Honey bee breeding programmes select a small number of outstanding breeder queens and mate their daughter queens with a pool of drone fathers at a drone congregation area (DCA) or via instrumental insemination. Because only a fraction of the population contributes genes each generation, the population's effective size (Nₑ) is usually much smaller than its census size — and small Nₑ drives up the inbreeding coefficient (F) over successive generations, eroding genetic diversity.
Nₑ = 4·Nq·Nd / (Nq+Nd), where Nq is breeder queens and Nd is effective drone fathers.ΔF = 1/(2Nₑ), compounding to F(t) = 1-(1-ΔF)^t. Hive colour and the shrinking allele-cloud above the DCA track rising F and falling diversity.Because queens mate with 10–20 drones in flight, honey bee colonies are naturally polyandrous "super-organisms" with higher within-colony genetic diversity than most animals — but the queen line itself can still become dangerously inbred if breeding programmes repeatedly select from a narrow set of matrilines without tracking pedigree and SNP-based relatedness.
A 3D apiary breeding population where the number of selected breeder queens and drone fathers, plus the mating scheme, drive effective population size, inbreeding coefficient and genetic diversity over simulated generations.
Effective population size (Nₑ) depends on both breeder queen and drone father numbers; small Nₑ compounds inbreeding each generation (ΔF = 1/2Nₑ), visibly eroding the allele-diversity cloud above the drone congregation area.
Adjust breeder queens, drone fathers and mating scheme, then scrub the generation slider or press ▶ to auto-advance. Watch hive colour shift from green toward red as inbreeding coefficient F climbs.
Modern queen-breeding programmes now use SNP genotyping panels to estimate real pedigree-based relatedness directly from DNA, catching inbreeding trends years before symptoms like spotty brood patterns appear.