B7: Variation, Natural Selection and Evolution
Official Cambridge & Imperial ESAT specification requirements for Variation, Natural Selection and Evolution on the Biology paper. Understand the syllabus boundaries, spot distractor traps engineered by examiners, and master the 2-step Sub-90 shortcuts that compress solve time well below the 88.8-second cutoff.
Official Syllabus Subtopics
Requirements specified in the UAT-UK framework
- 1Continuous variation (polygenic, normal distribution) vs discontinuous variation (monogenic, discrete categories)
- 2Natural selection mechanisms: random mutation, differential survival, and reproductive success
- 3Types of selection: directional (shifting mean), stabilising (reducing variance), and disruptive (bimodal distribution)
- 4Evolution of antibiotic resistance in bacterial populations
- 5Allopatric speciation (geographical reproductive isolation) vs sympatric speciation (ecological/behavioural isolation)
- 6Hardy-Weinberg equilibrium equations: p + q = 1 and p² + 2pq + q² = 1
Sub-90 Exam Speed Tips
How top candidates solve this spec under the 88.8s clock
When applying Hardy-Weinberg, always calculate q = √(q²) from the frequency of homozygous recessive individuals FIRST before calculating p = 1 - q and carrier frequency 2pq.
Natural selection acts on phenotypes, resulting in shifts in population allele frequencies over time.
Examiners engineer distractor options using common algebraic expansions and sign slips. Always test structural ratios or invariants before calculating arithmetic values.
Tested Topics in Specification B7
Master the individual question patterns and Sub-90 shortcuts for this specification.
Natural Selection, Antibiotic Resistance, Heterozygote Advantage & Speciation Sequence Foils
Instant Lamarckian eliminator: any statement saying an organism 'mutates in order to survive' or 'antibiotics cause mutations' is 100% FALSE. Mutation is always random and precedes the selection pressure.
Ready to Master Specification B7 Under Exam Conditions?
Practice timed questions under the authentic Pearson VUE interface with live split stopwatch pacing, dry-wipe scratchpad, and distractor forensics.