The Old Riddle And The Newest Answer Part 15

That these facts are indeed most remarkable and deserving of all attention, cannot be questioned. But before we can agree that they are conclusive and demonstrative in Professor Huxley's sense a good many considerations require to be carefully weighed.

(i.) It is obvious, in the first place, that here as in all other instances which we have seen, the one thing is lacking which is really wanted in order to prove Evolution, namely evidence of one species gradually shading off into another. The creatures of which we have heard, are each isolated from the rest, and indeed very much isolated, for each belongs to a different _genus_,[279] which shows that the differences between them are substantial. They are, in fact, farther apart from one another, than the zebra or the donkey from the horse, for both of these are cla.s.sed in the genus _equus_,--or than the Bengal tiger is from the domestic p.u.s.s.y-cat, both belonging to the genus _felis_.

These various ungulate forms thus stand a long way from one another, and if they were once connected together by a bridge, or rather a causeway, we ought certainly to find some traces of it, and not always of those particular types which require to be united. If we suppose the very distinct species actually known to have been the piers of such a bridge, yet what has become of the arches? Till some vestiges of these be found, or, at least, some positive evidence that arches there actually were, can it be said that the story of the fossil _equidae_ furnishes convincing testimony on behalf of the supposed evolution? Affinities these various forms undoubtedly exhibit: it has yet to be shown that affinities necessarily imply descent.

There is, however, something even more remarkable. We have seen that Professor Huxley prognosticated beforehand the discovery of _Eohippus_, and specified pretty nearly the features it would be found to present.

In the same way, Professor Marsh[280] antic.i.p.ates and describes a still more remote ancestral form, for which, though it has not yet been found, he has provided an appellation, _Hippops_. But if either Professor really believes in Evolution, why does he take for granted that we shall chance upon one particular form, standing like a solitary outpost by itself, and not upon any other trace of the stream of life whereof it was but one transient phase? Such predictions may be evidence that the occurrence of these progressive forms is regulated by something a.n.a.logous to Bode's Law of interplanetary distances, and that their discovery may be looked for at certain intervals. But the very fact that their actual position can be so accurately specified serves to show that it is very definitely fixed.

(ii.) Moreover, a very grave difficulty at once suggests itself, of which Professor Huxley makes no mention. The horse as we now have him, _Equus caballus_, is a native of the Old World, and has been introduced to America only since the time of Columbus. There had, it is true, been horses in America previously,--belonging to the genus _Equus_, perhaps even to the species _caballus_,--they had, however, been long extinct, and no memory of them remained. But, as will be noticed, the pedigree given by Professor Huxley consists almost entirely of American animals, to which category belong all whose names terminate in _-hippus_, and these cannot with any reason be a.s.signed as progenitors to the European horse. As Sir J. W. Dawson observes:[281]

In America a series of horse-like animals has been selected, beginning with the _Eohippus_ of the Eocene--an animal the size of a fox, and with four toes in front and three behind--and these have been marshalled as the ancestors of the fossil horses of America.... Yet all this is purely arbitrary, and dependent merely on a succession of genera more and more closely resembling the modern horse being procurable from successive Tertiary deposits often widely separated in time and place. In Europe, on the other hand, the ancestry of the horse has been traced back to _Palaeotherium_--an entirely different form--by just as likely indications, the truth being that as the group to which the horse belongs culminated in the early Tertiary times, the animal has too many imaginary ancestors. Both genealogies can scarcely be true, and there is no actual proof of either. The existing American horses, which are of European origin, are, according to the theory, descendants of _Palaeotherium_, not of _Eohippus_; but if we had not known this on historical evidence, there would have been nothing to prevent us from tracing them to the latter animal. This simple consideration alone is sufficient to show that such genealogies are not of the nature of scientific evidence.

(iii.) Even apart from this fundamental difficulty, there is much diversity as to the precise genealogy. We may compare together the lines of ancestry favoured--(1) by Professor Huxley, (2) In a case exhibited in our Museum of Natural History to ill.u.s.trate the subject, (3) By Mr.

Mivart,[282] (4) By Mr. Lydekker,[283] (5) In The _Evolution of the Horse_, a pamphlet issued, January, 1903, by the American Museum. This last gives the very latest version of the pedigree, but, naturally, of the American Horse alone.

