That is exactly parallel to the old-fashioned advocate of Natural Selection who reluctantly admits, on modern evidence—and mainly through the work of De Vries—great and rapid changes adapting animals to a new environment, but adds, “Anyhow, those that don’t change will be killed off.” Of course they will! But that isn’t the point. The point is that the killing off of the unfit is proved not to be the agent of change. The climate gets colder. Much thicker fleeces begin to appear. Such animals as don’t show the new thick fleeces begin to die out. Obviously!—But that doesn’t explain why the thicker fleeces began to appear. If you admit Mutation (the name for rapid change) or Saltatory Evolution (Evolution by jumps) poor old Natural Selection goes by the board.
In the same way Natural Selection does not mean that, upon a change of environment, things unsuitable to the new condition tend to disappear. Of course they do.
If there is a flood, fishes survive, cattle are drowned. The fishes are fitter to survive the flood than the cattle. And if the flood lasted long enough, there would at the end of it be plenty of fish and no cattle. But to talk of that as “Natural Selection” is to use the same word in two different senses.
The theory of Natural Selection as the agent of Evolution does not mean that floods drown cattle and don’t drown fish. We all know that. The theory means that successive floods turn cattle into fish—and that is a very different proposition!
The theory of Natural Selection does not mean that things die out when they cannot live; if it only meant that it would not be worth stating. It means that the chance of survival, through exceedingly small and inevitable slight differences between Parent and offspring, is the great cause producing the marvels in adaption and beauty and special action in a million forms which make up the life of this world. Its chief use has been to back up the denial of God, and now it has broken down the opponents of Design in the Universe must seek for a new reply.
They are still seeking it.
(5) Next note that the theory of Natural Selection implies a continual accumulation of fresh advantages; although for this there is no sort of necessity and, on a theory of blind chance, no possibility of such a thing. It is a mere gratuitous assumption with no reason behind it and all actual experiment against it. This is the point which Morgan (Professor of Experimental Zoology at Columbia University) so powerfully emphasizes in his critique of the Theory of Evolution which came out just after the war.
To apply the theory to that simple case of the animal on the tidal beach. Those with minute advantages over the average in the way of standing slightly longer immersion have survival-value over those who are only on or below the average. But why—by the mere blind selection of death—should the advantage accumulate from generation to generation? Why should new advantageous exceptions, each better than the last, appear in unbroken succession generation after generation?
(6) Lastly, there is the exceedingly important, the essential, point that, according to the theory of Natural Selection, each slight successive change in the whole series must give its possessor a survival-value. Not only must a fully formed flapper be an advantage (to a whale) over a leg, by the time it has become aquatic, but a half-formed flapper must be an advantage to the whale while it still uses the land. Clearly it was nothing of the kind. If transformism be true (which is not certain) then Design explains the leg into a flapper in spite of the intermediate disadvantages. If there is Design behind the transformation, if there is special protection for the heavily handicapped intermediate form, one can understand the possibility of it. Under Natural Selection it is impossible.
So much for the Implications of the Theory. I hope I have put them as clearly as may be, and accurately; not a very hard task, for it was an extremely crude and simple theory during its short life, and could be grasped (and refuted) by anyone.