The Old Riddle And The Newest Answer - LightNovelsOnl.com
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So again, speaking of a certain conclusion of Professor Haeckel's concerning the embryology of lemurs, which MM. Grandidier and Alphonse Edwards afterwards proved experimentally to be altogether erroneous, de Quatref.a.ges writes:[217]
Haeckel will perhaps answer that the publication of his book preceded the observation of the French savants. But such a plea itself discloses a method of procedure which is common to the majority of evolutionists, and of which, it must be added, Darwin set the example. When confronted by a question about which n.o.body knows anything, they appeal precisely to this want of knowledge, and draw arguments from their very ignorance.
In like manner speaks the Reviewer already cited more than once.
Thus:[218]
The peculiarities of geographical distribution seem very difficult of explanation on any theory. Darwin calls in alternately winds, tides, birds, beasts, all animated nature, as the diffusers of species, and then a good many of the same agencies as impenetrable barriers.... With these facilities of hypothesis there seems to be no particular reason why many theories should not be true. However an animal may have been produced, it must have been produced somewhere, and it must either have spread very widely or not have spread, and Darwin can give good reasons for both results.
And again:[219]
We are asked to believe all these maybes happening on an enormous scale, in order that we may believe the final Darwinian "maybe" as to the origin of species. The general form of his argument is as follows:--"All these things may have been, therefore my theory is possible, and since my theory is a possible one, all those hypotheses which it requires are rendered probable." There is little direct evidence that any of these maybes actually _have been_.
In no respect, moreover, have Darwin's followers more closely imitated their master than in the construction of such hypotheses, which would appear to const.i.tute in the eyes of many the most important work of Science. Attention has very largely been diverted from Nature as actually existing, which seems to be studied more for the light it can be supposed to throw upon evolutionary history, than simply for itself, and it seems to be thought that to imagine the mode of an evolutionary process is equivalent to establis.h.i.+ng the facts which that process supposes. By this method lengthy and learned papers are written concerning the transformation of one species into another, which in reality do no more than describe in minute detail all the changes which must have taken place, _if_ the said transformation really occurred.
That Science is thus benefited, is not the opinion of some at least who are well ent.i.tled to speak on her behalf, for as the President of the Linnean Society recently observed,[220] as one grows older, it becomes more and more apparent that facts alone are of any serious interest, and that speculations however ingenious and attractive are best left to the constructive and destructive energies of the young. So too, a few years ago, the President of the Microscopical Society complained that interest in living creatures is largely supplanted by dead ones.[221]
We read much [he said] of the animal's organs: we see plates showing that its bristles have been counted, and its muscular fibres traced to the last thread; we have the structure of its tissues a.n.a.lyzed to their very elements; we have long discussions on its t.i.tle to rank with this group or that; and sometimes even disquisitions on the probable form and habits of some extremely remote, but quite hypothetical, ancestor, who is made to degrade in this way, or to advance in that, or who is credited with one organ or deprived of another, just as the ever-varying necessities of a desperate hypothesis require....
There is another aspect of the question which must by no means be overlooked. It has to be a.s.sumed that Natural Selection, or the survival of the fittest in the struggle for existence, necessarily tends to the benefit of the _race_ and moreover to its farther development on the upward grade, towards a more perfect and more specialized organization;--in Mr. Herbert Spencer's words, to progression from a relatively indefinite incoherent h.o.m.ogeneity, to a relatively definite, coherent heterogeneity. But here many questions occur.
In the first place, a consideration presents itself, which appears to furnish the most formidable of all difficulties in the way of Mr.
Darwin's hypothesis. How can this struggle for existence be supposed to have any tendency to promote organic development to ever higher and more perfect types, in the orderly sequence which has in fact occurred? The "Survival of the fittest" means only the survival _of the fittest to survive_,--of such as can find means of living where others cannot.
Unless it can be shown that increased complexity of organization necessarily brings with it such increased vitality, Natural Selection can do nothing for organic development. If the mere power of living be the only factor in the process, as on Mr. Darwin's showing it is, a man is only a more complicated and delicate machine for securing the same object which can equally well, or better, be attained by a mole, a c.o.c.kroach, or a microbe. And who will say that, so far as this particular end is concerned, he is better equipped than creatures which all the resources of civilization are powerless to exterminate?
