Part 14 (1/2)
”Darwin justly mentions the greyhound as being equal to any natural species in the perfect co-ordination of its parts, 'all adapted for extreme fleetness and for running down weak prey.' Yet it is an artificial species (and not physiologically a species at all) formed by a long-continued selection under domestication; and there is no reason to suppose that any of the variations which have been selected to form it have been other than gradual and almost imperceptible.
Suppose that it has taken five hundred years to form the greyhound out of his wolf-like ancestor. This is a mere guess, but it gives the order of magnitude. Now, if so, how long would it take to obtain an elephant from a protozoon or even from a tadpole-like fish? Ought it not to take much more than a million times as long?” (”Genesis of Species,” p. 155).
I should be very sorry to p.r.o.nounce any opinion upon the foregoing data; but a general impression is left upon my mind, that if the differences between an elephant and a tadpole-like fish have arisen from the acc.u.mulation of small variations that have had no direction given them by intelligence and sense of needs, then no time conceivable by man would suffice for their development. But grant ”a little dose of reason and judgement,” even to animals low down in the scale of nature, and grant this, not only during their later life, but during their embryological existence, and see with what infinitely greater precision of aim and with what increased speed the variations would arise. Evolution entirely unaided by inherent intelligence must be a very slow, if not quite inconceivable, process. Evolution helped by intelligence would still be slow, but not so desperately slow. One can conceive that there has been sufficient time for the second, but one cannot conceive it for the first.
I find from Mr. Mivart that objection has been taken to Mr. Darwin's views, on account of the great odds that exist against the appearance of any given variation at one and the same time, in a sufficient number of individuals, to prevent its being obliterated almost as soon as produced by the admixture of unvaried blood which would so greatly preponderate around it; and indeed the necessity for a nearly simultaneous and similar variation, or readiness so to vary on the part of many individuals, seems almost a postulate for evolution at all. On this subject Mr. Mivart writes:-
”The 'North British Review' (speaking of the supposition that species is changed by the survival of a few individuals in a century through a similar and favourable variation) says -
”'It is very difficult to see how this can be accomplished, even when the variation is eminently favourable indeed; and still more, when the advantage gained is very slight, as must generally be the case.
The advantage, whatever it may be, is utterly outbalanced by numerical inferiority. A million creatures are born; ten thousand survive to produce offspring. One of the million has twice as good a chance as any other of surviving, but the chances are fifty to one against the gifted individuals being one of the hundred survivors.
No doubt the chances are twice as great against any other individual, but this does not prevent their being enormously in favour of SOME average individual. However slight the advantage may be, if it is shared by half the individuals produced, it will probably be present in at least fifty-one of the survivors, and in a larger proportion of their offspring; but the chances are against the preservation of any one ”sport” (i.e., sudden marked variation) in a numerous tribe. The vague use of an imperfectly-understood doctrine of chance, has led Darwinian supporters, first, to confuse the two cases above distinguished, and secondly, to imagine that a very slight balance in favour of some individual sport must lead to its perpetuation. All that can be said is that in the above example the favoured sport would be preserved once in fifty times. Let us consider what will be its influence on the main stock when preserved. It will breed and have a progeny of say 100; now this progeny will, on the whole, be intermediate between the average individual and the sport. The odds in favour of one of this generation of the new breed will be, say one and a half to one, as compared with the average individual; the odds in their favour will, therefore, be less than that of their parents; but owing to their greater number the chances are that about one and a half of them would survive. Unless these breed together--a most improbable event--their progeny would again approach the average individual; there would be 150 of them, and their superiority would be, say in the ratio of one and a quarter to one; the probability would now be that nearly two of them would survive, and have 200 children with an eighth superiority. Rather more than two of these would survive; but the superiority would again dwindle; until after a few generations it would no longer be observed, and would count for no more in the struggle for life than any of the hundred trifling advantages which occur in the ordinary organs.
”'An ill.u.s.tration will bring this conception home. Suppose a white man to have been wrecked on an island inhabited by negroes, and to have established himself in friendly relations with a powerful tribe, whose customs he has learnt. Suppose him to possess the physical strength, energy, and ability of a dominant white race, and let the food of the island suit his const.i.tution; grant him every advantage which we can conceive a white to possess over the native; concede that in the struggle for existence, his chance of a long life will be much superior to that of the native chiefs; yet from all these admissions there does not follow the conclusion, that after a limited or unlimited number of generations, the inhabitants of the island will be white. Our s.h.i.+pwrecked hero would probably become king; he would kill a great many blacks in the struggle for existence; he would have a great many wives and children . . . In the first generation there will be some dozens of intelligent young mulattoes, much superior in average intelligence to the negroes. We might expect the throne for some generations to be occupied by a more or less yellow king; but can any one believe that the whole island will gradually acquire a white, or even a yellow population? . . . Darwin says, that in the struggle for life a grain may turn the balance in favour of a given structure, which will then be preserved. But one of the weights in the scale of nature is due to the number of a given tribe. Let there be 7000 A's and 7000 B's representing two varieties of a given animal, and let all the B's, in virtue of a slight difference of structure, have the better chance by one-thousandth part. We must allow that there is a slight probability that the descendants of B will supplant the descendants of A; but let there be 7001 A's against 7000 B's at first, and the chances are once more equal, while if there be 7002 A's to start, the odds would be laid on the A's. Thus they stand a greater chance of being killed; but, then, they can better afford to be killed. The grain will only turn the scales when these are very nicely balanced, and an advantage in numbers counts for weight, even as an advantage in structure. As the numbers of the favoured variety diminish, so must its relative advantages increase, if the chance of its existence is to surpa.s.s the chance of its extinction, until hardly any conceivable advantage would enable the descendants of a single pair to exterminate the descendants of many thousands, if they and their descendants are supposed to breed freely with the inferior variety, and so gradually lose their ascendancy,'” (”North British Review,” June 1867, p. 286 ”Genesis of Species,” p. 64, and onwards).
