Scientists find increasingly complex tools in progressively younger undisturbed layers at several sites. Which conclusion is best supported?
Each younger tool was made by a different new species.
Every older tool was made by the same individual ancestor.
Tool-making techniques developed over time across the sites examined.
Tool complexity determines the exact age of every fossil.
44 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.