------------------------------------------------------------------------------- _Huxley._ _British_ _Mivart._ _Lydekker._ _American _Museum Case._ Museum._ ------------------------------------------------------------------------------- Equus Equus Equus Equus Equus Pliohippus Protohippus Hipparion Hipparion Hipparion Hipparion Protohippus Protohippus Hypohippus Miohippus Anchitherium Anchitherium Merychippus Anchitherium Anchitherium {Anchilophus {Mesohippus Mesohippus Protohippus Pachynolophus {(_form allied to_) { (_2 species_) {Mesohippus Epihippus Orohippus { (_2 species_) {Hyracotherium Protorohippus Eohippus Hyracotherium Phenacodus {Systemodon Eohippus _An undiscovered ancestor_ (Hippops) -------------------------------------------------------------------------------

It will be observed, that whereas _Hipparion_ is disallowed by Professor Huxley as not being in the direct line of descent, in all the other genealogies he appears as the immediate ancestor of _Equus_. Also that in all these tables, Old World and New World forms are used indifferently to supply progenitors for the same successor. Also that there is no agreement at all as to the earlier ancestry. It would likewise appear that even the existence of _Eohippus_ himself is not beyond question, for in our Museum galleries and guide-book his name always has a note of interrogation appended. The American authorities give an antic.i.p.atory sketch of the limbs of the ancestor which still remains to be discovered.

There is something even more remarkable.

DEVELOPMENT OF EQUIDae.

/ +---------------------------------------------------+ Recent. { Equus Caballus.{*} +---------------------------------------------------+ / { Equus Stenonis.{*}{**} E. Sivalensis.{*}{**} &c. Quaternary. { Hippidium.{**} E. America.n.u.s.{**} &c. { +---------------------------------------------------+ / { { Pliohippus. / { { Pliocene. { Hipparion.{*}{**} Protohippus. { { { { { { +---------------------------------------------------+ { / TERTIARY. { { { Miocene. { Hypohippus. Parahippus. { { Miohippus. Anchitherium.{*} { { Merychippus. { { Mesohippus. { { +---------------------------------------------------+ { / Epihippus. { { Orohippus. Hyracotherium.{*} { Eocene. { Protorohippus. Pachynolophus.{*} { { Eohippus. { Phenacodus. +---------------------------------------------------+ Hippops (undiscovered). SECONDARY. No trace of Mammals except small Marsupials and Insectivora.

{* Indicates an inhabitant of the Old World. All others are American.}

{** "Not in direct line of ancestry."}

Huxley's lecture exhibiting the pedigree we have been considering was delivered in 1876. We have already seen that six years earlier he had declared himself satisfied, after much search, that though other genealogies might be doubtful, we had in the case of the Horse something really satisfactory. But the pedigree of 1870--which he thus indicated as scientifically established--was totally different from that of 1876, and was acknowledged as erroneous by the very acceptance of the latter.

In 1870 the ancestry presented for _Equus_ consisted of _Hipparion_, _Anchitherium_, and _Plagiolophus_. Of these, _Hipparion_ was in 1876 specifically disallowed as a direct ancestor: _Anchitherium_ was displaced by _Miohippus_, and although we are told that these creatures "correspond pretty nearly," the Horse cannot be descended from _both_, especially as they dwelt in different hemispheres. Finally _Plagiolophus_ disappears from the amended pedigree altogether. Nothing could more vividly ill.u.s.trate the danger of such speculations than that an authority so clear-headed and conscientious as Professor Huxley should thus proclaim his acceptance of a genealogy which he had on after information to renounce. Nor to him alone have such misadventures happened. Mr. Darwin too thought the claim of _Hipparion_ to ancestral equine rank to be beyond dispute. "No one will deny," he wrote,[284]

"that the _Hipparion_ is intermediate between the existing horse and certain older ungulate forms." Yet, as we see, this has been denied by his champion Huxley himself.

(iv.) The materials available for the reconstruction of these various equine forms, are far less satisfactory than might easily be supposed.

