PALAEONTOLOGY AND EVOLUTION.

Otago Witness, Issue 2541, 26 November 1902, Page 70

PALAEONTOLOGY AND EVOLUTION.

Bt Dinobnis. Palaeontology is one of the younger branches of science, but it has already * lot of good work to its name. Some folk would have it that it brings no support to the doctrine of evolution ; but in that I think they are very greatly mistaken. Apart from the overwhelming proofs from embryology* there are, perhaps, none which more markedly emphasise the truths of ! development .than do the evidences from fossil remains of extinct organisms. "For a time it was thought that palaeontology yielded somewhat negative evidence in regard to progressive evolution ; now, with fuller knowledge of the facts, evolutionists would be almost- content to base the doctrine of descent on the palseontological evidence alone." "It is the task of palaeontology to spell out the history of the past, so tar as that can be deciphered from the fossilbearing rocks, to trace the risrand decline of races, to disclose the sublime spectacle of life's progress." He is the specialist who has chosen for himself the task' of unravelling for us the story of the things that have been — the plants and animals of the earth both in its earlier and later jeons. One of the latest and most striking trifles picked up by the palaeontologist is Here represented. This sketch shows a restored

outline of the fossil skull of Pithecanthropus erectus, "the upstanding ape-man," found in Java in 1894 by Dr Eugene Dubois, and now very generally admitted by authorities to be a true "link" such as some of our reactionary friends are always asking for, but never wishing to see. When Dr Dubois arrived home with his "find,"' he very properly submitted it to all the specialists of Europe, who, after very exhaustive examination and discussion, pretty unanimously decided it to be without doubt the remains of a human or semi-human being, though of a .type hitherto quite unknown to science. I must mention that along with the skull and a few teeth a thigh bone, was got, which has also been found to possess characters of undeniably intermediate kind. Even considered as an ape, which two ov three specialists inclined to consider it, the original owner of those bones would strll rank as a "link" of striking quality, for it walked erect as we do, while the braiu-box has double the capacity of the crania of anthropoid apes presently axisting. Add to this that it is only in ~ brain measurement one-third less than is found in low human races and onehalf less than obtains in Europeans, and the comparison is sufficiently striking. In his great work, "Man : Past and Present," Mi", A. H. Keane says : " Since their discovery, these remains have been subjected to the strictest scientific scrutiuy, with the result that their human character has been placed beyond reasonable doubt. They have, indeed, been described by some anatomists as rather prehuman than actually human, but nobody now denies that they at least represent a form intermediate between man and the higher apes, or rather, between man and the generalised Simian prototype, which is practically the same thing. They do not bridge over the impassable gap between man and gorilla or chimpanzee ; but they form none the less a true link, which brings man much nearer than before to the common stem from which ail have diverged." One of the greatest authorities now living — M. L. Manouvrier — concludes that "the man of Java" walked erect, was about the medium height, and a true precursor, possibly a direct ancestor, of man." Dr D. Hepburn also declares "that the femur is distinctly human, and not merely ape-li»*, that it ante-dates all other human remains hitherto discovered, and that of living, races nearest akin are the Australians, Andamanese, and Bushmen."

As Mr Keane says : "This pliocene inhabitant of Java may thus, in a sense, be taken as the long-sought-for "first man," and as it is not very probable that lie can have had any undoubtedly human precursors elsewhere, the IndchMa'aysian intertropical lands may also, with some confidence, be regarded as the cradle of the human family." ... In support of this view comes the opportune discovery made by Dr Noetling in 1894 of chipped flints and human leg and arm bones in beds of Pliocene age in Upper Burma. These discoveries lift the question of the immense antiquity of the human family out of the region of doubt, and make of it a positive certainty. Upon the social state, mental calibre, and general surroundings of the actual being who, when alive, owned these fragmentary fossil bones, I do nob at present say anything at all. With a poet of to-day : We figure him a savage, With hands to xudclv chap» A weapon for hi.? uses; Low templed like the ape, With large projecting eyebrows, And ja-ws that widely gape; With hairy hide, unclad, 01 clad In winter with the skir Of some fierce brute his cunning caught By stealthy stalk 01 gin, Or by a happy biow of chit, That to the brain broke ilk

1 What the brain of this early sketch <t* humanity was like may be inferred from,* glance at the second diagram. In it Pithecanthropus erectus, .a young chimpanzee, and the famous Neanderthal and Cro-Magnon skulls may be conveniently studied. Casts of these remarkable objects can, I am told, now be seen in the Museum of Natural History, Dunedin.

