An archaeologist finds a stone cutting tool in sediment on a volcanic island. Samples from two ash layers are radiometrically dated.
| Evidence | Excavation record |
|---|---|
| upper ash layer | above the tool; 0.64 million years old |
| stone tool | in sediment crossed by an animal burrow extending from the ground surface |
| lower ash layer | below the tool; 0.91 million years old |
A scientist concludes that the tool is between 0.64 and 0.91 million years old.
Evaluate the scientist's conclusion.
45 exam-style questions on Edexcel GCSE Biology 4.2 Evidence for evolution and classification, covering 4.2.1 Fossil evidence for human evolution, 4.2.2 Stone tool evidence for human evolution, 4.2.3 Pentadactyl limb as evidence, and 4.2.4 Three domains classification. Each one has a worked solution and a mark scheme showing where the marks go.