Question

In a species of snail, dark-shelled individuals are better hidden from bird predators in the shady forest, while light-shelled individuals 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?

Answer 1

The correct answer is: Disruptive Selection.

Explanation:

• In evolution, the concept of Disruptive or Diverging selection can be defined as the phenomenon due to which, in a population of a particular species, among the different variants available for a particular trait, the most contrasting ones get selected by natural selection and exist in the population while the intermediate traits get eliminated.
• In the given question, a species of snail with the shell color trait is analysed.
• In the snail population, two variants of snail shell color, dark shell and light shell are predominant.
• Natural selection has selected the dark shell color to protect the snails from bird predators in shady forests.
• Natural selection has selected the light shell color to protect the snails in well-lit bushy regions.
• These two variants of snail shell color are contrasting to each other and have resulted from Disruptive Selection.