# A population of Galápagos finches living on an island with large, hard seeds includes individuals with different beak sizes. Explain how natural selection could lead to finches with larger, stronger beaks becoming more common in this population over many generations.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 2.6 Adaptation and natural selection · Explain · 5 marks

> The Galápagos finches feed mainly on seeds found on the island. Individuals in the population show variation in beak size and strength. Only large, strong beaks can crack open the hard seeds efficiently.

## Mark scheme (5 marks)

1. There is variation in beak size and strength within the population
2. Finches with larger, stronger beaks are better adapted to crack open the hard seeds and so obtain more food / energy
3. Finches with larger, stronger beaks are more likely to survive (and reproduce) — survival of the fittest
4. Finches with larger, stronger beaks are more likely to reproduce and pass on the alleles / genes for larger, stronger beaks to their offspring
5. Over many generations, the proportion / frequency of finches with larger, stronger beaks increases in the population

## Key terms

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

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](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-gal-pagos-finches-living-45729e5b) · Published by Druglandscape Ltd.