The similarities and homologies of structure existing between man
and other animals, and between other animals and still others, are
not accidental and causeless. They are not resemblances scattered
arbitrarily among the multitudinous forms of life by the capricious
levities of chance. That all animals commence existence as an egg
and are all made up of cells composed of the same protoplasmic
substance, and all inhale oxygen and exhale carbon dioxide, and are
all seeking pleasure and seeking to avoid pain, are more than
ordinary facts. They are filled with inferences. That vertebrate
animals, differing in externals as widely as herring and Englishmen,
are all built according to the same fundamental plan, with
marrow-filled backbones and exactly two pairs of limbs branching in
the same way, is an astonishing coincidence. That the wing of the
bird, the foreleg of the dog, the flipper of the whale, and the
fore-limb of the toad and crocodile, have essentially the same bones
as the human arm has is a fact which may be without significance to
blind men, but to no one else. The metamorphosis of the frog from a
fish, of the insect from a worm, and of a poet from a senseless
cell, are transformations simply marvellous in meaning. And it is
not easy, since Darwin, to understand how such lessons could remain
long unintelligible, even to stones and simpletons. Not many
generations have passed, however, since these revelations, now so
distinct and wonderful, fell on the listless minds of men as
ineffectually as the glories of the flower fall on the sightless
sockets of the blind.
It is hardly two generations since the highest intelligences on the
earth conceived that not only the different varieties of men—the
black, the white, and the orange—but all the orders and genera of
the animal world, and not only animals, but plants, had all been
somehow simultaneously and arbitrarily brought into existence in
some indistinct antiquity, and that they had from the beginning all
existed with practically the same features and in approximately the
same conditions as those with which and in which they are found
to-day. The universe was conceived to be a fixed and stupid
something, born as we see it, incapable of growth, and indulging in
nothing but repetitions. There were no necessary coherencies and
consanguinities, no cosmical tendencies operating eternally and
universally. All was whimsical and arbitrary. It was not known that
anything had grown or evolved. All things were believed to have been
given beginning and assigned to their respective places in the
universe by a potential and all-clever creator. The serpent was
limbless because it had officiously allowed Eve to include in her
dietary that which had been expressly forbidden. The quadruped
walked with its face towards the earth as a structural reminder of
its subjection to the biped, who was supposed to be especially
skilled in keeping his eyes rolled heavenward. The flowers flung out
their colours, not for the benefit of the bugs and bees, and the
stars paraded, not because they were moved to do so by their own
eternal urgings, but because man had eyes capable of being affected
by them. Man was an erect and featherless vertebrate because his
hypothetical maker was erect and featherless. (I wonder whether, if
a clam should conceive a creator, it would have the magnanimity to
make him an insect or a vertebrate, or anything other than a great
big clam.)