During an investigation on peppered moths, a student learned that before industrial pollution in England, light-coloured moths were more common. After pollution darkened tree bark, dark-coloured moths became more common. Which factor was responsible for this change?

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Question

During an investigation on peppered moths, a student learned that before industrial pollution in England, light-coloured moths were more common. After pollution darkened tree bark, dark-coloured moths became more common. Which factor was responsible for this change?

Accepted Answer

Predators selectively ate moths that were more visible against the bark — Award 1 mark for identifying differential predation as the selective pressure. Moths that contrasted with bark were more easily seen and eaten by birds. A is incorrect — individual organisms cannot change their genetic colour during their lifetime. C is incorrect — the change occurred within the existing population. D is incorrect — pollution did not directly cause the mutations; variation already existed in the population.

Answer

Dark moths migrated from other countries

Answer

Pollution directly caused mutations that turned moths dark

Answer

Moths changed colour during their lifetime to match the bark

Answer

Predators selectively ate moths that were more visible against the bark

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