(a)[3]
Explain what stabilising selection means.
(b)
Fig. 8.1 displays the distribution of fur colour in a mouse population. The soil in the habitat where the mice lived was mid-brown.
(b(i))[2]
Suggest why the numbers of white-furred mice and black-furred mice were lowest in Fig. 8.1.
(b(ii))[2]
An environmental change made the soil turn dark brown. On Fig. 8.1, sketch a curve to show the fur-colour distribution in the mouse population after many generations.
(c)[2]
Explain what genetic drift means.