That here, on the Wenlock Edge of time, a young American, seeking only frivolous amusement, should find a legitimate parentage as modern as though just caught in the Severn below, astonished him as much as though he had found Darwin himself. In the scale of evolution, one vertebrate was as good as another. For anything he, or any one else, knew, nine hundred and ninety nine parts of evolution out of a thousand lay behind or below the Pteraspis. To an American in search of a father, it mattered nothing whether the father breathed through lungs, or walked on fins, or on feet. Evolution of mind was altogether another matter and belonged to another science, but whether one traced descent from the shark or the wolf was immaterial even in morals. This matter had been discussed for ages without scientific result. La Fontaine and other fabulists maintained that the wolf, even in morals, stood higher than man; and in view of the late civil war, Adams had doubts of his own on the facts of moral evolution:--
"Tout bien considere, je te soutiens en somme, Que scelerat pour scelerat, Il vaut mieux etre un loup qu'un homme."
It might well be! At all events, it did not enter into the problem of Pteraspis, for it was quite certain that no complete proof of Natural Selection had occurred back to the time of Pteraspis, and that before Pteraspis was eternal void. No trace of any vertebrate had been found there; only starfish, shell-fish, polyps, or trilobites whose kindly descendants he had often bathed with, as a child on the shores of Quincy Bay.
That Pteraspis and shark were his cousins, great-uncles, or grandfathers, in no way troubled him, but that either or both of them should be older than evolution itself seemed to him perplexing; nor could he at all simplify the problem by taking the sudden back-somersault into Quincy Bay in search of the fascinating creature he had called a horseshoe, whose huge dome of shell and sharp spur of tail had so alarmed him as a child. In Siluria, he understood, Sir Roderick Murchison called the horseshoe a Limulus, which helped nothing. Neither in the Limulus nor in the Terebratula, nor in the Cestracion Philippi, any more than in the Pteraspis, could one conceive an ancestor, but, if one must, the choice mattered little. Cousinship had limits but no one knew enough to fix them. When the vertebrate vanished in Siluria, it disappeared instantly and forever. Neither vertebra nor scale nor print reappeared, nor any trace of ascent or descent to a lower type. The vertebrate began in the Ludlow shale, as complete as Adams himself--in some respects more so--at the top of the column of organic evolution: and geology offered no sort of proof that he had ever been anything else. Ponder over it as he might, Adams could see nothing in the theory of Sir Charles but pure inference, precisely like the inference of Paley, that, if one found a watch, one inferred a maker. He could detect no more evolution in life since the Pteraspis than he could detect it in architecture since the Abbey. All he could prove was change. Coal-power alone asserted evolution--of power--and only by violence could be forced to assert selection of type.