Every colony trait — temperament, honey yield, disease resistance, swarming — varies across an apiary partly because of genes and partly because of environment (forage, weather, queen age, disease exposure). Heritability (h²) is the fraction of that visible variation which is due to additive genetic effects, and it sets a hard ceiling on how fast selective breeding can shift a trait.
UK bee breeders (e.g. BIBBA, B4 Project queen groups) typically report heritability estimates around h² ≈ 0.3–0.5 for temperament and hygienic behaviour, but much lower for traits like swarming or overwintering survival — which is why instrumental insemination programmes combine selection with careful record-keeping across many apiaries rather than relying on a single outstanding queen.
A 3D apiary of 100 instanced colonies where you requeen generation after generation, watching how heritability and selection strength together determine how far a trait can actually move.
Each hive's height and colour show its phenotype, split under the hood into a genetic breeding value and an environmental deviation. Selecting the gold-ringed top performers as breeders each round applies the breeder's equation R = h²S live.
Pick a trait for its realistic starting heritability, then override h² and selection strength yourself. Click "Requeen next generation" or switch on auto-advance and watch the gain chart climb — quickly for high-h² traits, barely at all for low ones.
Because Mendelian sampling reshuffles genes every generation, genetic variance never fully disappears — which is exactly why breeding programmes keep making slow gains decade after decade instead of hitting a wall after one round of selection.