# Explain how the fossil record provides evidence for the theory of evolution by natural selection.

> IB DP Biology Standard Level (2023 syllabus) — A4.1 Evolution and speciation · Explain · 4 marks

## Mark scheme (4 marks)

1. Fossils show that organisms that lived in the past were different from organisms alive today, indicating that species have changed over time.
2. Fossils found in successive rock strata show a sequential change in form, demonstrating gradual change in lineages over geological time.
3. Transitional fossils show intermediate characteristics between ancestral and descendant groups, providing evidence that one group evolved from another.
4. The pattern of increasing diversity in the fossil record over time is consistent with populations diverging through natural selection acting on heritable variation.

## Key terms

- [fossil record](https://www.gradenine.co.uk/glossary/fossil-record)
- [natural selection](https://www.gradenine.co.uk/glossary/natural-selection)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-fossil-record-provides-a716af06) · Published by Druglandscape Ltd.