# A population of Arctic foxes lives in a snowy environment. Most Arctic foxes have white fur, but a small number have grey fur. Explain how natural selection could lead to white fur becoming more common in this population over many generations.

> Pearson Edexcel A-Level Biology A (9BI0) — Topic 7 Genetics, Populations, Evolution and Ecosystems · Explain · 5 marks

> Arctic foxes are predators that hunt prey such as lemmings. A fox's fur colour affects how well it is camouflaged against the snow.

## Mark scheme (5 marks)

1. There is variation in fur colour within the Arctic fox population (white and grey fur)
2. White fur provides better camouflage against the snow, so white foxes are better adapted to hunt prey / avoid being outcompeted
3. White foxes are more likely to survive / grey foxes are more likely to die (survival of the fittest / differential survival)
4. White foxes are more likely to reproduce and pass on the allele(s) / genes for white fur to offspring
5. Over many generations, the proportion of foxes with white fur increases in the population

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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/a-population-of-arctic-foxes-lives-96fa33db) · Published by Druglandscape Ltd.