Safety and evidence boundary
Use fictional populations, cards, spreadsheets, or published aggregate data. Do not use population-genetic concepts to rank human groups or infer personal ancestry, intelligence, worth, or disease. Evolutionary mechanisms are population-level processes.
Explicit science instruction
For a two-allele locus under ideal assumptions—very large population, random mating, no selection, negligible mutation, no migration—allele frequencies remain stable and genotype expectations are p², 2pq, q².
The model is useful because deviations or changes motivate questions about mechanism, sampling and assumptions. It is a baseline, not a description of every real population.
Worked example with reasoning
If p=.6 and q=.4, expected genotype frequencies are AA=.36, Aa=.48, aa=.16. In N=500, expected counts are 180, 240, 80.
Guided question
Why is Hardy–Weinberg useful even though its assumptions are idealized?
Independent work
- Compute p², 2pq, q² for p=.8.
- Convert to counts for N=1,000.
- List five assumptions.
- Describe one cause of deviation and one cause of apparent deviation from sampling.
Misconception check
Hardy–Weinberg equilibrium is not “no change anywhere in biology”; it is a locus-specific population-genetic baseline under stated assumptions.
Formative understanding check
For p=.5, expected heterozygote frequency?
Worked response
2pq = .50.
Open-book formative practice only; not an official mastery attempt or grade.
Mentor evidence conference
Ask Archaemenes to challenge whether your population-level claim follows from the data and whether alternative evolutionary mechanisms remain possible.
Open ArchaemenesTeacher guidance
Foundation: use a p/q formula map. Core: calculate and interpret as expectations. Extended: test observed counts conceptually and distinguish assumption violation from sampling noise.
Preserve learning evidence
Keep calculations, graphs, models, corrections and limitations in the matching Week 28 evidence field.