A friend reminds us of Catholic author G. K. Chesterton’s near-century-old response to one of the many fundamental problems with natural selection as a source of major genetic change:
Mr. H. G. Wells, in his wonderfully interesting and valuable “Outline of History,” takes one unnaturally simplified case of the growing of fur, or the change of the color of fur. He then implies that all other cases of natural selection are of the same kind. But they are not of the same kind, but of an exceedingly different and even opposite kind. If fur protects from cold, the longer fur will be a protection in the stronger cold. But any fur will be a protection in any cold. Any fur will be better than no fur; any fur will serve some of the purposes of fur. But it is not certain that any horn is better than no horn; it is very far from certain that any hump is better than no hump. It is very far from obvious that the first rudimentary suggestion of a horn, the first faint thickening which might lead through countless generations to the growth of a horn, would be of any particular use as a horn. And we must suppose, on the Darwinian hypothesis, that the hornless animal reached his horn through unthinkable gradations of what were, for all practical purposes, hornless animal. Why should one rhinoceros be so benevolent a Futurist as to start an improvement that could only help some much later rhinoceros to survive? And why on earth should its mere foreshadowing help the earlier rhinoceros to survive? This thesis can only explain variations when they discreetly refrain from varying very much. To the real riddles that arrest the eye, it has no answer that can satisfy the intelligence. For any child or man with his eyes open, I imagine, there is no creature that really calls for an answer, like a living riddle, so clearly as the bat. But if you will call up the Darwinian vision, of thousands of intermediary creatures with webbed feet that are not yet wings, their survival will seem incredible. A mouse can run, and survive; and a flitter-mouse can fly, and survive. But a creature that cannot yet fly, and can no longer run, ought obviously to have perished, by the very Darwinian doctrine which has to assume that he survived.
There are many other signs of this confession of failure, for which I have hardly left myself space. There is a chorus of Continental doubts; there is a multitude of destructive criticisms with which alone I could fill this article, even from my own very loose and general reading. But I will add a third reason of the same more general sort. The Darwinians have this mark of fighters for a lost cause, that they are perpetually appealing to sentiment and to authority. Put your bat or your rhinoceros simply and innocently as a child might put them, before the Darwinian, and he will answer by an appeal to authority. He will probably answer with the names of various German professors; he will not answer with any ordinary English words, explaining the point at issue. God condescended to argue with Job, but the last Darwinian will not condescend to argue with you. He will inform you of your ignorance; he will not enlighten your ignorance.
And I will add this point of merely personal experience of humanity: when men have a real explanation they explain it, eagerly and copiously and in common speech, as Huxley freely gave it when he thought he had it. When they have no explanation to offer, they give short dignified replies, disdainful of the ignorance of the multitude.
G. K. Chesterton, “Doubts About Darwinism,” Originally published in The Illustrated London News, 17th July 1920, (Source: G. K. Chesterton, Collected Works, Volume XXXII, The Illustrated London News 1920-1922, Ignatius Press, San Francisco, 1989. Pages 55-59.
The thing is, sneering has worked well for Darwinists for over a century because Darwinism produces only intellectual famine. Marxism got dumped sooner because it produced physical famine as well, which people take far more seriously.
See also: Yes, a Catholic can be a young Earth creationist in good faith
(briefly setting out how little the Catholic Church teaches about evolution, one way or the other)