# Explain how convergent evolution can complicate the classification of organisms and how cladistics addresses this problem.

> IB DP Biology Standard Level (2023 syllabus) — A3.2 Classification and cladistics · Explain · 4 marks

## Mark scheme (4 marks)

1. Convergent evolution is the independent evolution of similar traits in unrelated lineages due to similar selection pressures.
2. These analogous (homoplastic) similarities can lead to organisms being incorrectly grouped together in traditional classification based on physical appearance/morphology.
3. Cladistics uses shared derived characters (synapomorphies) inherited from a common ancestor, rather than overall similarity, to group organisms.
4. Molecular sequence data (e.g. DNA or protein sequences) used in cladistics are less likely to be affected by convergent evolution, allowing more reliable determination of true evolutionary relationships.

## Key terms

- [convergent evolution](https://www.gradenine.co.uk/glossary/convergent-evolution)
- [cladistics](https://www.gradenine.co.uk/glossary/cladistics)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-convergent-evolution-can-complicate-fbba3bad) · Published by Druglandscape Ltd.