As each species tends by its geometrical rate of reproduction to increase inordinately in number; and as the modified descendants of each species will be enabled to increase by as much as they become more diversified in habits and structure, so as to be able to seize on many and widely different places in the economy of nature, there will be a constant tendency in natural selection to preserve the most divergent offspring of any one species.
eta espezie bakoitzeko ondorengo ezberdinduak, zenbat eta azturetan eta egituran gehiago ezberdindu, orduan eta ugaltzeko gaiago izanen direnez gero, era honetan naturaren ekonomian leku asko eta oso ezberdinak betetzeko modua izanik, hautespen naturalak joera iraunkorra izanen du zeinahi espezietako ondorengorik dibergenteenak kontserbatzera.