Digital Civilization

No one can draw any clear distinction between individual differences and slight varieties; or between more plainly marked varieties and subspecies, and species.

why should we doubt that variations in any way useful to beings, under their excessively complex relations of life, would be preserved, accumulated, and inherited?

The theory of natural selection, even if we looked no further than this, seems to me to be in itself probable. I have already recapitulated, as fairly as I could, the opposed difficulties and objections: now let us turn to the special facts and arguments in favour of the theory.

On the view that species are only strongly marked and permanent varieties, and that each species first existed as a variety, we can see why it is that no line of demarcation can be drawn between species, commonly supposed to have been produced by special acts of creation, and varieties which are acknowledged to have been produced by secondary laws. On this same view we can understand how it is that in each region where many species of a genus have been produced, and where they now flourish, these same species should present many varieties; for where the manufactory of species has been active, we might expect, as a general rule, to find it still in action; and this is the case if varieties be incipient species.

preserve the most divergent offspring

Hence during a long-continued course of modification, the slight differences, characteristic of varieties of the same species, tend to be augmented into the greater differences characteristic of species of the same genus.

New and improved varieties will inevitably supplant and exterminate the older, less improved and intermediate varieties; and thus species are rendered to a large extent defined and distinct objects.

This grand fact of the grouping of all organic beings seems to me utterly inexplicable on the theory of creation.

But why this should be a law of nature if each species has been independently created, no man can explain.

As natural selection acts solely by accumulating slight, successive, favourable variations, it can produce no great or sudden modification; it can act only by very short and slow steps

The wonder indeed is, on the theory of natural selection, that more cases of the want of absolute perfection have not been observed.

As natural selection acts by competition, it adapts the inhabitants of each country only in relation to the degree of perfection of their associates;

we believ