Humans can unintentionally change an organisms environment affecting natural selection, but they can also manipulate change their traits through artificial selection. Unintentional evolutionary changes can be seen in the peppered moth during the Industrial Revolution. The amount of pollution and smog that coated surfaces in cities during this period drastically increased. This pollution caused surfaces to become blackened causing the lightly colored moth to be more exposed to predators. This unintentional human interaction caused natural selection to occur with an allele frequency change to include a larger number of black colored moths. In cases of artificial selection direct human intervention causes the level of fitness in organisms.
