Part 13 (2/2)
Mivart's work, but quote the above pa.s.sage as showing that Mr. Mivart will not, probably, be found to have left much unsaid that would appear to make against Mr. Darwin's theory. It is inc.u.mbent upon me both to see how far Mr. Mivart's objections are weighty as against Mr. Darwin, and also whether or not they tell with equal force against the view which I am myself advocating. I will therefore touch briefly upon the most important of them, with the purpose of showing that they are serious as against the doctrine that small fortuitous variations are the origin of species, but that they have no force against evolution as guided by intelligence and memory.
But before doing this, I would demur to the words used by Mr. Darwin, and just quoted above, namely, ”the theory of natural selection.” I imagine that I see in them the fallacy which I believe to run through almost all Mr. Darwin's work, namely, that ”natural selection” is a theory (if, indeed, it can be a theory at all), in some way accounting for the origin of variation, and so of species--”natural selection,” as we have already seen, being unable to ”induce variability,” and being only able to acc.u.mulate what--on the occasion of each successive variation, and so during the whole process--must have been originated by something else.
Again, Mr. Darwin writes--”In considering the origin of species it is quite conceivable that a naturalist, reflecting on the mutual affinities of organic beings, or their embryological relations, their geographical distribution, geological succession, and other such facts, might come to the conclusion that species had not been independently created, but had descended, like varieties from other species. Nevertheless, such a conclusion, even if well founded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world had been modified, so as to acquire that perfection of structure and co-adaptation which justly excites our admiration” (”Origin of Species,” p. 2, ed. 1876).
After reading the above we feel that nothing more satisfactory could be desired. We are sure that we are in the hands of one who can indeed tell us ”how the innumerable species inhabiting this world have been modified,” and we are no less sure that though others may have written upon the subject before, there has been, as yet, no satisfactory explanation put forward of the grand principle upon which modification has proceeded. Then follows a delightful volume, with facts upon facts concerning animals, all showing that species is due to successive small modifications acc.u.mulated in the course of nature. But one cannot suppose that Lamarck ever doubted this; for he can never have meant to say, that a low form of life made itself into an elephant at one or two great bounds; and if he did not mean this, he must have meant that it made itself into an elephant through the acc.u.mulation of small successive modifications; these, he must have seen, were capable of acc.u.mulation in the scheme of nature, though he may not have dwelt on the manner in which this is accomplished, inasmuch as it is obviously a matter of secondary importance in comparison with the origin of the variations themselves. We believe, however, throughout Mr. Darwin's book, that we are being told what we expected to be told; and so convinced are we, by the facts adduced, that in some way or other evolution must be true, and so grateful are we for being allowed to think this, that we put down the volume without perceiving that, whereas Lamarck DID adduce a great and general cause of variation, the insufficiency of which, in spite of errors of detail, has yet to be shown, Mr.
Darwin's main cause of variation resolves itself into a confession of ignorance.
This, however, should detract but little from our admiration for Mr.
Darwin's achievement. Any one can make people see a thing if he puts it in the right way, but Mr. Darwin made us see evolution, in spite of his having put it, in what seems to not a few, an exceedingly mistaken way. Yet his triumph is complete, for no matter how much any one now moves the foundation, he cannot shake the superstructure, which has become so currently accepted as to be above the need of any support from reason, and to be as difficult to destroy as it was originally difficult of construction. Less than twenty years ago, we never met with, or heard of, any one who accepted evolution; we did not even know that such a doctrine had been ever broached; unless it was that some one now and again said that there was a very dreadful book going about like a rampant lion, called ”Vestiges of Creation,”
whereon we said that we would on no account read it, lest it should shake our faith; then we would shake our heads and talk of the preposterous folly and wickedness of such shallow speculations. Had not the book of Genesis been written for our learning? Yet, now, who seriously disputes the main principles of evolution? I cannot believe that there is a bishop on the bench at this moment who does not accept them; even the ”holy priests” themselves bless evolution as their predecessors blessed Cleopatra--when they ought not. It is not he who first conceives an idea, nor he who sets it on its legs and makes it go on all fours, but he who makes other people accept the main conclusion, whether on right grounds or on wrong ones, who has done the greatest work as regards the promulgation of an opinion.
And this is what Mr. Darwin has done for evolution. He has made us think that we know the origin of species, and so of genera, in spite of his utmost efforts to a.s.sure us that we know nothing of the causes from which the vast majority of modifications have arisen--that is to say, he has made us think we know the whole road, though he has almost ostentatiously blindfolded us at every step of the journey.
But to the end of time, if the question be asked, ”Who taught people to believe in evolution?” there can only be one answer--that it was Mr. Darwin.
Mr. Mivart urges with much force the difficulty of STARTING any modification on which ”natural selection” is to work, and of getting a creature to vary in any definite direction. Thus, after quoting from Mr. Wallace some of the wonderful cases of ”mimicry” which are to be found among insects, he writes:-
”Now, let us suppose that the ancestors of these various animals were all dest.i.tute of the very special protection they at present possess, as on the Darwinian hypothesis we must do. Let it be also conceded that small deviations from the antecedent colouring or form would tend to make some of their ancestors escape destruction, by causing them more or less frequently to be pa.s.sed over or mistaken by their persecutors. Yet the deviation must, as the event has shown, in each case, be in some definite direction, whether it be towards some other animal or plant, or towards some dead or inorganic matter. But as, according to Mr. Darwin's theory, there is a constant tendency to indefinite variation, and as the minute incipient variations will be IN ALL DIRECTIONS, they must tend to neutralise each other, and at first to form such unstable modifications, that it is difficult, if not impossible, to see how such indefinite modifications of insignificant beginnings can ever build up a sufficiently appreciable resemblance to a leaf, bamboo, or other object for ”natural selection,” to seize upon and perpetuate. This difficulty is augmented when we consider--a point to be dwelt upon hereafter--how necessary it is that many individuals should be similarly modified simultaneously. This has been insisted on in an able article in the 'North British Review' for June 1867, p. 286, and the consideration of the article has occasioned Mr. Darwin” (”Origin of Species,” 5th ed., p. 104) ”to make an important modification in his views (”Genesis of Species,” p. 38).
To this Mr. Darwin rejoins:-
”But in all the foregoing cases the insects in their original state, no doubt, presented some rude and accidental resemblance to an object commonly found in the stations frequented by them. Nor is this improbable, considering the almost infinite number of surrounding objects, and the diversity of form and colour of the host of insects that exist” (”Natural Selection,” p. 182, ed. 1876).
Mr. Mivart has just said: ”It is difficult to see how such indefinite modifications of insignificant beginnings CAN EVER BUILD UP A SUFFICIENTLY APPRECIABLE RESEMBLANCE TO A LEAF, BAMBOO, OR OTHER OBJECT, FOR 'NATURAL SELECTION' TO WORK UPON.”
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: ”a.s.suming 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 pa.s.sage 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 antic.i.p.ate, 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 acc.u.mulate 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 acc.u.mulation 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 pa.s.sage:-
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