THE FACTS OF EVOLUTION
LEAVING the field of speculation and "ætiology," we have now to enquire, not to what causes organic Evolution may be attributable, but how far it can be shewn to have actually occurred. This can be learnt only from the history of life upon earth as disclosed by the evidence of palæontology, or the geological record, and we are thus brought to the investigation of that evidence, by which alone, as Professor Huxley agrees, can the truth about Evolution be scientifically or satisfactorily established. In his address recently mentioned on occasion of the twenty-first birthday of the Origin of Species, having spoken of various advances of our knowledge, as in comparative anatomy and embryology, which had helped to win acceptance for transformist doctrines, he thus continued:
But all this remains mere secondary evidence. It may remove dissent, but it does not compel assent. Primary and direct evidence in favour of evolution can be furnished only by palæontology. The geological record, so soon as it approaches completeness, must, when properly questioned, yield either an affirmative[{205}] or a negative answer; if evolution has taken place, there will its mark be left; if it has not taken place, there will be its refutation.
This is common sense. Evolution can claim to be a scientific truth, only so far as clear evidence is forthcoming that Evolution there has been. If the geological record be sufficiently complete to prove or disprove its claims, the question is settled for ever. If, on the other hand, the record be not complete enough for a conclusive verdict, it is, at least, hard to understand the grounds of such a statement as that the doctrine of Evolution has long since passed beyond the stage of discussion among scientific thinkers;[241] or that of Professor Marsh, that to doubt Evolution is to doubt Science; or of Professor Huxley himself[242]—"So far as the animal world is concerned, Evolution is no longer a speculation, but a matter of historical fact."
This historical enquiry is accordingly all-important, and it is one which should be easy to undertake without any prepossessions, for it is hard to see upon what à priori grounds these could rest. That there has been Evolution in one sense of the term is obvious,—that is to say, development of organic types from lower to higher forms, from the sea-weed or fungus to the oak or the rose, from the star-fish or the coral-insect, to the eagle or to man. The question is, not whether there has been such a[{206}] progressive succession of forms, but whether one form has proceeded from another genetically, being produced in the same manner as individuals of a species now are. That this has been the case, as Professor Huxley tells us in the same address, is the cornerstone of evolutionary teaching. He appears indeed to restrict Evolution within the limits of classes and groups, but such restriction is so contrary to all his principles that the words which seem to imply it can scarcely be taken as having any definite significance. Should the appearance of different classes and groups require to be severally accounted for, we should be landed back in the system of separate creations against which he is never tired of inveighing.
The fundamental doctrine of all forms of the theory of evolution applied to biology [he says] is that the innumerable species, genera, and families of organic beings with which the world is peopled have all descended, each within its own class or group, from common parents, and have all been modified in the course of descent.
And, holding as he does that palæontology furnishes the necessary evidence, he thus continues:
And, in the view of the facts of geology, it follows that all living animals and plants are the lineal descendants of those which lived long before the Silurian epoch.
Here is a plain issue, and one, as has been said, to be discussed without prejudice. That the innumerable[{207}] forms of organic life should thus have been genetically derived one from another, is no more difficult to conceive than that they should have come into existence at all. Moreover, it appears to our minds almost a first principle that natural law must suffice to account for the phenomena of nature from beginning to end, and that any system is self-condemned which finds anywhere in these phenomena evidence of a non-natural, or supernatural, interposition. Has not such a theologian as Suarez, following St. Augustine, laid it down as an axiom[243] that God does not directly interfere with the operations of Nature, when He can effect His purposes through natural causes? Undoubtedly, too, it is difficult for our minds to imagine in what way, except through genetic evolution, the successive production of more and more developed types could be effected.
But, as has before been observed, what seems to us probable is not therefore proved to be true. What we want are facts, and by facts we must be ready to abide. At the same time, it is not very easy to understand the supreme importance which evolutionists generally appear to attach to the descent of all living creatures from some one original, and their abhorrence of the idea that the power, whatever it was, which first produced life, may have operated repeatedly, at different epochs, to repeat the production. It seems to be assumed that this must imply "miracle"[{208}] and interruption of the continuity of Nature, to admit which is irrational and unscientific. But since life did unquestionably once originate somehow, which Science makes no attempt to deny, why should it be so improper to suppose that it originated more than once, at various times and in various forms, and that, consequently, genetic descent with modification, or "Evolution," is not the explanation of typic development? As Sir J. W. Dawson writes[244] concerning the oyster tribe, whereof two species are found in the Coal Measures (one European and the other American), and a continuous succession of species ever since:
All these species may have proceeded from one origin, by descent with modification, or, on the other hand, the same causes which led to their origination in the Carboniferous may have operated again and again.