Leaving for the present these fossil bones of our far-away precursor, let us take something with flesh and blood for our nexfe text. Take the horse, which in^ its hundreds run "tin our streets, stations/ and racecourses. A truly familiar animal, .and a noble, though, not always nobly treated. To- those who take a scientific- interest -in — the' horse nothing is more noticeable about' it than its wonderful one-toed 1' foot.. In_ a way the horse's- foot is the most highlyspecialised pedal ozvan to be found. iia.' nature. As a thing to work with, the hand * of man beats the rest of creation, hollow, of course; but as a thing to run with ther» , is nothing quite comparable to the foot of the horse. And about this beautiful foot the most noticeable thing is the single solid! nail—the hoof. The other wonders have to be looked for beneath the skin. Dissection shows the foot of the horse to consist «f a single toe—the extremity of the foot, that is. Research has made the fact quito clear that this solitary digit is the analogue of the middle toe in five-toed mammals. A little research on one's own part, even such as may be conducted in a museum —or, failing that, in a knacker's yard—will show what remains of the four missing digits. It is not much, but it means much. W© find, in shoTt, distinct bony ruddments of" two toes still remaining —two thin, tapering "splint-bones," lying one on each 'side of the bone which carries at its- tip tihe perfectl-" developed single hoof. Now, if there was no other evidence in existence these bony splints would not prove much; but as a matter of fact there is evidence in plenty to prove that the one-toed horse' of the present is descended from a five-toed ancestor of the past. The set of diagrams here reproduced is only a part of the series of horse ancestors already recovered from the stratified rocks by the labours-of the At the (d) we have-

top a diagram of- a - fossil horse's toe, almost identical in structure -with that of presently existing horses. Th« "splintbones" are larger, but there is no tr,ace of.hoofs Next we have two distinct rudimentary hoofs, as shown at (c); while beneath, at (b), these ap-' pear more largely developed. At (a) is figured a foot which hardly at all resembles anything equine as we now know it, and yet it is the foot of am undoubted horse ancestor. Beginning at the bottom these fossils are -from Eocene, Upper Eocene, Upper Miocene, and Pliocene strata. Lately a form showing a rudimentary fifth toe has been found in Lower Eocene strata in America, and there is little reason indeed for doubting but chat, as palseontological research goes on, every ii nt in the chain of equine development will • ultimately be recovered' from the rocks. Of course, it it - not pretended that the fossil forms already found are necessarily to be looked upon as.the actual ancestors of present-day horsaa, but merely that some of them almost certaialy are so, while others represent collateral and entirely extinct branches. Another point to be remembered is that structural changes in the hoof have been accompanied by corresponding changes ia all parts "of the anatomy. If now the evolution of the horse has been along lines which can be traced back until we come in sight of a five-toed ancestor, it is reasonable to ttxpeci some indication of such evolution in the individual development of the horse of to-day. There is an abundance of sucb, indication, but as this arlicle is already longer than it should be, I will merely} allude to a few of. them*

quoting from "The Penycuik Experiments ,'*• by Professor James Cossar Ewart. Am t« its evolution from unlike progenitors, Professor Ewart says; "The biologist is as satisfied that the horse has descended from five-toed ancestors as the astronomer is that the earth moves, round the sunj and he knows that not very long ago, geologically speaking, all horses had thrae complete digits' borne by the fore limb correspond digits' form by tht fore limb correspond to the fore, middle, and ring fingers in man, the hind digits to our thret middle toes." "In a five-weeks' embryo (horse) there are rudua&ato a£ three digits, mi at

■ix weeks the foot is » miniature of that of the rhinoceros." "Occasionally a foal is born with two hoofs on one or more of it* limbs ; at very long intervals a foal appears with three hoofs on one or more of its limbs. . . I have in my possession four specimens showing extra digits in the horse." "In the ancestors of the horse, as in ourselves, there were two distinct bones in tne forearm, the radius and ulna. In. all the works dealing with the skeleton of the horse the ulna is described as incomplete. It is said to terminate in a slender process some distance from the lower end of the radius. In very young horse embryos I find the ulna is not only as complete but nearly as. large as the radius. But it is often complete, though not entirely- ossified, in foals, and occasionally complete in the adult. In the skeleton of the horse placed by Sir William Flower in the entrance hall of the Natural History Museum, London, there is a complete ulna. . . In having at times a complete ulna in the horse we have another instance of reversion."

These fragmentary instances might with ease be largely added to. Such as they are, their bearing upon the doctrine of descent aeems to me to be obvious.