# Explain how mass extinction events can lead to increased rates of speciation in surviving lineages.

> IB DP Biology Standard Level (2023 syllabus) — D4.2 Stability and change · Explain · 4 marks

## Mark scheme (4 marks)

1. Mass extinction events eliminate large numbers of species, reducing competition for resources / ecological niches
2. Surviving lineages can expand into newly vacated niches / undergo adaptive radiation
3. Populations of survivors may become geographically isolated in fragmented habitats, leading to allopatric speciation
4. Different selection pressures in different niches/environments drive divergence, eventually producing reproductive isolation and new species

## Key terms

- [mass extinction](https://www.gradenine.co.uk/glossary/mass-extinction)

## 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-mass-extinction-events-can-2bdbe755) · Published by Druglandscape Ltd.