Describe how the fossil record provides evidence for evolution.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Scientists have studied fossils of horse-like animals found in rock layers of different ages. The oldest fossils show small animals with several toes, whilst more recent fossils show larger animals with a single hoof.
Model answer (4 marks)
Fossils are the remains or impressions of dead organisms that are found in rocks that are millions of years old.
Older or deeper rock layers contain fossils of horse‑like animals with several toes, while fossils in more recent layers show animals with a single hoof.
This shows that the inherited characteristics of the population changed gradually over time.
Because the fossils become more similar as the layers get closer together, the organisms are more closely related, giving evidence of evolutionary relationships.
Older or deeper rock layers contain fossils of horse‑like animals with several toes, while fossils in more recent layers show animals with a single hoof.
This shows that the inherited characteristics of the population changed gradually over time.
Because the fossils become more similar as the layers get closer together, the organisms are more closely related, giving evidence of evolutionary relationships.
Examiner tips
- Use the word "fossils" and explain they are millions of years old. Mention the change in toe number from older to newer layers. Show the gradual change and link it to evolution. State that similarity indicates relatedness.
Common mistakes
- Confusing fossils with living animals. Failing to link the change in characteristics to evolution. Using vague terms like "different" without specifying inherited traits. Not mentioning the sequence of layers or the idea of relatedness.
Mark scheme (4 marks)
- Fossils are the remains or impressions of dead organisms found in rocks that are millions of years old
- Fossils in older/deeper rock layers show organisms with different (inherited) characteristics to those in more recent layers, showing change over time
- The sequence of fossils shows a gradual change in the population's inherited characteristics over time (consistent with the definition of evolution)
- The more similar the fossils are (in terms of characteristics/DNA/structure), the more closely related the organisms are, showing evolutionary relationships
Key terms in this question
Related
- All Eduqas GCSE Biology revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
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