It must, however, be remembered that, if the theory of genetic descent with accumulation of minute modifications be the true explanation of the production of new forms, it necessarily follows, that could a complete record be forthcoming of the ancestry of any actual species, there would be found in that pedigree no distinction of species or genera, for no sharply marked lines of limitation would be discoverable. It would be like the case of a man who had been photographed every hour of his life from birth to old age;—immense though the difference[{209}] might be between the two extremes, the gradations of change would at all points pass as imperceptibly into one another as do the phases of the moon. This consideration is both fundamental and obvious, yet it would seem to be almost universally ignored. It appears to be thought that, in order to demonstrate the fact of evolution, all that is needed is to find a form here and there, in some sense intermediate between others,—like the reptilian birds already mentioned. This would imply that the course of Evolution must be like that of an army, making long marches from point to point, and traceable only by the remains of its camp-fires: whereas it should be as that of a glacier continuously creeping on, and leaving its tracks at one point as much as another. What are wanted, therefore, as evidence for Evolution, are not isolated specific forms uniting some characteristics of those which they are supposed to connect,—as Nelson's men-of-war form a stepping-stone between the vessels of the Norsemen and the ironclads of the present day,—but a series sufficient to show, or at least to indicate, that all changes have been gradual and insensible, without the introduction at any point of a new element. To pursue the illustration, such a new element would be gunpowder or steam in the evolution of the battle-ship, for by no mere development could bows or javelins produce a cannon, or sailing ships a steamboat.
Therefore, in proportion as the geological record approaches completeness, its testimony,—if it is[{210}] to be in favour of Evolution—must tend more and more in this direction, and unless, in some instance at least, clear evidence be discoverable of the melting of one form into another, it cannot possibly be said that we have sufficient proof that such a process ever occurred. Mere graduated resemblance of isolated forms does not necessarily imply such transmutation, as we see for example in the methodical progression of shape, exhibited by various crystals, and even more remarkably in the affinities which we can recognize among what we know as elementary substances.
There is another important point to be borne in mind. According to the teaching of Evolutionists such as Darwin or Haeckel,[245] every Species has originated from a single ancestor,—or, as they should rather say, from a single pair.
If this were so, it would necessarily follow that every new form, originating in some particular spot of earth, would very gradually spread thence to other regions, fighting its way along. As Mr. Darwin acknowledges,[246] "The development by this[{211}] means (i.e. Natural Selection) of a group of forms, all of which are descended from some one progenitor, must have been an extremely slow process; and the progenitors must have lived long before their modified descendants."
Of this gradual spread of new types there should, at least in some cases, be some palæontological evidence.
It is likewise by no means easy to understand how species thus generated could stand solitary and isolated from kindred forms in the records of the earth. The pair of individuals which started a new persistent group,—its members all stamped with the same specific characters, while all around were in a state of flux and divergence,—differed from their immediate ancestors, as we have seen, only infinitesimally. They can have differed no more from many of their contemporaries, for all the lines of descent must ramify afresh in each generation, and so form a web rather than anything like a line. It is not very easy to understand how a pair here and there struck root and founded a species, while the thousands which jostled them round about failed to do so, for the others which survived longest must be supposed to have resembled them most nearly, and therefore to have participated in their advantages. At least, we should expect to find around them the débris of the multitude they vanquished in the struggle for existence.
We are told, moreover, that, with hardly an exception, the organic forms found in a fossil state[{212}] must be supposed to be the last of their special line of development, which terminated in them; so that neither can they be claimed as the direct ancestors of any other forms, fossil or living, nor can any others which are actually known be claimed as their progenitors. The genealogies supplied for almost all known species, extinct or existing, are admittedly conjectural, and as in the most famous instance of all, namely the supposed common ancestor of simians and men, the links are persistently "missing." Thus M. de Quatrefages, speaking of the human pedigree as set forth by Professor Haeckel, writes thus:[247]
All species, existing or extinct, are said to have been preceded by ancestral forms which have disappeared without leaving the slightest vestige behind them. The amphioxus itself, which more than any other realizes the type of the group it represents, was preceded, according to Haeckel, by the provertebrate, which no man has ever seen, but of which, nevertheless, the Jena professor gives us a figure, and describes the anatomy.
Thus the number of forms postulated by the theory of genetic Evolution, must have been enormous beyond conception, in comparison with those belonging to the numerically insignificant groups which formed the mere extremities of branches on the genealogical tree.[{213}]
This being premised, we must ask what Geology has to tell us on the subject, and it will be well to begin by briefly recalling the main features of the geological record.
