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
Population genetics tracks how allele and genotype frequencies change across generations. For a diploid locus with alleles A and a, each individual contributes two allele copies. If counts are AA, Aa, aa, then frequency of A is (2AA + Aa)/(2N), and a is (2aa + Aa)/(2N).
Allele frequency belongs to a population sample; an individual does not have an “allele frequency.”
Vocabulary: allele frequency; genotype frequency; population; gene pool; diploid; generation.
Worked example with reasoning
In 100 fictional organisms: 36 AA, 48 Aa, 16 aa. A copies = 72+48=120 of 200, so p(A)=0.60; q(a)=0.40. Genotype frequencies are .36, .48, .16.
Guided question
Why do we divide allele counts by 2N in a diploid population?
Independent work
- Calculate frequencies for 25 AA, 50 Aa, 25 aa.
- Verify p+q=1.
- Distinguish allele and genotype frequency.
- State sampling limits.
Misconception check
A common allele is not necessarily dominant, advantageous, ancestral, or “better.” Frequency and dominance are different concepts.
Formative understanding check
If p=.7 in a two-allele model, q?
Worked response
.3.
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 allele-count tokens. Core: calculate from counts and verify totals. Extended: compare sample versus true population frequency and sampling error.
Preserve learning evidence
Keep calculations, graphs, models, corrections and limitations in the matching Week 28 evidence field.