Vestiges of evolution

Suppose I had found an ape lying dead upon the ground, and it should be inquired how the ape happened to be in that place; I should hardly think of the answer I had before given, that for anything I knew, the ape might have always been there. … There must have existed, at some time, and at some place or other, some ancestors of this ape, who became adapted into the form which we find it actually to answer; adapted by natural selection to become different to other apes including ourselves. Clearly such an ape is evidence of evolution.