Origin of Species Variorum

character; for ... the more organic beings diverge in structure, habits, and constitution, by so much a greater number can be supported on the same area,— of which we see proof by looking to the inhabitants of any small spot or to naturalised productions. Therefore, during the modification of the descendants of any one species, and during the incessant struggle of all species to increase in numbers, the more diversified these descendants become, the better will be their chance of succeeding in the battle for life. Thus the small differences distinguishing varieties of the same species, .. steadily tend to increase till they come to equal the greater differences between species of the same genus, or even of distinct genera.

We have seen that it is the common, the widely-diffused, and widely-ranging species, belonging to the larger genera within each class, which vary most; and these .. tend to transmit to their modified offspring that superiority which now makes them dominant in their own countries. Natural selection, as has just been remarked, leads to divergence of character and to much extinction of the less improved and intermediate forms of life. On these principles, .. the nature of the affinities, and the generally well-defined distinctions of the innumerable organic beings in each class throughout the world, may be explained. It is a truly wonderful fact— the wonder of which we are apt to overlook from familiarity— that all animals and all plants throughout all time and space should be related to each other in group subordinate to group, in the manner which we everywhere behold— namely, varieties of the same species most closely related together, species of the same genus less closely and unequally related together, forming sections and sub-genera, species of distinct genera much less closely related, and genera related