Natural Selection, if it had been the agent of Evolution, would have prevented the formation of fixed types.
In the old materialist days when Natural Selection was triumphing, its supporters used to say, as we have seen, that it acted “until equilibrium was reached by the organism conforming to its environment.” That was typical of their hiding the weakness of their case under vague phrases which, closely analysed, proved self-contradictory.
If Natural Selection be the Agent of Evolution stability can never be reached. There is always some slight proportion of beings rather more suited to survive than the mass of its fellows, and that fact should cause a perpetual change rendering stability impossible.
A water-mammal has not “reached stability” when it can stay under water ten minutes, or an hour, or two hours. According to Natural Selection, it ought to progress unceasingly to longer and longer capacities of submersion. A swallow has not “reached stability” by Natural Selection when it flies sixty miles an hour; it ought to fly faster and faster with the process of time. It may well have reached stability in the sense that it is suited to its lot and makes no further effort. It may well have reached stability in the sense that its end has been achieved, its design completed. But if it got its fast flight only because a slightly faster minority of swallows always outlive and outbreed their slower rivals, by an assumed perpetual accumulation of little additions of speed, why should the process stop at the bird’s present capacity? Of course the series is a diminishing one. Each increment of speed is at a higher cost than the last. But no fast-flying bird has nearly reached a theoretical limit of speed—nor shows any tendency to reach it. Granted Design then an End,—a Fixed Type—a Normal to which individuals are planned and to which freak types tend to return—is explicable. Those who cannot bear the idea of Design, that is of a Creator implanting inherent powers, must try to invent some new theory which will allow of Fixed Types without Design. But if Fixed Types exist they cannot be due to Natural Selection, for Natural Selection and Fixed Types are contradictory terms.
If Natural Selection be true, then what we call a pig is but a fleeting vision; all the past he has been becoming a pig, and all the future he will spend evolving out of pigdom, and pig is but a moment’s phase in the eternal flux, while, all around us should be quarter-pigs, half-pigs, near-pigs, all-but-pigs, slightly super-pigs, just beginning—and so on. But there aren’t. There are just pigs. In other words, the evidence is all in favour of Fixed Types and all against a ceaseless process of change.
(1) We have the evidence of our senses that we are surrounded by Fixed Types, and are Fixed Types ourselves. We have all about us species, including man, which remain distinct species during all our experience and as far back as historical record can carry us.
(2) If that were not sufficient we have Fixed Types, and nothing but Fixed Types, in thousands and thousands (and continuing for what seem to be immense stretches of time) in the geological record.
(3) That same geological record shows us, not a gradual turning of one type into another, not a gradual ascent like an inclined plane—which Natural Selection would demand—but a series of steps with sharp divisions between.
These three arguments from experience are conclusive.
1. The First Argument from Evidence against Natural Selection: