A species of finch lives on the mainland. About 10 000 years ago a small number of these finches were blown to an island 200 km away. The seeds on the island are much harder than the seeds on the mainland. The finches on the island now have much deeper, stronger beaks than the finches on the mainland.
Figure shows the two populations of finches.
Figure: The mainland finch and the island finch, drawn to the same scale

Explain how the finches on the island evolved deeper, stronger beaks.
The island finches and the mainland finches are now classified as two different species.
Explain how scientists could show that they are two different species.
44 exam-style questions on AQA GCSE Biology 6.2 Variation and evolution, covering 6.2.1 Variation, 6.2.2 Evolution, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, and 6.2.5 Cloning. Each one has a worked solution and a mark scheme showing where the marks go.