3.7 Reproductive Success, Selection & Evolution

AQA Biology 7402 – 3.7.3 & 3.7.3.4 Genetic variation, selection and evolution

• Carefully sequenced lesson exploring how reproductive success drives changes in allele frequencies, forming the basis of evolution
• Explicit distinction between natural selection and reproductive success, addressing a key high-level misconception
• In-depth coverage of types of selection:
• stabilising (mean unchanged)
• directional (mean shifts)
• disruptive (extremes favoured)
• Strong focus on linking phenotype → survival → reproductive success → allele frequency change
• Active retrieval embedded throughout (Hardy–Weinberg recap, MWBs, hinge-style questioning)
• Students apply knowledge to real-world contexts (e.g. finches, iguanas, antibiotic resistance) to model evolutionary processes
• Emphasis on exam technique, including structured 6-mark explanations and use of key terminology (selection pressure, advantageous alleles, fitness)
• A* challenge built in through diagnostic true/false questions targeting misconceptions
• Develops disciplinary thinking: explaining evolutionary change step-by-step rather than describing outcomes