 Directional selection - Sources: Encyclopedia II - Directional selection - ExampleA common example is the peppered moth (Biston betularia). Before the industrial revolution in England (1740?), the peppered moth was mostly found in a light gray form with little black speckled spots. The allele for dark-bodied moths is dominant, while the allele for light-bodied moths is recessive. The light-bodied moths were able to blend in with the light colored lichens and tree bark. The less common black peppered moth was more likely to be eaten by birds. Therefore, the frequency of the dark allele was about 0.01%. During the industria ...
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