Although very many species have almost certainly been produced by steps not greater than those separating fine varieties; yet it may be maintained that some have been developed in a different and abrupt manner.
Nahiz eta, ia ziur, espezie asko eta asko, aldaki txikiak bereizten dituztenak baino urrats ez handiagoz sortu diren, hala ere, onar daiteke batzuk era ezberdinean eta bat-batean garatu direla.