As a rule, each is known to us only by small fragments of its skeleton, so that we can have no a.s.surance as to what the whole animal was really like, or even that all parts a.s.signed to one creature really belonged to him. We can accordingly feel no certainty that if we could see any of these as a whole we should find it possible to suppose that the horse descended from it. Thus in _Hippidium_, an American genus closely allied to _Equus_, it is at least doubtful whether the digits did not terminate in claws.[285] One species of _Hippidium_ is known only by a solitary tooth. Of _Hyracotherium_ only the skull has been found: of _Orohippus_ only parts of jaws and teeth and a forefoot: of _Epihippus_, "only incomplete specimens."[286] Accordingly, Professor Williamson, speaking of the discoveries of Professor Marsh and others, thus expresses himself:[287]

Beyond all question, some of the gaps that have hitherto separated the three animals [_Anchitherium_, _Hipparion_, and _Equus_] are filled up by these discoveries; but I want yet more evidence before I can arrive at the conclusion that the doctrine of Evolution is proved by these facts beyond the possibility of question. It appears to me that before I can unhesitatingly give to the testimony of these fossil horses the full value I am asked to do, I must know more about them than is at present possible. It will not be enough that the limbs and teeth of these creatures indicate trans.m.u.tation, but such trans.m.u.tation must be evidenced by every part of the animal. This demand is especially applicable to the stages which intervene between the Hipparion and the horse....

Myriads of individuals must have existed to effect the gradual shading of the one into the other in every part of its body.

(v.) It should likewise be remarked that in one not unimportant particular, the plates so commonly given to ill.u.s.trate the horse's ancestry do not fairly represent the facts. It would appear from them that all the animals were much of a size, which doubtless greatly a.s.sists the imagination in picturing them as all in one line of descent.

But as a matter of fact they differed in stature extremely, and the remoter supposed progenitors were comparative pigmies. _Hyracotherium_, for instance, was "about the size of a hare,"[288] and according to Professor Cope, _Orohippus_ was the exact counterpart of this diminutive steed. The hypothetical _Hippops_, which Professor Marsh locates in the lower Tertiary or upper Secondary rocks, can, he thinks,[289] now "be predicated with certainty;" and amongst other things it "probably was not larger than a rabbit, perhaps much smaller." Sometimes, so far as evidence goes, it even seems that in respect of size there was deterioration instead of advance as the lineage progressed. Thus _Epihippus_, found in the Upper Eocene, is considerably smaller than _Protorohippus_, found in the Middle Eocene; "but," says the American pamphlet,[290] "no doubt there were others of larger size living at the same time," which will scarcely be called convincing.

[Ill.u.s.tration: "THE PEDIGREE OF THE HORSE," FROM THE AMERICAN MUSEUM.

"THE PEDIGREE OF THE HORSE," FROM HUXLEY'S _LECTURES ON EVOLUTION_.]

(vi.) Worthy of notice also is "the remarkable circ.u.mstance that in the line of evolution culminating in the modern Horse, a parallel series of generically identical or closely allied forms occurs in the Tertiaries of both Europe and North America, from which it has been suggested that on both continents a parallel development of the same genera has simultaneously taken place."[291] And, as we have seen, while the American pedigree must have been entirely different from the European, it terminates equally in both continents with the genus _Equus_, if not actually with _Equus caballus_.[292] But, on any mechanical system of evolution, it is impossible to suppose that developments conducted along separate roads could thus be brought to meet in one terminus.[293] Mr.

Darwin did not conceive it possible that the same species should be produced twice over, "if even the very same conditions of life, organic and inorganic should recur,"[294] and the production of genuine horses, not only in widely diverse circ.u.mstances, but through totally different ancestors, must appear still less conceivable. Consequently, says Mr.

Mivart,[295] "it follows from this generic ident.i.ty, that cla.s.sification will be no longer Darwinian, but one more Aristotelian, and will regard, not the origin but the _outcome_ of development, whether of the individual or the species."

(vii.) There is, however, another consideration more serious than any of the above. In order to set the theory of genetic Evolution upon a sound and substantial basis, it is not sufficient to show that the last ungulate is lineally descended from the first,--_Equus_ from _Eohippus_, _Hyracotherium_, _Phenacodus_, or _Hippops_,--but that this first ungulate himself--whichever it was--has been, or at least may have been, similarly developed from a non-ungulate Mammalian ancestor, the common parent of all the protean forms a.s.sumed by his progeny. To develop all these from one original, through a graduated series in each case, by the infinitesimal process of descent with modification, would require a period of time inconceivably long--immensely longer than that required to change one ungulate into another. Ungulates, as has been said, are a highly specialized type of Mammals, and although they walked on the nails of five digits instead of only one, a vast amount of Evolution would be required to bring them even to this point, from that whence all Mammals are said to have started. There must also have existed, while this development was in progress, a teeming and mult.i.tudinous mammalian life, as raw material for its operations--and of this at least _some_ trace should remain.

