Interpret phenotype distributions to distinguish stabilising, disruptive and directional selection, explaining which variants are favoured and how the population pattern changes in Cambridge A Level Biology questions.
Fig. 7.1
The body mass of red deer shows wide variation within a population. This is shown in Fig. 7.2.
Fig. 7.2
A selection pressure acted consistently over many years against red deer of low body mass in a population.
Sketch a curve on Fig. 7.3 to show the pattern of variation of body mass in this red deer population after this time.
Fig. 7.3
Name the type of force of natural selection that is acting on this population.
A selection pressure acted consistently over many years against red deer of medium body mass in a population.
Sketch a curve on Fig. 7.4 to show the pattern of variation of body mass in this red deer population after this time.
Fig. 7.4
Name the type of force of natural selection that is acting on this population.