In 1858 Charles Darwin and Alfred Wallace jointly presented a scientific paper on evolution. One year later Darwin published On the Origin of Species.
Describe the contribution that Alfred Wallace made to the theory of evolution by natural selection.
Describe two ways in which the ideas of Darwin and Wallace have had an impact on modern biology.
Figure 1 is a simplified diagram of the bones in a human arm and in the front flipper of a seal.
State what is meant by a pentadactyl limb.
The human arm and the seal flipper are used for very different functions, but they contain the same arrangement of bones.
Explain how this provides evidence that humans and seals evolved from a common ancestor.
Suggest why the bones in the seal flipper are shorter and broader than the bones in the human arm.
A species of bird nests on pebble beaches. The eggs are speckled brown and grey, so they are very hard to see against the pebbles.
Give one benefit to the birds of the eggs being hard to see against the pebbles.
In the past, some birds in this species laid plain white eggs. Almost all birds in the population now lay speckled eggs.
Explain how natural selection could have caused this change.