But, so far as we know, the first Ungulates made their appearance upon earth quite as soon as did any other mammals from which they could possibly have sprung. _Phenacodus_, is in fact described as,[296] "The most primitive Eocene mammal yet discovered." He appears in the Lower Tertiary; while the Secondary and Mesozoic rocks beneath,--the whole period covered by which would be none too long for the evolution of Tertiary mammals generally,--are practically devoid of mammalian remains altogether, exhibiting only a few small marsupials, from which we can no more suppose _Phenacodus_ and the huge and various beasts who were his Eocene contemporaries to have developed, than from opossums the size of shrew-mice.

It also complicates matters not a little to find that when placental mammals first show themselves all over the world at the beginning of the Eocene,--while this highly specialized order of the Ungulates seems to have been much the most numerous, it had a host of contemporaries, of extreme diversities of structure:--as for instance Unguiculates (or clawed animals) allied to the Hyena and the Fox, Rodents (gnawing animals) akin to the Squirrel, as well as Whales and Bats. Of the Cetaceans, Sir J. W. Dawson tells us:[297]

The oldest of the whales are in their dent.i.tion more perfect than any of their successors, since their teeth are each implanted by two roots, and have serrated crowns, like those of the seals. The great Eocene whales of the South Atlantic (_Zeuglodon_) which have these characters, attained the length of seventy feet, and are undoubtedly the first of the whales in rank as well as in time.

This is perhaps one of the most difficult facts to explain on the theory of Evolution.... "We may question," says Gaudry,[298] "these strange and gigantic sovereigns of the Tertiary oceans as to their progenitors--they leave us without reply." ... Their silence is the more significant as one can scarcely suppose these animals to have been nurtured in any limited or secluded s.p.a.ce in the early stages of their development.

The Bats, as is obvious, would require quite as much transformation from the generalized mammalian type as the Whales themselves, though in quite another direction. But they appear with their wings fully developed, in the Eocene, in both Hemispheres.

Gaudry thinks [writes Sir J. W. Dawson][299] that it is "natural to suppose" that there must have been species existing previously with shorter fingers[300] and rudimentary wings; but there are no facts to support this supposition, which is the more questionable since the supposed rudimentary wings would be useless, and perhaps harmful to their possessors. Besides, if from the Eocene to the present, the Bats have remained the same, how long would it take to develop an animal with ordinary feet, like those of a shrew, into a bat?

Such instances are by no means singular, nor are like difficulties confined to the Eocene. In the Miocene above, about the time when Anchitherium flourished, there appeared a family with whom he might claim relations.h.i.+p, for they were not only akin to the Ungulates but Perissodactyles, or "odd-toed," like himself. These were the "Proboscideae"--"the beasts that bear between their eyes a serpent for a hand," in other words the Elephants and their allies. These, like other families, amongst their earliest representatives included the giants of their race, for some of their Miocene specimens[301] are about half as large again as the largest of our modern elephants. Professor Ray Lankester has recently declared[302] that we now understand the genetic affinities of these creatures, whose faces have been pulled out into trunks with the nose at the extremity, and in support of his statement he adduces the features of the cranium as exhibited in certain recently-discovered specimens. But how far can conclusions be called final which are based upon such partial evidence?[303] As M. Gaudry, convinced Evolutionist as he is, acknowledges, in regard of this very matter:[304]

Like the Mastodons, the Dinotheria appeared suddenly. Whence did they come? from what quadrupeds did they spring? At present we do not know.... The points of difference [from other mammals] taken as a whole, and compared with the points of resemblance, are too great to enable us to point to any relations.h.i.+p between the Proboscideans and animals of other orders as yet known to us.

Such then are some of the still unanswered questions connected with the genesis of the Horse, "the most famous instance of geological evidence"[305] which Professor Huxley selects as proving Evolution to demonstration. It is by no means easy to understand how it could ever be supposed to merit any such description. In view of the various difficulties recited above it can hardly be thought that there is satisfactory evidence even of the modic.u.m of Evolution for which alone are such arguments brought, namely within the limits of the _Equidae_.

Even were the reality of this established to the full, how would such evidence compare with that we have heard, drawn not from one corner of Organic Nature, but from a review of the great lines of its history?[306]

We find indeed that while Professor Huxley declares palaeontology to be the main support of Evolution, other authorities tell us the exact contrary.

The doctrine of organic evolution [says Sir J. W. Dawson][307] is essentially biological rather than geological, and has been much more favoured by biologists than by those whose studies lead them more specially to consider the succession of animals and plants revealed by the rocks of the earth.

