A population of stick insects lives on shrubs that have green leaves for most of the year. Some of the insects are green and others are brown. Birds search the shrubs for stick insects.
A student concludes:
"Birds caused each brown stick insect to turn green. The insect then passed this change to its offspring."
Explain two errors in the student's conclusion.
Explain how the population could become mainly green over many generations.
Longer dry seasons cause most leaves on the shrubs to become brown for much of the year.
Suggest how this environmental change could affect the stick insect population.
85 exam-style questions on Edexcel GCSE Biology 4.1 Evolution and natural selection, covering 4.1.1 Work of Darwin and Wallace and 4.1.2 Resistant organisms and evolution. Each one has a worked solution and a mark scheme showing where the marks go.