A classic example of selection in natural populations involves the peppered moth Biston betularia in England. Industrial gases k
illed the lichens and mosses on buildings, trees, etc., and soot deposited on the landscape. Dark-colored moths gained a selective advantage. In this case, one would say that there was selection against the light-colored moths. Which morph, light or dark, would have the highest fitness? (Enter light or dark in the box below.)
Moths either dark or light live on the bark of the trees. During industrial revolution in England, excessive pollution caused the darkening of bark of trees. Due to this environmental change, some of the light colored moths evolved and turned into dark colored moths. Both bark and moth being dark in color, made the moths untraceable by their predators. While the light colored moths on dark trees were easily recognizable by their predators.
Hence, the dark colored moths possess high fitness.
Ocean currents act much like a conveyer belt. they transport warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. this, currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth's surface.