That practical advantage in the struggle for existence must necessarily accompany increased specialization of organs, and thus produce a "higher" organization, was a prime point of Mr. Darwin's argument, though at the same time he found himself compelled to enc.u.mber it with qualifications which go very far to neutralize its force; for he had to explain the obvious fact that so many creatures which represent the lowest and least specialized forms of life, have survived down to our own time. Thus he writes:[222]
The degree of differentiation and specialization of the parts in organic beings, when arrived at maturity, is the best standard, as yet suggested, of their degree of perfection or highness. As the specialization of parts is an advantage to each being, so natural selection will tend to render the organization of each being more specialized and perfect, and in this sense higher; not but that it may leave many creatures with simple and unimproved structures fitted for simple conditions of life, and in some cases will even degrade or simplify the organization, yet leaving such degraded beings better fitted for their new walks of life.
By this fundamental test of victory in the battle of life, as well as by the standard of the specialization of organs, modern forms ought, on the theory of Natural Selection, to stand higher than ancient forms. Is this the case? A large number of palaeontologists would answer in the affirmative; and it seems that this answer must be admitted as true, though difficult of proof.
That is to say, Natural Selection is just as ready to degrade as to elevate a creature, according to the actual requirements of the circ.u.mstances in which it is placed, and how far progress has been the rule, rather than stability or retrogression, is a question for geological history to determine. This we shall have to consider in our next chapter.
It is likewise obvious that so far as the mere struggle for existence is concerned, a species each of whose individual members is but poorly furnished, may nevertheless flourish unimpaired on the mere strength of its fecundity. It is thus, says M. Blanchard,[223] that the lower forms of life continue to hold their own despite the enormous ravages to which they are subject. The herring, for example, affords food to all the fowls of the air and fish of the sea, over and above the myriads annually requisitioned by man. Yet its hosts show no sign of being exterminated or even reduced. Much the same is the case of the cod; but a tribe one individual of which has been known to produce nine million eggs does not require much in the way of coherent heterogeneity to ensure its survival.
Thus it appears that of itself Darwinism affords no explanation whatever of the regular progression of life forms from lower to higher, to which the records of Nature bear witness, and which is the one solid fact suggesting the idea of Evolution.
Such are some of the reasons which, on purely rational grounds, appear amply to justify those who decline to pledge their faith to Darwinism, in spite of the popularity it enjoys. But what is to be said of the phenomena cited as furnis.h.i.+ng positive and unimpeachable evidence in its favour, which were mentioned above in our sketch of its main features?
First as to the rudimentary, fragmentary, or vestigial organs so common in Nature. These, it is said, being of no possible advantage to their possessors, and often a serious disadvantage, can be explained only by supposing that they were serviceable in the past to the ancestral race whence these possessors are derived, and have since been superseded by other modifications of structure, so as to dwindle away by disuse. This, no doubt, seems a very plausible explanation, but it does not follow that we ought immediately to adopt it as a certainty, instead of setting ourselves to examine how it accords with all the facts. Nothing is more dangerous and less scientific than to be in a hurry to conclude that everything is certain which seems to ourselves probable, especially if it suits a theory of our own. Unfortunately, this law is too frequently more honoured in the breach than the observance. In the present instance, Professor Haeckel himself furnishes an example. He is quite sure that the rudimentary structures can have but one significance, and that they are fatal to the idea of purpose in Nature, the object of his special aversion, and so he has proposed a new term, "Dysteleology," to embody this idea, of which he says,[224]
_Dysteleology, or the theory of purposelessness_ [is] the name I have given to the science of rudimentary organs, of suppressed and degenerated, aimless and inactive, parts of the body; one of the most important and most interesting branches of comparative anatomy, which, when rightly estimated, is alone sufficient to refute the fundamental error of the teleological and dualistic conception of Nature, and to serve as the foundation of the mechanical and monistic conception of the universe.
It will be sufficient to quote Professor Huxley's remarks upon this pa.s.sage, taken from the very laudatory review he wrote of the work in which it occurs.[225]
Professor Haeckel has invented a new and convenient name, "Dysteleology," for the study of the "purposelessnesses" which are observable in living organisms--such as the mult.i.tudinous cases of rudimentary and apparently useless structures. I confess, however, that it has often appeared to me that the facts of Dysteleology cut two ways. If we are to a.s.sume, as evolutionists in general do, that useless organs atrophy, such cases as the existence of lateral rudiments of toes in the foot of a horse place us in a dilemma.
