An experiment by William Muir compared egg productivity in hens, showing that a hyper-aggressive strain had been produced through individual selection, leading to many fatal attacks after only six generations; by implication, it could be argued that group selection must have been acting to prevent this in real life.
Un experimento feito por William Muir comparou a produtividade na posta de ovos nas galiñas, mostrando que se orixinara unha cepa hiperagresiva por selección individual; podería argumentarse que a selección de grupo debeu estar actuando para previr isto na vida real.