Many alpine plant species are found in the mountains of New Zealand’s South Island. Alpine plants are plants that live above the treeline, meaning the altitude beyond which trees are unable to grow. For most of South Island, the present treeline is $1200\,\text{m}$.
(a)[5]
The alpine regions closest to South Island are $1500$-$2000\,\text{km}$ away across the sea. Many alpine species on South Island are found nowhere else in the world. Explain how a large number of alpine plant species came to exist on South Island.
(b(i))[3]
Using Fig. 5.1, identify the time period when South Island’s alpine plant species evolved, and justify your answer.
(b(ii))[2]
Suggest how DNA sequence data could be used to confirm the time period you identified in (i).
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “natural selection, evolution or speciation” …