[Maximum number: 3]
Variation exists in populations of a species and this may provide the opportunity for evolution to occur.
(a)
(i)
Outline the theory of evolution.
[ 3 ]
[Maximum number: 4]
A subspecies is a genetically distinct population of a species that has some phenotypic differences but is not yet reproductively isolated.
500000 years ago, the European house mouse, Mus musculus, evolved into two subspecies, Mus musculus domesticus and Mus musculus musculus.
(a)
Suggest and explain how the two subspecies M. m. domesticus and M. m. musculus could have evolved from the original M. musculus population.
[ 4 ]
[Maximum number: 3]
A large number of alpine plant species grow in the mountains of New Zealand's South Island. Alpine plants are defined as plants that live above the treeline, which is the height above which trees cannot grow. The current treeline for most of South Island is 1200 m .
(a)
Fig. 5.1 shows two aspects of the history of South Island over the last 3.9 million years.
- The dashed line shows how the mean height of mountains in the Clyde region of South Island increased over time. The mountains in this range have a mean height of 2400 m at the present time.
- The solid line models the height of the treeline over time based on geological climate data. The treeline was higher when the climate was warmer, and the treeline was lower when the climate was colder, during ice ages.
Fig. 5.1
[ 3 ]
(i)
With reference to Fig. 5.1, identify with reasons the time period when South Island's alpine plant species developed.
[ 3 ]
(a)
State the general theory of evolution.
[ 1 ]
[Maximum number: 3]
The Death Valley region of Nevada in the USA used to have an extensive lake system. Approximately 20000 years ago the lakes started to dry up and now consist of isolated small pools. Four different species of the desert pupfish have been found living in these pools. Evidence indicates that over 20000 years ago there was only one species of pupfish living in the lake system.
Fig. 8.1 shows a desert pupfish.
Fig. 8.1
(a)
Suggest what may happen to the desert pupfish if water levels rise and the pools once more form an extensive lake system.
Answer one question.
[ 3 ]
(a)
State the general theory of evolution and explain the process of natural selection in evolution.
[ 7 ]