The stratified rocks comprising the crust of the earth, in which fossil plants and animals are found embedded, have evidently been formed at successive periods, chiefly by the agency of water, each formation having begun as a sediment like the mud or ooze at the bottom of our oceans and seas. Geological investigation has proved that the chronological order of the strata thus deposited can be satisfactorily determined, and they are found to divide themselves, in respect of the organisms they contain, into three great series, lying above the Azoic (or lifeless) rocks, older than them all.
These series, beginning from the bottom, in which order we shall have to trace their history, are most conveniently named Primary, Secondary, and Tertiary, otherwise termed respectively, Palœozoic ("ancient life"), Mesozoic ("middle life"), and Kainozoic ("recent life"). Each of these again, contains various formations, or as we may call them volumes of its chronicle, each of which has its fixed place in order of sequence.
Thus, always proceeding from below upwards, in the Primary series, commencing with the Laurentian, we find successively the Huronian, Cambrian, Silurian, Devonian or Old Red Sandstone, Carboniferous, and Permian.[{214}]
In the Secondary, the lowest formation is the Triassic or New Red Sandstone, followed by the Jurassic or Oolite, and the Cretaceous or Chalk.
Finally the Tertiary has three main divisions; the Eocene, or "dawn of the recent," Miocene, or "less recent," and Pliocene, or "more recent."
Above these comes the series now in progress, variously called, Quaternary, Post-Tertiary, and Pleistocene, or "most recent."
It seems advisable to begin our investigation with the vegetable kingdom, as its classification being comparatively simple, the essential points of its development are easily followed. We cannot do better than start with the summary of its main divisions furnished by Mr. Carruthers.[248]
The vegetable kingdom is divided into sections, according to the simplicity or complexity of structure. Associated with plants of simple structure we find, as a rule, more elementary organs of reproduction. Linnaeus made two great divisions, of flowering (Phanerogams) and flowerless plants (Cryptogams).... The higher group have flowers, with their stamens and pistils, which produce seeds, while the lower group are without flowers and bear spores, which are much simpler bodies than seeds. There are seven main groups of spore-bearers—the algæ or water-weeds; the fungi or mushroom family; the lichens, which cover old walls and rocks with patches of coloured vegetation; the mosses with their green leaves and urn-shaped fruit; the ferns with[{215}] their large and usually much-divided leaves, on the back or edges of which the spores are borne; the horsetails, found in wet places, having jointed hollow stems and spores produced in little cones; and the club-mosses, upright or creeping leafy plants found on our mountains. These seven groups may be arranged in two divisions, according to the tissues of which they are formed. In the first four the whole plant is composed of cells, while in the last three a firm vascular skeleton is present. These characters are of great importance to the student of fossil plants.... The flowering plants are more complex in their structure, and in their organs of reproduction. The lowest group of these plants is the Gymnosperms, or naked-seeded plants, like our yews and pines. The other flowering plants (Angiosperms) have their seeds in a closed fruit. These are divided into two sections from characters derived from the embryo plant in the seed, depending on whether this minute plant has one seed-leaf (cotyledon) or two, and so we have Monocotyledons and Dicotyledons. The higher group, or dicotyledons, have been arranged into three divisions, according to the complexity of the flower. In one large group (Apetalae) the pistil and stamens are not surrounded by petals, e.g. in the oak and the stinging nettle: superior to them are the plants (Monopetalae) in which the petals form a cup, as the blue-bell[249] and the gentian, while the highest group (Polypetalae) have all the petals separate, as the buttercups and roses.[250]
It is most important to recollect that on evolutionary principles the first representatives of any such classes—and the same holds of animals as well—must have been generalized forms, representing the type in the rough, or, in Mr. Herbert Spencer's phrase, exhibiting by comparison with their successors indefinite incoherent homogeneity, as contrasted with definite coherent heterogeneity. They should bear the same sort of relation to the finished articles worked up by Evolution as did the first bone-shaker bicycle to our latest patterns, or the news-sheets of Cromwell's time to the Times or Graphic of to-day. On this, as we saw in the last chapter, Mr. Darwin strongly insists, confessing at the same time that the Geological record alone can establish such progress as a fact.
How these various classes of plants appear actually to have come upon the scene, Mr. Carruthers relates both in the paper from which we have just quoted, and at greater length in the address which he delivered as President of the Geologists' Association,[251] to the following effect.
