How Natural Selection Works
Explain natural selection as the mechanism of evolution: heritable variation + competition for resources + differential survival and reproduction = change in allele frequency over generations
Suggested ages 12–14
Evidence of understanding
- Describes the four conditions required for natural selection to operate (variation, heritability, competition, selection)
- Applies the concept to a specific example (e.g. antibiotic resistance in bacteria, peppered moth)
- Explains why individuals with advantageous traits leave more offspring
- Distinguishes natural selection from evolution (selection is the mechanism; evolution is the result over many generations)
Assessment prompt
If How Natural Selection Works heard about bacteria becoming resistant to antibiotics, could they explain how that happened using natural selection — without the bacteria ‘choosing’ to change?
Standards alignment
MS-LS4-4
Next Generation Science Standards (NGSS) Middle School
Variation and natural selection
The national curriculum in England: Key stages 1 and 2 framework document · KS3
Genetic variation and evolution
The national curriculum in England: Key stages 1 and 2 framework document · KS3