The answer is, that “natural selection” did not begin to work until, from unknown causes, an appreciable resemblance had nevertheless been presented. I think the reader will agree with me that the development of the lowest life into a creature which bears even “a rude resemblance” to the objects commonly found in the station in which it is moving in its present differentiation, requires more explanation than is given by the word “accidental.”
Mr. Darwin continues: “As some rude resemblance is necessary for the first start,” &c.; and a little lower he writes: “Assuming that an insect originally happened to resemble in some degree a dead twig or a decayed leaf, and that it varied slightly in many ways, then all the variations which rendered the insect at all more like any such object, and thus favoured its escape, would be preserved, while other variations would be neglected, and ultimately lost, or if they rendered the insect at all less like the imitated object, they would be eliminated.”
But here, again, we are required to begin with Natural Selection when the work is already in great part done, owing to causes about which we are left completely in the dark; we may, I think, fairly demur to the insects originally happening to resemble in some degree a dead twig or a decayed leaf. And when we bear in mind that the variations, being supposed by Mr. Darwin to be indefinite, or devoid of aim, will appear in every direction, we cannot forget what Mr. Mivart insists upon, namely, that the chances of many favourable variations being counteracted by other unfavourable ones in the same creature are not inconsiderable. Nor, again, is it likely that the favourable variation would make its mark upon the race, and escape being absorbed in the course of a few generations, unless—as Mr. Mivart elsewhere points out, in a passage to which I shall call the reader’s attention presently—a larger number of similarly varying creatures made their appearance at the same time than there seems sufficient reason to anticipate, if the variations can be called fortuitous.
“There would,” continues Mr. Darwin, “indeed be force in Mr. Mivart’s objection if we were to attempt to account for the above resemblances, independently of ‘natural selection,’ through mere fluctuating variability; but as the case stands, there is none.”
This comes to saying that, if there was no power in nature which operates so that of all the many fluctuating variations, those only are preserved which tend to the resemblance which is beneficial to the creature, then indeed there would be difficulty in understanding how the resemblance could have come about; but that as there is a beneficial resemblance to start with, and as there is a power in nature which would preserve and accumulate further beneficial resemblance, should it arise from this cause or that, the difficulty is removed. But Mr. Mivart does not, I take it, deny the existence of such a power in nature, as Mr. Darwin supposes, though, if I understand him rightly, he does not see that its operation upon small fortuitous variations is at all the simple and obvious process, which on a superficial view of the case it would appear to be. He thinks—and I believe the reader will agree with him—that this process is too slow and too risky. What he wants to know is, how the insect came even rudely to resemble the object, and how, if its variations are indefinite, we are ever to get into such a condition as to be able to report progress, owing to the constant liability of the creature which has varied favourably, to play the part of Penelope and undo its work, by varying in some one of the infinite number of other directions which are open to it—all of which, except this one, tend to destroy the resemblance, and yet may be in some other respect even more advantageous to the creature, and so tend to its preservation. Moreover, here, too, I think (though I cannot be sure), we have a recurrence of the original fallacy in the words—“If we were to account for the above resemblances, independently of ‘natural selection,’ through mere fluctuating variability.” Surely Mr. Darwin does, after all, “account for the resemblances through mere fluctuating variability,” for “natural selection” does not account for one single variation in the whole list of them from first to last, other than indirectly, as shewn in the preceding chapter.
It is impossible for me to continue this subject further; but I would beg the reader to refer to other paragraphs in the neighbourhood of the one just quoted, in which he may—though I do not think he will—see reason to think that I should have given Mr. Darwin’s answer more fully. I do not quote Mr. Darwin’s next paragraph, inasmuch as I see no great difficulty about “the last touches of perfection in mimicry,” provided Mr. Darwin’s theory will account for any mimicry at all. If it could do this, it might as well do more; but a strong impression is left on my mind, that without the help of something over and above the power to vary, which should give a definite aim to variations, all the “natural selection” in the world would not have prevented stagnation and self-stultification, owing to the indefinite tendency of the variations, which thus could not have developed either a preyer or a preyee, but would have gone round and round and round the primordial cell till they were weary of it.
As against Mr. Darwin, therefore, I think that the objection just given from Mr. Mivart is fatal. I believe, also, that the reader will feel the force of it much more strongly if he will turn to Mr. Mivart’s own pages. Against the view which I am myself supporting, the objection breaks down entirely, for grant “a little dose of judgement and reason” on the part of the creature itself—grant also continued personality and memory—and a definite tendency is at once given to the variations. The process is thus started, and is kept straight, and helped forward through every stage by “the little dose of reason,” &c., which enabled it to take its first step. We are, in fact, no longer without a helm, but can steer each creature that is so discontented with its condition, as to make a serious effort to better itself, into some—and into a very distant—harbour.
It has been objected against Mr. Darwin’s theory that if all species and genera have come to differ through the accumulation of minute but—as a general rule—fortuitous variations, there has not been time enough, so far as we are able to gather, for the evolution of all existing forms by so slow a process. On this subject I would again refer the reader to Mr. Mivart’s book, from which I take the following:—
“Sir William Thompson has lately advanced arguments from three distinct lines of inquiry agreeing in one approximate result. The three lines of inquiry are—(1) the action of the tides upon the earth’s rotation; (2) the probable length of time during which the sun has illuminated this planet; and (3) the temperature of the interior of the earth. The result arrived at by these investigations is a conclusion that the existing state of things on the earth, life on the earth, all geological history showing continuity of life, must be limited within some such period of past time as one hundred million years. The first question which suggests itself, supposing Sir W. Thompson’s views to be correct, is: Has this period been anything like enough for the evolution of all organic forms by ‘natural selection’? The second is: Has the period been anything like enough for the deposition of the strata which must have been deposited if all organic forms have been evolved by minute steps, according to the Darwinian theory?” (“Genesis of Species,” p. 154).
Mr. Mivart then quotes from Mr. Murphy—whose work I have not seen—the following passage:—