For, either these rudiments are of no use to the animal, in which case, considering that the horse has existed in its present form since the Pliocene epoch, they surely ought to have disappeared; or they are of some use to the animal, in which case they are of no use as arguments against Teleology. A similar, but stronger argument may be based upon the existence of teats, and even functional mammary glands in male mammals.... There can be little doubt that the mammary gland was as apparently useless in the remotest male mammalian ancestor of man as in living men, and yet it has not disappeared. Is it then still profitable to the male organism to retain it? Possibly; but in that case its dysteleological value is gone.
In later editions Professor Huxley further observed: "The recent discovery of the important part played by the Thyroid gland should be a warning to all speculators about useless organs."[226]
It seems, therefore, the wiser part to refrain from basing any vital conclusions upon these organs until we can a.s.sure ourselves that our knowledge warrants our so doing. As the same Professor Huxley intimated, it might be well for palaeontologists, and doubtless for biologists likewise,[227] "To learn a little more carefully that scientific '_ars artium_,' the art of saying 'I don't know.'"
So again as to the phenomena of embryology. No doubt they are very striking and impressive. That the most highly developed creatures, and man himself, should in the first stages of existence exhibit the characteristics of lower forms, is an exemplification of development no less signal than the succession of ascending types witnessed to by the rocks. It is not easy to see, however, why it should be taken for granted that this can only signify genetic descent from all such forms, and that these embryo animals are engaged in climbing up their genealogical trees. Yet this is usually a.s.sumed as a matter of course, and any one who ventures to question the validity of such an inference, must be prepared to find himself accused of dogmatizing.
And yet, after all, upon what grounds does the a.s.sumption rest? That such a recapitulation of racial experiences forms no essential feature of Evolution is sufficiently evident from the case of the vegetable world,--for plants do not climb _their_ genealogical trees, or pa.s.s in the seed through a series of botanical phases. And as to animals, since through all varieties of form, each always arrives at the required term, it is obvious that, apart from any archaic a.s.sociations, and on Darwinian principles themselves, these forms must be the best for the purpose at each respective stage,--perhaps the only ones by which the term could be reached. It is therefore, to say the least, quite conceivable, that we have here the whole explanation and need go no further.
In certain instances this obvious consideration is strikingly ill.u.s.trated. Thus the salamander, an Amphibian of the newt family, brings forth its young in adult condition without gills.[228] But previously to birth they have gills relatively large. The experiment having been tried of bringing some of them forth by artificial means before their time, and placing them in water, the first thing they did was to cast off these big gills, which were speedily replaced by new ones of much smaller size, and evidently better suited for the work required, as they lasted as long as a fortnight.
Here, in the first place, it is quite impossible to suppose that the large gills would continue to appear unless they were of advantage during the period of gestation. It is equally evident that it is not from a previous aquatic condition that they are inherited, for in such a condition they are useless. Finally, as Mr. Mivart observes, the new gills, suitable for unwonted conditions, were developed "not in a struggle for existence against rivals, but directly and spontaneously from the innate nature of the animal."
This view of the matter commended itself on mature consideration to so ardent an evolutionist as Carl Vogt, with whom we may couple M. de Quatref.a.ges, who cites his words with approval as follows:[229]
It has been laid down as a fundamental law of biogenesis that ontogeny (the development of the individual) and phylogeny (that of the race) must exactly correspond.... This law which I long held as well founded is absolutely and radically false. Attentive study of embryology shows us, in fact, that embryos have their own conditions suitable to themselves, very different from those of adults.
"In a word," M. de Quatref.a.ges continues, "the learned Genevan professor rightly considers that, 'The ontogenesis of all organic beings without exception, is the normal result of all the various influences which operate upon such beings.'"
But it must, moreover, be noted that the story which embryology can be made to tell is by no means so plain as we might easily be led to suppose.