Against this it should be remembered that there is always an antecedent probability that several specimens of a given variation would appear at one time and place. This would probably be the case even on Mr. Darwin's hypothesis, that the variations are fortuitous; if they are mainly guided by sense of need and intelligence, it would almost certainly be so, for all would have much the same idea as to their well-being, and the same cause which would lead one to vary in this direction would lead not a few others to do so at the same time, or to follow suit. Thus we see that many human ideas and inventions have been conceived independently but simultaneously. The chances, moreover, of specimens that have varied successfully, intermarrying, are, I think, greater than the reviewer above quoted from would admit. I believe that on the hypothesis that the variations are fortuitous, and certainly on the supposition that they are intelligent, they might be looked for in members of the same family, who would hence have a better chance of finding each other out.
Serious as is the difficulty advanced by the reviewer as against Mr.
Darwin's theory, it may be in great measure parried without departing from Mr. Darwin's own position, but the ”little dose of judgement and reason” removes it, absolutely and entirely. As for the reviewer's s.h.i.+pwrecked hero, surely the reviewer must know that Mr. Darwin would no more expect an island of black men to be turned white, or even perceptibly whitened after a few generations, than the reviewer himself would do so. But if we turn from what ”might” or what ”would” happen to what ”does” happen, we find that a few white families have nearly driven the Indian from the United States, the Australian natives from Australia, and the Maories from New Zealand.
True, these few families have been helped by immigration; but it will be admitted that this has only accelerated a result which would otherwise, none the less surely, have been effected.
There is all the difference between a sudden sport, or even a variety introduced from a foreign source, and the gradual, intelligent, and, in the main, steady, growth of a race towards ends always a little, but not much, in advance of what it can at present compa.s.s, until it has reached equilibrium with its surroundings. So far as Mr.
Darwin's variations are of the nature of ”sport,” i.e., rare, and owing to nothing that we can in the least a.s.sign to any known cause, the reviewer's objections carry much weight. Against the view here advocated, they are powerless.
I cannot here go into the difficulties of the geologic record, but they too will, I believe, be felt to be almost infinitely simplified by supposing the development of structure and instinct to be guided by intelligence and memory, which, even under unstable conditions, would be able to meet in some measure the demands made upon them.
When Mr. Mivart deals with evolution and ethics, I am afraid that I differ from him even more widely than I have done from Mr. Darwin.
He writes (”Genesis of Species,” p. 234): ”That 'natural selection'
could not have produced from the sensations of pleasure and pain experienced by brutes a higher degree of morality than was useful; therefore it could have produced any amount of 'beneficial habits,'
but not abhorrence of certain acts as impure and sinful.”
Possibly ”natural selection” may not be able to do much in the way of acc.u.mulating variations that do not arise; but that, according to the views supported in this volume, all that is highest and most beautiful in the soul, as well as in the body, could be, and has been, developed from beings lower than man, I do not greatly doubt.
Mr. Mivart and myself should probably differ as to what is and what is not beautiful. Thus he writes of ”the n.o.ble virtue of a Marcus Aurelius” (p. 235), than whom, for my own part, I know few respectable figures in history to whom I am less attracted. I cannot but think that Mr. Mivart has taken his estimate of this emperor at second-hand, and without reference to the writings which happily enable us to form a fair estimate of his real character.
Take the opening paragraphs of the ”Thoughts” of Marcus Aurelius, as translated by Mr. Long:-
”From the reputation and remembrance of my father [I learned] modesty and a manly character; from my mother, piety and beneficence, abstinence not only from evil deeds, but even from evil thoughts. . .
. From my great-grandfather, not to have frequented public schools, and to have had good teachers at home, and to know that on such things a man should spend liberally . . . From Diognetus . . . [I learned] to have become intimate with philosophy, . . . and to have written dialogues in my youth, and to have desired a plank bed and skin, and whatever else of the kind belongs to the Greek discipline.
. . . From Rusticus I received the impression that my character required improvement and discipline;” and so on to the end of the chapter, near which, however, it is right to say that there appears a redeeming touch, in so far as that he thanks the G.o.ds that he could not write poetry, and that he had never occupied himself about the appearance of things in the heavens.
Or, again, opening Mr. Long's translation at random I find (p. 37):-
”As physicians have always their instruments and knives ready for cases which suddenly require their skill, so do thou have principles ready for the understanding of things divine and human, and for doing everything, even the smallest, with a recollection of the bond that unites the divine and human to one another. For neither wilt thou do anything well which pertains to man without at the same time having a reference to things divine; nor the contrary.”