Natural Selection almost inevitably causes much Extinction of the less improved forms of life and induces what I have called Divergence of Character.

He who believes that each being has been created as we now see it, must occasionally have felt surprise when he has met with an animal having habits and structure not at all in agreement.

This preservation of favourable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest.

It may be doubted whether any character can be named which is distinctive of a race and is constant.

I am fully convinced that species are not immutable; but that those belonging to what are called the same genera are lineal descendants of some other and generally extinct species, in the same manner as the acknowledged varieties of any one species are the descendants of that species. Furthermore, I am convinced that natural selection has been the most important, but not the exclusive, means of modification.

This preservation of favourable variations and the rejection of injurious variations, I call Natural Selection.