Anthropoidea

“ What we know positively [66] is that man exists, and that in physical structure he is very closely related to the anthropoid apes. What we have excellent reason to feel assured of is that man has descended from the lower animals, and in all probability from an ape-like ancestor. We know that one or more species of anthropoid apes have become extinct, and can reasonably conjecture that one ancient species became modified into the form of man. We know that human remains have been found that, to some small extent, fill the gap between man and the ape. ”

“ Nevertheless, the ancestors of man must have gone on acquiring all the distinctive human features during this period, and especially gaining increased volume of brain. If we could find entire skeletons of our Miocene and Pliocene progenitors, analogy leads us to suppose that naturalists would arrange them as at least two, if not more, separate species of the genus Homo. Whether we should call them men or not is a mere matter of nomenclature; but that such links in the chain of evolution must then have existed seems to me indisputable. ”

“ The next question is, how the facts of palæontology agree with these most important results of comparative anatomy and ontogeny. The fossils are the true historical 'medals of creation,' the palpable evidence of the historical succession of all those innumerable organic forms which have peopled the globe for many millions of years. Here the question arises, If the known fossil specimens of Mammalia, and particularly of Primates, give proof of these Pithecometra-theses, do they confirm directly the descent of man from ape-like creatures? ”

“ The present treatise, devoted to anthropogeny, is divided into two parts: the first, ontogeny, or the history of individual human organisms, concerns itself chiefly with germ history or embryology; and the second, on phylogeny, is a history of the evolution of the various animal forms, from which man has descended in the course of countless ages. Phylogeny is thus a history of evolution, and embraces the sub-sciences of paleontology and genealogy. ”

“ In a zoological point of view they include man and the existing races of animals, as well as extinct races which appear to have been contemporaneous with indigenous species. To the archæologist they are rich in records of that primeval transition in which the beginnings of history lie. How early in that closing geological epoch man appeared, or how late into that archæological era the extinct fossil mammals survived, are the two independent propositions which the sister sciences have to establish and reconcile. ”

“ On this doctrine of the extermination of an infinitude of connecting links between the living and extinct inhabitants of the world, and at each successive period between the extinct and still older species, why is not every geological formation charged with such links? Why does not every collection of fossil remains afford plain evidence of the gradation and mutation of the forms of life? We meet with no such evidence, and this is the most obvious and plausible of the many objections which may be urged against my theory. ”

“ It is a question of the discovery in Tertiary strata near Trinil, Java, of bones which seem to have belonged to a being intermediate between man and the anthropoids. This could be a precursor and perhaps an immediate ancestor of the human species, the link, heretofore lacking, of the chain which, according to the theory of evolution, ought to unite without interruption Homo sapiens with the rest of the animal kingdom. ”

“ The enormous extension of geological research in recent times has made us acquainted with a vast number of extinct organisms, so vast that in some important groups—such as the mollusca—the fossil are more numerous than the living species; while in the mammalia they are not much less numerous, the preponderance of living species being chiefly in the smaller and in the arboreal forms which have not been so well preserved as the members of the larger groups. ”

“ It is a pity that the theory of our evolution from the primordial protoplasm in an inclusive line through every living species should now be considered old-fashioned. I like to imagine that among my remote ancestors every living thing is represented—it gives them a family interest. And if, further, I can persuade myself that I have been everything, at one time or another, from a bluebottle to a giraffe—why, then I can brown-study for ever. ”

“ Inasmuch as Petite Anse and Natchez have furnished more species of fossil vertebrates than any other localities in their States, and likewise human relics supposed to be of equal age with the extinct mammals, these places will receive especial attention. ”

“ If the extinct species of plants and animals of the later geological periods were the progenitors of the living species, and gave origin to them by variation and natural selection, where are all the intermediate forms, fossil and living, through which the lost types must have passed during their conversion into the living ones? And why do we not find almost everywhere passages between the nearest allied species and genera, instead of such strong lines of demarcation, and often wide intervening gaps? ”

“ On the Affinities of extinct Species to each other, and to living forms.—Let us now look to the mutual affinities of extinct and living species. They all fall into one grand natural system; and this fact is at once explained on the principle of descent. The more ancient any form is, the more, as a general rule, it differs from living forms. But, as Buckland long ago remarked, all fossils can be classed either in still existing groups, or between them. That the extinct forms of life help to fill up the wide intervals between existing genera, families, and orders, cannot be disputed. ”

“ We possess no pedigrees or armorial bearings; and we have to discover and trace the many diverging lines of descent in our natural genealogies, by characters of any kind which have long been inherited. Rudimentary organs will speak infallibly with respect to the nature of long-lost structures. Species and groups of species which are called aberrant, and which may fancifully be called living fossils, will aid us in forming a picture of the ancient forms of life. Embryology will often reveal to us the structure, in some degree obscured, of the prototype of each great class. ”

