In a species of snail, dark-shelled individuals are better hidden from bird predators in the shady forest, while light-shelled i
ndividuals are better hidden in well-lit brushy edge areas. If there were no areas of intermediate brightness in this habitat,which type of selection would act on shell color in these snails?
Disruptive selection is the type of natural selection wherein two extreme phenotypes are favored due to their survival and reproductive success over the intermediate phenotype. It results in two peaks of distribution in the normal distribution curve.
In the given example, two extreme phenotypes with respect to the shell color of snails are favored in two different habitats. Dark shelled snails exhibit survival advantage in the shady forest while the light shelled snails are favored in well-lit habitats.
Since two extreme shell colors are favored over the intermediate-range by natural selection, it represents disruptive selection.
