Which part of the living system did you change?
Labs / Biology
Hardy-Weinberg
Green dots carry allele A, amber dots carry allele a, and split dots are heterozygotes. Each generation the alleles pair up at random, so the genotypes should settle at p², 2pq, and q². Switch on one evolutionary force at a time and watch when the real bars pull away from that prediction.
Labs / Biology / Hardy-Weinberg
Hardy-Weinberg
Green dots carry allele A, amber dots carry allele a, and split dots are heterozygotes. Each generation the alleles pair up at random, so the genotypes should settle at p², 2pq, and q². Switch on one evolutionary force at a time and watch when the real bars pull away from that prediction.
Why it matters
Why explore this?
Living systems are connected and constantly changing. This model makes one biological process visible so you can test how its parts affect one another.
Explore
Try the model
gen 0p 0.500q 0.500AA 0.250Aa 0.500aa 0.250χ² 0.00
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- With no force acting, why do the observed bars sit right on the dashed p², 2pq, q² outlines generation after generation?
- Turn on selection against aa. Which bar starts falling short of its prediction, and what happens to p over time?
- Mutation and migration both move p, but do they ever break the genotypes away from equilibrium the way selection does? Watch the χ² readout.
- Shrink the population to a handful of individuals. How wildly does p wander now, and can an allele vanish purely by chance?
- Start with p near 0.9 versus near 0.1 under the same force — does the population reach the same place, or does its starting point decide its fate?
Explain
Make sense of what happened
Explain the process as a chain: a change happens, the system responds, and that response affects what happens next. Use an observation from the model as evidence.
Check
Before you leave
How did the system respond?
How would you explain that response?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.