Scientists compared four species of cave beetle, J, K, L and M.
The table shows structural and molecular evidence for each pair of species.
| Pair of species | Matching structural characteristics out of 20 | Similarity in the molecules analysed (%) |
|---|---|---|
| J and K | 18 | 84 |
| J and L | 13 | 94 |
| J and M | 10 | 78 |
| K and L | 12 | 82 |
| K and M | 9 | 76 |
| L and M | 15 | 80 |
Scientists also produced an evolutionary model. Tracing the branches backwards from the living species gave the following results.
| Branches meeting in the model | Time before present in millions of years |
|---|---|
| J branch and L branch | 1.6 |
| combined J–L branch and K branch | 5.3 |
| combined J–K–L branch and M branch | 10.8 |
A scientist concluded that J and K are the most closely related pair of species.
Evaluate the scientist's conclusion. Use all the information provided.
81 exam-style questions on AQA GCSE Biology 6.4 Classification of living organisms, covering 6.4 Classification of living organisms. Each one has a worked solution and a mark scheme showing where the marks go.