In the first place, he declares that although the geological record, at least as known to us, is very imperfect, and represents only an insignificant fragment of plant-history,
There is a large series of plant-remains completely[{217}] and accurately known which supply a fair representation of the great events of plant-life that have taken place on the earth since Palæozoic times. And these are more than sufficient to establish or destroy this hypothesis [of genetic evolution] by their testimony.
There is—he goes on to say—indirect evidence of the existence of vegetable life, long before we find any actual remains. Such indirect evidence is afforded in the first place by the abundance during this period of animal life, needing plants for its sustenance, and secondly by the enormous quantity of carbon in the rocks, which must have been secreted from the atmosphere by vegetable tissues. There are also certain surface marks or impressions occasionally to be found, which are probably due to plants of a soft and perishable character like the cellular cryptogams, and which although extremely vague and undefined, at least do not contradict the evolutionist, who regards them as evidence that the Algæ were, as according to him they ought to have been, the primeval plants. Mr. Carruthers adds a caution however, which can find its application in other instances as well:
While making this admission in relation to the vegetation of these older rocks, I must protest against the practice of completing the record of life forms, by filling in particular groups without any authority except the writer's impression of an adopted hypothesis, and then basing arguments on these assumptions in support of the hypothesis which created them. So completely has
phylogenetic [or racial] evolution become the creed of some leading naturalists that they unwittingly proceed in this manifestly unphilosophical method. But it is a first axiom, though one often forgotten, in this as in every scientific enquiry, that no step can be made in advance which is not based on fact.
After this initial stage, the story becomes much clearer, and at the same time less easy to reconcile with evolutionary requirements.
Instead of making their appearance singly and successively, and passing imperceptibly one into another, all three groups of Vascular Cryptogams, and the Gymnosperms into the bargain, come on the stage together, in the Devonian strata; and Monocotyledons in the lower Carboniferous immediately following. There is no trace whatever of the development of any of these forms from the earlier cellular cryptogams:
But [says Mr. Carruthers] the evolution of the Vascular Cryptogams, and the Phanerogams, from the green seaweeds, through the liverworts and mosses, if it took place, must have been carried on through a long succession of ages, and by an innumerable series of advancing steps; and yet we find not a single trace either of the early water forms or of the later and still more numerous dry-land forms. The conditions that permitted the preservation of the fucoids in the Llandovery rocks at Malvern, and of similar cellular organisms elsewhere, were, at least, fitted to preserve some record of the necessarily rich floras, if they existed, which through[{220}] immense ages, led by minute steps to the Conifer [Gymnosperm] and Monocotyledon of these Palæozoic Rocks.
Further, these earliest plants are not generalized forms of the various tribes to which they belong, but they are as highly specialized as any subsequent representatives of the particular group to which they belong, and wherever they differ from later plants, it is in the possession of a more perfect organization.
From all which facts Mr. Carruthers thus argues:
The complete absence of intermediate forms, and the sudden and contemporaneous appearance of highly organized and widely separated groups, deprive the hypothesis of genetic evolution of any countenance from the plant-record of these ancient rocks. The whole evidence is against evolution, and there is none for it.[252]
Dicotyledons furnish evidence of especial value. On account of their higher organization, they are easily distinguished from both Monocotyledons and Gymnosperms; and they present features which clearly differentiate them amongst themselves. They did not make their entry till after a long interval—and their remains are therefore to be found in strata comparatively recent and better known to us than those of the older rocks. It is in the Chalk, the newest of the Secondary or Mesozoic formations, that they first exhibit themselves, and they do it in the same fashion as their predecessors.[{221}]
When the Dicotyledons appear in the upper cretaceous beds, representatives of the three great groups [Apetalæ, Monopetalæ, Polypetalæ] appear together in the same deposit. Moreover, these divisions are represented, not by generalized types, but by differentiated forms, which, during the intervening epochs, have not developed even into higher generic groups.
And, here again, there is no vestige of intermediate species, linking dicotyledonous plants with other types.
No trace of a plant belonging to this great division has yet been detected in any earlier stratum [than the upper chalk]. There is no evidence whatever for Haeckel's statement that the Apetalæ probably existed in the Triassic and Jurassic periods.... It cannot be doubted that the conditions favourable to the preservation of Monocotyledons and Equisetums would have secured the preservation of some of the Apetalæ, had they existed. This absence can be accounted for only on the supposition that they formed no part of the then existing vegetation. And in the deposits older than the Trias, or in any subsequent deposits, no intermediate form has been detected,—no Gymnosperm or Monocotyledon which exhibits in any point of its structure a modification towards the more highly organized Dicotyledon.