Similarly Professor Williamson,[308] speaking of the efforts made to obtain evidence on behalf of Evolution, says: "Not only living, but extinct animals have been appealed to; Professor Huxley especially has, with his wonted skilfulness, made use of the latter to b.u.t.tress the geological side of the structure, which is confessedly its weakest one."

More important than all,--Mr. Darwin himself fully acknowledged that the palaeontological evidence is far short of what it should be:--and attempted to meet the difficulty by pleading the imperfection of the geological record:--a plea to be more fully considered presently.

We must not leave unnoticed the method of dealing with the geological record adopted by Professor Haeckel. Of this we have already seen a slight specimen,--- in the gratuitous and baseless a.s.sertion that the apetalous Dicotyledons date as far back as the Trias, at the very bottom of the Secondary period, by which, were it a fact, a serious Evolutionary void would be filled. In the same manner he draws a perfectly imaginary picture of the submarine forests of primeval days, in which "we may suppose" all the forms of after vegetation to have begun their career as seaweeds.[309]

But in regard of his favourite doctrine of the b.e.s.t.i.a.l origin of man, he goes much further, and prints[310] an elaborate genealogy upon which Professor Huxley in reviewing him makes no adverse remark. In this he exhibits, as a simple matter of scientific fact, an "Ancestral Series of the human pedigree," which ninety-nine per cent, of his readers will naturally suppose to be based upon palaeontological evidence. This wonderful genealogy stands thus:

1. _Monera._ 2. Single-celled Primeval animals. 3. Many-celled Primeval animals. 4. Ciliated planulae (_Planaeada_). 5. Primeval Intestinal animals (_Gastraeada_). 6. Gliding Worms (_Turbellaria_). 7. Soft-worms (_Scolecida_). 8. Sack worms (_Himatega_). 9. _Acrania._ 10.

_Monorrhina._ 11. Primeval fish (_Selachii_). 12. Salamander fish (_Dipneusta_). 13. Gilled Amphibia (_Sozobranchia_). 14. Tailed Amphibia (_Sozura_). 15. Primeval Amniota (_Protamnia_). 16. Primary Mammals (_Promammalia_). 17. _Marsupialia._ 18. Semi-apes (_Prosimiae_). 19.

Tailed narrow-nosed Apes. 20. Tail-less narrow-nosed Apes (Men-like Apes). 21. _Pithecanthropus_ (Speechless or Ape-like Man). 22. Talking Man.

The first thing to remark [says M. de Quatref.a.ges][311] is that not one of the creatures exhibited in this pedigree has ever been seen, either living or fossil. Their existence is based entirely upon theory.[312] All species, existing or extinct, are said to have been preceded by ancestral forms, which have disappeared leaving no vestige behind.... All the ancestral groups more or less ill represented in the actual organic world, do not suffice to fill up the gaps in his pedigree; from one stage to another there is sometimes too broad a gulf. Then Haeckel invents the types themselves, as well as the line of descent to which he a.s.signs them [for example No. 7, The _Scolecida_, and No. 21, _Pithecanthropus_].

This kind of "Science" does not deserve to be treated seriously. It will be sufficient to cite another observation of M. de Quatref.a.ges:[313]

If Darwin erred in regarding our very ignorance as to some degree telling in favour of his notions, he never tried to re-write the missing volumes of the earth's history, to restore the chapters which have been torn out, or to fill the blanks upon pages that have come down to us. But this is just what Haeckel does continually. Whenever a branch or a twig is lacking on his genealogical trees, whenever the transit from one type to another would appear too abrupt, were we to restrict ourselves to creatures actually known, he invents species and groups bodily, to which he unhesitatingly a.s.signs a place in phylogeny, often a part in phylogenesis. Sometimes he calls in ontogeny to countenance the discovery of supposed ancestors: but frequently he does no more than affirm their existence. He thus creates a fauna, entirely hypothetical, of which Vogt rightly said that no man ever saw a trace of it, or ever will.

It is in this fas.h.i.+on that Professor Haeckel habitually solves the Riddles of the Universe.

As Vogt himself wrote,[314] "We shall be compelled to patch and alter these genealogical trees of species, which up to this time have been set forth as the last word of Science, and especially of Darwinism."

And Du Bois-Reymond,[315] "Man's pedigree, as drawn up by Haeckel, is worth about as much as is that of Homer's heroes for critical historians."