IB ESS SL 3.1.4 Natural Selection Question Bank
Explain natural selection as differential survival and reproduction of heritable variation.
- Syllabus
- First assessment 2026
- Course
- ESS SL
- Level
- SL
Explain natural selection as differential survival and reproduction of heritable variation.

Figure:Continents and species diversity over time
Outline the role of natural selection in increasing the diversity of species.
Outline the role of natural selection in increasing the diversity of species.
natural selection (resulting from changing environment) acts on existing genetic variation (that has arisen through mutations over the eons); natural selection increases the survival of fittest genetic variations/traits; these traits are heritable/passed onto offspring / selected individuals will have higher reproduction potential / so species will adapt to different environments; the proportion of these traits may increase in some populations/in subsequent generations; which can lead to speciation/increasing species diversity if there is reproductive isolation;