Mutations create variety in a population, and Natural Selection culls out the unfavorable results. But does this process lead to macro evolution? or micro evolution? Let’s check it out.

British peppered moth

Species can and do change over time. At least some of them do. One historical example is the British peppered moth. This variety of moth has made its home in Manchester, England for, well, as far back as anyone can remember. They sport a distinctive light speckled grey coloration on their wings. They perch on trees much the same color as themselves, thereby blending in nicely with their background.

Back in the 1840’s, Manchester was developing into a major center of British industry. Factories blackened the local vegetation with soot and other pollutants. Against the dark soot covered trees, the lightly covered pepper moths stood out like beacons for bird predators. As you can well imagine, the moth population plummeted. That, however, is not the end of the story.

By 1848, darker colored peppered moths began showing up. By the middle of the century, the darker variety had almost completely replaced the lighter pigmented forms in the polluted areas. In unpolluted areas, lighter colored pepper moths remained common. What do you make of it?