Nor, on the same authority, is this all.
It is equally important in its bearing on the hypothesis of genetic evolution that the generic groups above named[{222}] have persisted from the first known appearance of Dicotyledons, throughout the whole of the intervening ages, and still hold their places unchanged among the existing forms of vegetation. The persistence of generic and specific types, and the certain knowledge we possess of the life of many existing species of Phanerogams and Cryptogams which have come down through the Glacial Epoch, have not been sufficiently considered in their bearing on the hypothesis.
We have already seen something of an example which illustrates this point in a remarkable manner,—that of Salix polaris, the willow which has so obstinately preserved its specific identity amid great stress of circumstances. It belongs to a very variable genus—one in which if anywhere evidence of genetic development might be looked for. Yet it is found that since a period prior to the great Ice Age, or Glacial epoch, it has remained absolutely unchanged. At such a rate, we cannot but ask, how long would Evolution take to get back to the generalized type-form, or common ancestor, of the genus Salix, and then to that of the Order Salicineae, which includes poplars as well as willows. "The Ordinal form, if it ever existed, must necessarily be much older than the period of the upper Cretaceous rocks, that is than the period to which the earliest known Dicotyledons belong."
And it is obvious that when we had got back to the parental stock of the willow tribe, we should still, as evolutionists, be separated by a gulf still vastly greater from the common ancestor of all[{223}] Dicotyledons, of oaks, apple-trees, primroses, and daisies no less than of willows and poplars.
The significance of all these various facts is thus summed up:
The whole evidence supplied by fossil plants is, then, opposed to the hypothesis of genetic evolution, and especially the sudden and simultaneous appearance of the most highly organized plants at particular stages in the past history of the globe, and the entire absence amongst fossil plants of any forms intermediate between existing classes or families. The facts of palæontological botany are opposed to Evolution, but they testify to Development, to progression from lower to higher types. The cellular Algæ preceded the Vascular Cryptogams and the Gymnosperms of the Newer Palæozoic rocks, and these were speedily followed by Monocotyledons, and, at a much later period, by Dicotyledons. But the earliest representatives of these various sections of the vegetable kingdom were not generalized forms, but as highly organized as recent forms, and in many cases more highly organized: and the divisions were as clearly bounded in their essential characters, and as decidedly separated from each other as they are at the present day.
So much for the vegetable world. As for the animal, although the number and complexity of its divisions makes it less easy to present so complete a sketch in these moderate limits, the features of its history are very similar. As Sir J. W. Dawson recounts it:[253][{224}]
In the Cambrian age, we obtain a vast and varied accession of living things, which appear at once, as if by a sudden and simultaneous production of many kinds of animals. Here we find evidence that the sea swarmed with creatures near akin to those which still inhabit it, and nearly as varied.... Had we been able to drop our dredge into the Cambrian or Silurian ocean, we should have brought up representatives of all the leading types of invertebrate life that exist in the modern seas—different, it is true, in details of structure from those now existing, but constructed on the same principles, and filling the same places in nature.
In the latter half of the Palæozoic we find a number of higher forms breaking upon us with the same apparent suddenness as in the case of the early Cambrian animals. Fishes appear, and soon abound in a great variety of species, representing types of no mean rank, but, singularly enough, belonging in many cases to groups now very rare; while the commoner tribes of modern fish do not appear. On the land, Batrachian Reptiles now abound, some of them very high in the sub-class to which they belong. Scorpions, spiders, insects, and millipedes appear as well as land-snails: and this not in one locality only, but over the whole northern hemisphere.... Nor do they show any signs of an unformed or imperfect state.... The compound eyes and filmy wings of insects, the teeth, bones, and scales of batrachians and fishes; all are as perfectly finished, and many quite as complex and elegant, as the animals of the present day.
This wonderful Palæozoic age was, however, but a temporary state of the earth. It passed away, and was[{226}] replaced by the Mesozoic, emphatically the age of Reptiles, when animals of that type attained to colossal magnitude, to variety of function and structure, to diversity of habitat in sea and on land, altogether unexampled in their degraded descendants of modern times.... Strangely enough, with these reptilian lords appeared a few small and lowly mammals, forerunners of the coming age.[254] Birds also made their appearance.
The Kainozoic, or Tertiary, is the age of Mammals and of Man. In it the great reptilian tyrants of the Mesozoic disappear, and are replaced on land and sea by mammals or beasts of the same orders with those now living, though differing as to genera and species. So greatly indeed did mammalian life abound in this period that in the middle part of the Tertiary most of the leading groups were represented by more numerous species than at present, while many types then existing[{227}]
have now no representatives. At the close of this great and wonderful procession of living beings comes Man himself—the last and crowning triumph of creation the head, thus far, of life on the earth.
