It must be emphasised that this criterion reflects fossil evidence, and is totally independent of whether the taxa had been subject to selection at all, which all living populations continuously are, whether they remain genetically unchanged or not.
Debe salientarse que este criterio reflicte a evidencia fósil, e é totalmente independente de se os taxons estiveron suxeitos a selección, á cal todas as poboacións vivas están continuamente sometidas, tanto se permanecen sen cambiar xeneticamente coma se non.