The peppered moth has a light and dark colour morph; the light morph was common in pre- industrial England. Increased pollution during the Industrial Revolution allowed dark morph moths to camouflage effectively against the dark, sooty background. Consequently, the dark morph became more common in industrial areas while the light morph remained common elsewhere. Recently, dark morph moths have been decreasing with reductions in pollution. Should the two morphs be considered separate species?
A) No, because they are not in allopatry.
B) Yes, because the dark and light morphs have higher fitness in different habitats.
C) Yes, because natural selection has acted on the frequency of the two forms.
D) Yes, because they have very different phenotypes.
E) No, because there is no evidence that they are reproductively isolated.

Question

Quizplus · Accepted Answer

The peppered moth light and dark morphs should not be considered separate species because there is no evidence that they are reproductively isolated. The two morphs are capable of interbreeding and producing viable offspring, indicating that they are the same species despite having different morphologies. The change in frequency of the two forms is the result of natural selection acting on traits that confer improved camouflaging abilities in different environments, rather than reflecting divergence into separate species.

The Peppered Moth Has a Light and Dark Colour Morph;