DIAGRAM ILLUSTRATING THE PROGRESS OF ORGANIC DEVELOPMENT. In the above Diagram the progress of Organic Development, as manifested in higher and higher types, is indicated by the increasing divergence of new forms from primitive simplicity of structure, represented by the medium line separating the vegetable and animal kingdoms. The Supposed line of continuous Evolution, indicates the gradual course which should be taken by Development, on Darwinian or Spencerian principles, by accumulation of minute differences in successive generations, as contrasted with the abrupt and simultaneous appearance of highly differentiated types, as spoken of by palæontologists. [To face page 227.]
It must be sufficient to quote one other remark:[255]
There is no direct evidence that in the course of geological time one species has been gradually or suddenly changed into another.... On the other hand, we constantly find species replaced by others entirely new, and this without any transition. The two classes of facts are essentially different, though often confounded by evolutionists; and though it is possible to point out in the newer geological formations some genera and species allied to others which have preceded them, and to suppose that the later forms proceeded from the earlier, still, as the connecting links cannot be found, this is mere supposition, not scientific certainty. Further, it proceeds on the principle of arbitrary choice of certain forms out of many, without any evidence of genetic connexion.
Having given a tabular view of Geological periods and Life-epochs, similar to those presented above, our author remarks:[256]
If in the table above we were to represent diagrammatically the development of animals and plants, this would appear not as a smooth and continuous stream, but as a series of great waves, each rising abruptly, and then descending and flowing on at a lower level along with the remains of those preceding it.
And here may be noticed an observation made amongst others by the Comte de Saporta[257] on the remarkable parallelism of Animal and Vegetable development. After a period in which these kingdoms were respectively represented by aquatic Algæ and Protozoa, land animals and land plants appear to have come in much at the same epoch; and afterwards dicotyledonous plants immediately preceded the advent of mammals.
Mr. Mivart is of like mind with the others we have heard. "The mass of palæontological evidence," he writes,[258] "is indeed overwhelmingly against minute and gradual modification." He points out, with the North British Reviewer so frequently quoted, that had the later forms of life descended from the earlier, through such a series of imperceptible gradations as is imagined, the probability would be that no two fossil specimens would be exactly alike, whereas in fact numbers are found of certain particular patterns, and none whatever between them, fossil animals and plants falling naturally into species, genera, families, and other categories just like those of the present day.
It is this total absence of graduated series, linking different forms together, that is the great and fundamental difficulty in the way of genetic evolution. Yet this seems very seldom to be realized, and it seems constantly to be assumed that in order to establish the genetic continuity of two creatures[{229}] no more is required than to discover another standing more or less between them. Thus in the most famous of all instances, how often do we hear of "the missing link" between man and ape,—as though should a generalized form be disclosed, which might be considered a common ancestor, the question of man's simian origin would be finally settled. In the same way, as we have seen, the existence of birds with reptilian features, is taken by some as conclusive proof that birds and reptiles have descended from one stock. But what is most imperatively wanted, is persistently wanting,—namely some evidence of a series in which one form passes to another, as in a dissolving view. And yet, genetic evolutionists must suppose such series to have been the universal rule throughout the whole course of life on earth.
Assuredly [writes M. de Quatrefages][259] is it not singularly unfortunate for the evolutionary theory that so many facts which tell against it should have been preserved in the scraps of Nature's great book which remain to us, and that invariably those which would have told in its favour were recorded in lost volumes and missing leaves?
In some particular instances the absence of any trace of intermediate forms is especially significant. The tribe of Bats, for instance, is a very singular one. The wings, in which form the fore-limbs are specialized, represent the same elements as our own[{230}] hands; and other modifications of the same members have produced the paws of cats and dogs, the hoofs of horses and cattle, and the flippers of whales and porpoises,—to mention no others. What countless hosts of the Bat's ancestors must have lived and died while by accumulation of minute differences the primitive generalized limb whence all these diverse forms originated, was being turned into a wing capable of flight. Yet of all these no vestige is to be discovered. "Whenever the remains of bats have been found," says Mr. Mivart,[260] "they have presented the exact type of existing forms." The same, he tells us, holds good of other flying creatures—birds and pterodactyles—(or flying lizards—now wholly extinct). No trace of any of these is forthcoming while their wings were in the making. "Yet had such a slow mode of origin as Darwinians [and genetic evolutionists generally] contend for, operated exclusively in all cases, it is absolutely incredible that bats, birds, and pterodactyles should have left the remains they have, and yet not a single relic be preserved in any one instance of any of these different forms of wing in their incipient and relatively imperfect functional condition!"
