Science Ecosystems & Habitats Conceptual 12–14 yrs

How Natural Selection Works

自然选择的作用机制

Description

Explain natural selection as the mechanism of evolution: heritable variation + competition for resources + differential survival and reproduction = change in allele frequency over generations

Mastery Evidence

✓ 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 your child heard about bacteria becoming resistant to antibiotics, could they explain how that happened using natural selection — without the bacteria ‘choosing’ to change?