The Peppered Moth Provides a Well-Known Example of Natural Selection

question 65

Multiple Choice

The peppered moth provides a well-known example of natural selection. The light-coloured form of the moth was predominant in England before the Industrial Revolution. In the mid-19th century, a dark-coloured form appeared. The difference is produced by a dominant allele of one gene. By about 1900, approximately 90% of the moths around industrial areas were dark coloured, whereas light-coloured moths were still abundant elsewhere. Apparently, birds could readily find the light moths against the soot-darkened background in industrial areas and, therefore, were eating more light moths. Recently, use of cleaner fuels has greatly reduced soot in the landscape, and the dark-coloured moths have been disappearing. Should the two forms of moths be considered separate species?

• A) Yes; natural selection has affected the frequency of the two different forms.
• B) Yes; they have completely different colouration.
• C) Yes; they are reproductively isolated based on habitat.
• D) No; they still can interbreed.

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Definitions:

DNA

Deoxyribonucleic acid, a molecule containing the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.

Rooting Reflex

An innate reflex in newborns, where they turn their head toward anything that strokes their cheek or mouth, searching for the object by moving their head in steadily decreasing arcs until the object is found.

Cheek

The fleshy part of either side of the face below the eye and between the nose and ear.

Infant

A very young child, typically under one year old, who is in the earliest stage of human development.