I am not apt to follow blindly the lead of other men

... if variations useful to any organic being do occur, assuredly individuals thus characterized will have the best chance of being perserved in the struggle for life; and from the strong principle of inheritance they will tend to produce offsping similarly characterized. This principle of preservation, I have called, for the sake of brevity, Natural Selection.

Jealousy was plainly exhibited when I fondled a large doll, and when I weighed his infant sister, he being then 15? months old. Seeing how strong a feeling of jealousy is in dogs, it would probably be exhibited by infants at any earlier age than just specified if they were tried in a fitting manner

The expression often used by Mr. Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient.

It's not the strongest, but the most adaptable that survive.

Not one great country can be named, from the polar regions in the north to New Zealand in the south, in which the aborigines do not tattoo themselves.

The fact of evolution is the backbone of biology, and biology is thus in the peculiar position of being a science founded on an improved theory, is it then a science or faith?