STEM
DriftForge
Selection has a direction; drift is pure luck — and in a small population, luck wins. DriftForge runs evolution on synthetic beetles: predict an allele’s frequency after a generation of selection, drift, migration or a bottleneck, then reveal the maths — and run 24 generations yourself to watch selection trace a smooth curve while drift wanders and a crash loses an allele by chance. Ages 15–18.
▶ Play it nowBuilt for sittings of about 25 minutes on the screen. That is our design budget, not a measurement.
#3a7d44 Characters who teach
Meet the cast
DriftForge is for ages 15–18 — no illustrated cast; the 'characters' are the four forces that move an allele frequency across generations. Selection is directional and deterministic: fitter genotypes leave more copies, so a beneficial allele climbs predictably (and a harmful one falls). Drift is the opposite — random sampling of which finite individuals happen to breed, with no direction, and it swings harder the smaller the population. A bottleneck is drift turned to maximum by a population crash, so an allele can fix or vanish by pure luck. Migration is gene flow that pulls a population toward the frequency of its arrivals. Selection and migration are exact arithmetic; drift is a seeded binomial sample, reproducible on-device.
Selection
The directional, deterministic force — fitter genotypes leave more copies, so a beneficial allele rises predictably (and a harmful one falls); run it again and you get the same climb
Drift
Random change from finite sampling — no direction, and larger swings the smaller the population; with drift you predict the SPREAD, not a single value
The bottleneck
Drift turned to maximum by a population crash — an allele can fix or vanish by pure luck regardless of fitness, so crashes lose genetic variety
Migration
Gene flow that pulls a population toward the frequency of its arrivals, keeping far-apart groups genetically similar until it is cut off
What's inside
Learning goal
Selection has a direction; drift is pure luck — and in a small population, luck wins. DriftForge runs evolution on synthetic beetles: predict an allele’s frequency after a generation of selection, drift, migration or a bottleneck, then reveal the maths — and run 24 generations yourself to watch selection trace a smooth curve while drift wanders and a crash loses an allele by chance. Ages 15–18.
How DriftForge handles your kid's data
- ✅ All progress, settings, and AI-generated content stays on the device
- ✅ No analytics, no tracking, no third-party SDKs
- ✅ Free — no ads, no in-app purchases
- ✅ No personal information collected from children — in line with COPPA (updated by the 2026 FTC amendments)
- ✅ No chat with strangers — play-together rooms use a short code and preset emotes, never typed messages