And if we reflect on the vast diversity of the plants and animals which have been cultivated, and which have varied during all ages under the most different climates and treatment, we are driven to conclude that this great variability is due to our domestic productions having been raised under conditions of life not so uniform as, and somewhat different from, those to which the parent species had been exposed under nature.
Eta, gogoeta eginez, aro guztietan klima eta trataera ezberdinen pean gizakumeak hazi dituen eta aldatu diren landare eta animalien aniztasun ugaria kontuan hartzen badugu, honako ondorio honetara helduko gara, alegia, aldagarritasun handi honen kausa gure etxe-ekoizkinek jatorrizko guraso-espezieek naturan izaniko bizi-baldintza uniforme berberak ez izana dela, gureak erabat bestelako baldintzetan haziak izanik.