Thus, although snakes are held to be descended from lizards, and some of them have rudimentary legs even in the adult stage, others have no trace of limbs even in the egg, while they _have_ vestiges of gills, and thus would seem to be visibly linked to ancient water-dwelling ancestors, and not to far more recent land-dwellers. Again;[230] Amphibians (frogs, newts and the like) agree in some respects, as to the development of the germ, with mammals, differing in the same respects from reptiles and birds. But reptiles and birds are supposed to be a more recent development than Amphibia, and therefore should intervene between them and mammals on the genealogical tree. Moreover the eggs of one group of Amphibians are found to exhibit some remarkable resemblances to those of reptiles and birds, from which it would thus appear to have derived them, although on other grounds it is declared to be of an older stock than theirs. Most frogs, toads, and newts come out of the egg as tadpoles, furnished with gills and so breathing in water. This should signify that these creatures are descended from fish or fishlike ancestors. But one frog (_Rana opisthodon_) is never a tadpole even in the egg, from which he gets out by means of a special opener on his snout which he has somehow acquired. On the other hand certain newts[231] breed as tadpoles instead of in their mature form, which looks like an attempt to climb down the tree instead of up.
It will be remembered that the latter phrase was that used by Professor Milnes Marshall. Yet even he expressed himself strongly concerning the exaggerations of Professor Haeckel on this subject. In his review of Haeckel's _Anthropogenie_,[232] after observing that many descriptions of human embryology have been based on observations of dogs, pigs, rabbits, or even chickens and dogfish, he thus continued regarding the book before him:
A student who relied on Professor Haeckel's description, would obtain an entirely erroneous idea of the development of the human embryo.... It is a matter for great regret that a book of 900 pages, bearing such a t.i.tle, should be allowed to appear, in which the account of the actual development of the human embryo is so inadequate or even erroneous.
Far more fundamental, however, is a remark of Mr. Mivart's, that if, as Darwinians say, the development of the individual is an epitome of that of the species, the latter must like the former be due to the action of definite innate laws unconsciously carrying out definite preordained ends and purposes. For although cells or embryos may be indistinguishable from one another, and may appear to us identical in const.i.tution, their differences are absolute. Each is determined to be one sort of animal and no other, and can live at all only on condition of developing towards the prescribed form.--Therefore, whatever evidence the embryonic forms may be supposed to afford in support of Evolution, they have nothing in common with the haphazard process of Natural Selection.
And here again Professor Huxley found himself obliged to enter his _caveat_, and to intimate his opinion that some of his friends were inclined to build too confidently upon this foundation. As his biographer Professor Weldon writes in the _Dictionary of National Biography_:
Darwin had suggested an interpretation of the facts of embryology which led to the hope that a fuller knowledge of development might reveal the history of all the great groups of animals at least in its main outlines. This hope was of service as a stimulus to research, but the attempt to interpret the phenomena observed led to speculations which were often fanciful and always incapable of verification. Huxley was keenly sensible of the danger attending the use of a hypothetical explanation, leading to conclusions which cannot be experimentally tested, and he carefully avoided it.... In the preface to the _Manual of the Comparative Anatomy of Invertebrated Animals_, he says: "I have abstained from discussing questions of aetiology,[233] not because I underestimate their importance, or am insensible to the interest of the great problem of Evolution, but because, to my mind, the growing tendency to mix up aetiological speculations with morphological generalizations will, if unchecked, throw Biology into confusion."
Accordingly, Huxley himself based his faith in Evolution on palaeontological evidence, and attempted to decide the precise course it had followed only "in the few cases where the evidence seemed to him sufficiently complete." This line of enquiry we have still to pursue, but meanwhile, it is evident that the phenomena we have been considering, failing to meet the approval of so thorough-going an Evolutionist as he undoubtedly was, cannot be said to furnish convincing scientific evidence in favour of Darwinism.
It will be asked how it comes to pa.s.s, if the Darwinian system really lies open to so many objections, that it occupies so large a place in scientific estimation. To this we must reply that, in spite of its great name, its success has throughout been popular rather than truly scientific, and that as time went on it has lost ground among the cla.s.s of men best qualified to judge. Evolutionists there are in plenty,--but very few genuine Darwinists, and amongst these can by no means be reckoned all who adopt the t.i.tle, for not a few of them--as Romanes and Weismann--profess doctrines which cannot be reconciled with those of Darwin himself. Meanwhile, an increasing volume of scientific opinion sets definitely against Darwinism as an adequate explanation of the philosophy of life, and falls into the view expressed long ago by Charles Robin[234] who, as a freethinker, had no antecedent objections against it, "Darwinism is a fiction, a poetical acc.u.mulation of probabilities without proof, and of attractive explanations without demonstration."