There are other creatures which stand in solitary isolation, with no fragments of a bridge to connect them with the general body. Such is the rattlesnake's family, whose pedigree, Mr. Mivart declares,[261] we cannot even imagine—"The ancestors[{231}] of the rattlesnake are beyond our mental vision."
But the number of forms [says the same author][262] represented by many individuals, yet by no transitional ones, is so great that only two or three can be selected as examples. Thus those remarkable fossil reptiles, the Icthyosauria and Plesiosauria, extended, through the secondary period, probably over the greater part of the globe. Yet no single transitional form has yet been met with in spite of the multitudinous individuals preserved. Again, with their modern representatives the Cetacea, one or two aberrant forms alone have been found, but no series of transitional ones indicating minutely the line of descent. This group, the whales, is a very marked one, and it is curious, on Darwinian principles, that so few instances tending to indicate its mode of origin should have presented themselves. Here, as in the bats, we might surely expect that some relics of unquestionably incipient stages of its development would have been left.
Professor W. C. Williamson likewise remarks[263] on these lacunæ which persistently occur at crucial points:
If [he writes] these generic types [of plants] first came before us in such clearly defined forms, when and where did the transitional states make their appearance? The extreme evolutionists constantly affirm of those[{232}] who believe in special creation that they "habitually suppose the origination to occur in some region remote from human observation," and that "the conception survives only in connexion with imagined places where the order of organic phenomena is unknown." It is legitimate to retort upon them that they as habitually resort to "strata now covered by the sea"—to rocks "from which all traces of such fossils as they probably included have been obliterated by igneous action," and to mysterious "migrations from pre-existing continents to continents that were step by step emerging from the ocean." Unfortunately, so far as the vegetable kingdom is concerned, we have as yet failed to discover any traces of these mysterious strata or hypothetical continents in which the transitions from one plant-type to another were being brought about. The believers in special creations are not the only reasoners who have made free use of hypothetical possibilities.
He presently adds:
We have no evidence that unaided Nature has produced a single new type during the historic period. We can only conclude that the wonderful outburst of genetic activity which characterized the Tertiary age was due to some unknown factor, which then operated with an energy to which the earth was a stranger, both previously and subsequently. The knowledge of this factor is what we need in order to perfect our philosophy; and until we obtain that knowledge, many things must remain unaccounted for, so far as primeval vegetation is concerned.
And elsewhere Professor Williamson reiterates the same idea:[264]
I contend stoutly [he says] that, however numerous may be the facts that sustain the doctrine of evolution (and I am prepared to admit that there are many that do so in a remarkable manner), this unexplained outburst of new life demands the recognition of some factor not hitherto admitted into the calculations of the evolutionist school.
In the record of fossil fishes he finds some features which are particularly hard to harmonize with any theory of genetic evolution.[265] Amongst the very earliest representatives of this class, even in the upper Silurian, are found remains of sharks, in his opinion the highest order of fish, and in the Devonian and Carboniferous above, of Ganoids armour clad, like the sturgeon. But nowhere below the Chalk do we find a single scale of Cycloids or Ctenoids, which in regard alike of the scales themselves, of the nervous system and of the reproductive organs, are much below the sharks, and not above the Ganoids. To complicate matters still more, however, the skeleton of Cycloids and Ctenoids is more highly organized than that of the others, and it is thus equally impossible to describe them as progressive or as retrogressive types.[266]
Over and above this absence of intermediate or link forms, the witnesses who have been cited insist[{234}] on the fact that those earliest found are not simple or generalized representatives of their respective types, as the theory of genetic evolution requires them to be, but are as perfectly finished and specialized as those appearing in later ages. To their testimony on this point may be added that of Professor Huxley, who while frankly confessing that he would be glad enough to find evidence in favour of such progressive modification, was constrained by his love of scientific truth to bear witness as follows:[267]
The only safe and unquestionable testimony we can procure—positive evidence—fails to demonstrate any sort of progressive modification towards a less embryonic, or less generalized type, in a great many groups of animals of long-continued geological existence. In these groups there is abundant evidence of variation—none of what is generally understood as progression; and if the known geological record is to be regarded as even any considerable fragment of the whole, it is inconceivable that any theory of a necessarily progressive development can stand, for the numerous orders and families cited afford no trace of such a process.
