The Hardy–Weinberg principle provides a mathematical model that predicts allele frequencies will not change from generation to generation
The Hardy–Weinberg principle is a mathematical model. It predicts that, in a stable population, the proportion of each allele (version of a gene) stays the same across generations.
Formula
p + q = 1; p² + 2pq + q² = 1
Real World
Cystic fibrosis affects about 1 in 2,500 newborns in the UK (q² = 0.0004), allowing geneticists to use Hardy–Weinberg to estimate that roughly 1 in 25 people are carriers (2pq ≈ 0.04).
Exam Focus
Start calculations by identifying q² from the homozygous recessive phenotype frequency, then square-root to find q before calculating p.
Evaluation Scaffold
A four-step framework for high-quality evaluation. Use this for 'assess', 'evaluate', and 'to what extent' questions.
How well did you know this?