It would be tedious to cite testimonies at length, but, in addition to M. de Quatref.a.ges who has made a full and careful study of the whole question, [_Charles Darwin et ses precurseurs Francais_, and _Les Emules de Darwin_] may be mentioned such continental scholars as Blanchard [_La vie des etres animes_], Wigand [_Der Darwinismus und die Naturforschung_, etc.], Wolff [_Beitrage zur Kritik der darwinschen Lehre_], Hamann [_Entwicklungslehre und Darwinismus_], Pauly [_Wahres und Falsches an Darwins Lehre_], Driesch [_Biologisches Zentralblatt_, 1896 and 1902], Plate [_Bedeutung und Tragweite des Darwinschen Selektionsprincip_], Hertwig [_Address to Naturalist Congress_, _Aachen_, 1900], Heer [_Urwelt der Schweiz_], Kolliker [_Ueber die darwin'sche Schopfungstheorie_], Eimer [_Entstehung der Arten_], Von Hartmann [_Wahrheit und Irrthum im Darwinismus_], Schilde [_Antidarwinistisches im Ausland_], Du Bois-Reymond [_Conference_, August 2, 1881, etc.], Virchow [_Freiheit der Wissenschaft_, etc.], Nageli [_Mechanisch-physiologische Theorie der Abstammungslehre_], Schaafhausen [_Ueber die anthropologischen Fragen_], Fechner [_Ideen zur Schopfungs-und Entwicklungsgeschichte der Organismen_], Jakob [_Der Mensch_, etc.], Diebolder [_Darwins Grundprinzip_, etc.], Huber [_Die Lehre Darwins kritisch betrachtet_], Joseph Ranke, and Von Bauer,--all of whom either reject Darwinism altogether, or admit it only with fatal reservations.
Special weight must attach to the adverse verdict of M. Fabre, styled by Darwin himself "that inimitable observer," who declares that he cannot reconcile the theory with the facts he encounters.[235]
It must be sufficient to quote one or two of our own countrymen, whose utterances will enable us to form an opinion as to the true scientific status of the doctrine.
We may begin with Huxley, the great popular champion of Darwinism, who did more than any other man to spread the new doctrine. Yet, strange to say, he seems never to have really accepted its fundamental tenet himself, always appearing very shy of Natural Selection, and carefully abstaining from committing himself to any responsibility for it. Thus in his treatise on _Man's Place in Nature_, he thus explains his position in its regard:
Mr. Darwin's hypothesis is not, so far as I am aware, inconsistent with any biological fact; on the contrary, if admitted, the facts of Development, of Comparative Anatomy, of Geographical Distribution, and of Palaeontology, become connected together, and exhibit a meaning such as they never possessed before; and I, for one, am firmly convinced, that if not precisely true, that hypothesis is as near an approximation to the truth as, for example, the Copernican hypothesis was to the true theory of the planetary motions. But for all this, our acceptance of the Darwinian hypothesis must be provisional so long as one link in the chain of evidence is wanting; and so long as all the animals and plants certainly produced by selective breeding from a common stock are fertile with one another, the link will be wanting. For, so long, selective breeding will not be proved to be competent to do all that is required of it to produce natural species.
This missing link, like various others, has never been supplied, and in consequence Professor Huxley never abandoned his att.i.tude of reserve. On the contrary, when, in 1880, he delivered an address to celebrate "the Coming of Age of the _Origin of Species_" he discharged the task without once mentioning Natural Selection, which is to that work as the Prince of Denmark is to _Hamlet_.
But there is one pa.s.sage in the said address, which deserves to be specially remembered:
History warns us that it is the customary fate of new truths to begin as heresies and to end as superst.i.tions; and, as matters now stand, it is hardly rash to antic.i.p.ate that, in another twenty years, the new generation, educated under the influences of the present day, will be in danger of accepting the main doctrines of the _Origin of Species_, with as little reflection, and it may be with as little justification, as so many of our contemporaries, twenty years ago, rejected them.