So again he declared at a later period[268] summarizing what he had said previously:
In answer to the question, What does an impartial survey of the positively ascertained truths of palæontology[{235}] testify in relation to the common doctrines of progressive modification?... I reply: It negatives these doctrines; for it either shows us no evidence of such modification, or demonstrates such modification as has occurred to have been very slight; and as to the nature of that modification, it yields no evidence whatsoever that the earliest members of a long-existing group were more generalized in structure than the later ones.
He went on, however, to say, on this latter occasion, that discoveries made in the interval afforded much ground for softening "the Brutus-like severity" which eight years before he had exhibited in this regard, by disclosing such evidence as he had declared to be lacking. From the samples, however, which he produced, it does not appear that this fresh testimony comes to very much; and in view of the observations with which he accompanied the exposition, it would seem that in only one instance did it appear to himself thoroughly satisfactory.
Every fossil [he said][269] which takes an intermediate place between forms of life already known, may be said, so far as it is intermediate, to be evidence in favour of Evolution, inasmuch as it shows a possible road by which Evolution may have taken place. But the mere discovery of such a form does not, in itself, prove that Evolution took place by and through it, nor does[{236}] it constitute more than presumptive evidence in favour of Evolution in general.
It is easy[270] to accumulate probabilities—hard to make out some particular case in such a way that it will stand rigorous criticism. After much search, however, I think that such a case is to be made out in favour of the pedigree of the Horse.
Of this famous instance we have already heard, and since it will be examined at length in the following chapter, we will not dwell further upon it here.
So obvious indeed is this deficiency for evolutionary requirements of the Geological record, that Professor Haeckel attempts to supply the want by boldly interpolating a number of periods during which the metamorphoses occurred, but of which no record was left. He assumes that between the epochs of depression, when fossils were deposited beneath the water, there were other epochs of elevation when the land was dry and no deposits could occur, and he supposes that the abrupt changes of flora and fauna exhibited by successive formations, are due to the lapse of time of which we have no organic record in what he styles these "Ante-periods."
As to this summary mode of loosing the Gordian knot, it will be sufficient to quote Professor Huxley's verdict: "I confess this is wholly incredible to me."[271] And although in his favourable review of Haeckel's book[272] he showed himself far more tolerant of[{237}] gratuitous speculations, than his utterances on other occasions might have led us to expect, upon this point he declared: "I fundamentally and entirely disagree with Professor Haeckel."
We may sum up the testimonies of which the above are representative in the words of two authorities by no means hostile to Evolution. M. Edmond Perrier,[273] having shewn how this theory is suggested by the successive developments of type, and how the phenomena of organic life seem to harmonize with it, thus continues:
Unfortunately, when we descend to details, such palæontological gaps present themselves that every sort of objection is possible. The chain which morphology has allowed us to piece together is continually snapped when we essay to travel back into the past.... The art of distinguishing realities from phantoms of the imagination is what has made modern science so great and so mighty. She is strong enough to win honour by avowing ignorance, and because men see her always determined to speak the truth, they gradually realize that she is not dangerous.
And in his Presidential address to the Linnean Society, May 24, 1902, Professor S. H. Vines thus expressed himself as to the genealogical table of organic life, which ever since the doctrine of Evolution was accepted, it has been sought to construct:
Though here and there fragments of the mosaic[{238}] seem to have been successfully pieced together, the main outlines, even, of the great picture are as yet but dimly discernible.
The fact that organic Evolution should have proceeded so far as it has within such limits of time as may reasonably be allowed, admits, to my mind, of no other interpretation than that variation is not indeterminate, but, as Lamarck and Nägeli have urged, there must exist in living matter a certain inherent tendency or bias in favour of variation in the higher direction. It is this tendency or bias that I venture to regard as the primordial factor.
But it is precisely such an inherent tendency of organic life to develop on predetermined lines, which Darwinians and other advocates of Evolution by the agency of physical forces alone, vehemently repudiate as fatal to their whole system.
[Since Professor Williamson wrote, the opinion has been adopted that for the very reason which induced him to place the Sharks above the Cycloids and Ctenoids, their relative positions should be reversed. The Sharks being a more "generalized" type, with features more akin to those of land-dwelling reptiles, and the others more "specialized" for purely aquatic conditions, the latter, it is argued, are a higher evolutionary product. As a necessary corollary it is assumed that vertebrate life originated, not, as had been supposed, in the sea, but in swamps or lagoons on the shore-line. It must, however, remain a question how far the facility with which theories can thus be modified according to requirements, is calculated to inspire confidence in them.]