1 What selective pressures may have acted on early frog species that resulted in their becoming such good jumpers?
2 a) When amphibians left the water for life on land, why did they need stronger limbs to support the mass of the body?
b) What might have been the selective pressures that 'forced'some amphibians to leave their watery habitats?
3 a) Why do females of many animal species select males that are the biggest or strongest?
b) Why do female seaweed flies select large males?
4 Our ancestors, such as Australopithecus ramidus, grew to about half the height of today's Western male. Does this suggest that size selection has been important in human evolution? Justify your answer.
5 What evidence is there that some dinosaurs hatched their eggs like birds?
6 a) When did the greatest loss of plant and animal species occur?
