And indeed in natural systems such viruses display much lower virulence levels than do mutants of the same viruses that in laboratory culture readily outcompete non-virulent variants (or than do tick-transmitted viruses since ticks do bite dead rabbits).
E, de feito, nos sistemas naturais tales virus mostran uns niveis moito menores de virulencia que os mutantes do mesmo virus que en cultivo de laboratorio rapidamente vencen na competencia ás variantes non virulentas (ou que son virus transmitidos por carrachas, xa que as carrachas pican a coellos mortos).