“ For instance, the Anthropoid line would split into four, standing respectively for the Gibbon, Orang-utan, Chimpanzee, and Gorilla.
The fork of the Y representing man would not branch and rebranch so intricately as the fork representing the monkeys. Many zoölogists regard all the living varieties of man as constituting a single species, while even those who are inclined to recognize several species limit the number of these species to three or four. Then too the known extinct varieties of man are comparatively few. ”

“ We may perhaps be reminded again that all the species of these "older" rocks are extinct species. I have already suggested the grave doubts on this point, regarding the great mass of the lower forms of life, plant and animal; but we will let that pass. But let us take some of the "late" Tertiary and Pleistocene mammals, which cannot be distinguished from living species, and how do we fare? It is the same old story; the moderns are degenerate dwarfs. ”

“ In the next place, Physical Anthropology, not only in respect to [37] human palaeontology, but in general, is as barren of explanations as it is fertile in detailed observations. The systematic study of heredity as it bears on the history of the human organism has hardly begun. ”

“ The Argument from Persistent Types.—If good cases of graduated form-series were not available at the time of the "Origin" or before, the evolutionist of the period could still find in paleontology one sort of evidence decidedly unfavorable to the chief hypothesis then opposed to his own—that of extensive "revolutions of the globe," wholesale obliterations of faunas, and thorough-going new creations of the entire organic world. This evidence lay in the persistence of many orders and certain species through more than one geological epoch. ”

“ The remains of Mammalia discovered in a fossil state include an immense number of species, and furnish examples of almost every living genus, and of numerous genera, and even orders, of which no existing species are known. Yet amidst the vast accumulations of the skeletons of the higher orders of vertebrata contained in the tertiary deposits, and in the superficial drift, belonging to species which have successively appeared on the surface of our planet, flourished for indefinite periods of time, and then become annihilated, no vestiges of Man, or of his works, have been detected. ”

“ Paleontology has triumphed over the weakness of the evidence, which Darwin admitted was serious, by filling in many of the missing links.
Paleontology has been criticised on the ground that she cannot pretend to show the actual ancestors of living forms because, if in the past genera and species were as abundant and as diverse as we find them at present, it is very improbable that the bones of any individual that happened to be preserved are the bones of just that species that took part in the evolution. ”

“ According to the doctrine of descent, when several species of animals living at the same time show close resemblance in structure, it is inferred that this resemblance must have been inherited by all from one ancestral species. Now of all the mammalia, or animals which suckle their young, those whose structure brings them closest to man are the apes or monkeys, and among these the catarhine or near-nostrilled apes of the Old World, and among these the group called anthropoid or manlike, which inhabit tropical forests from Africa to the Eastern Archipelago. ”

“ The structure of the greater number, even of the earliest fossil Mammalia, differs in so few essential points from that of the living representatives of their respective Orders, that I forbear to enter on details which would indeed abound with evidences of creative design, but would offer little that is not equally discoverable in the anatomy of existing species. I shall, therefore, limit my observations to two extinct genera, which are perhaps the most remarkable of all fossil Mammalia, for size and unexampled peculiarities of anatomical construction ”

“ So far from palaeontology lending no support to the doctrine of evolution—as one sees constantly asserted—that doctrine, if it had no other support, would have been irresistibly forced upon us by the palaeontological discoveries of the last twenty years.
If, however, the diverse forms of life which now exist have been produced by the modification of previously-existing less divergent forms, the recent and extinct species, taken as a whole, must fall into series which must converge as we go back in time. ”

“ But it has its limitations, and it goes without saying that the more complete the fossil skeleton of a vertebrate, or the remains of an arthropod, the more complete will be our conception of the form of the extinct organism. It may be misleading in the numerous cases of convergence and of generalized forms which now abound in our palæontological collections. We can well understand how guarded one must be in working out the restorations of dinosaurs and fossil birds, of the Permian and Triassic theromorphs, and the Tertiary creodonts as compared with existing carnivora. ”

“ The arts of living races help to elucidate what is obscure in those of prehistoric times by the process of reasoning from the known to the unknown. It is the work of the zoologist which enables the palaeontologist to reconstruct the forms of extinct animals from such fragmentary remains as have been preserved, and it is largely from the results of a comparative study of living forms and their habitats that he is able, in his descriptions, to equip the reconstructed types of a past fauna with environments suited to their structure, and to render more complete the picture of their mode of life. ”

“ The sparse remains of Dryopithecus, the species in question, with some few other fossils of doubtfully anthropoid species, save us from a total blank, and open the vista to a myriad of active arboreal creatures which had their dwelling-place in the old-time European forests, but have almost utterly vanished from human knowledge. ”

“ That the potentiality of all the characters of all the forms that have existed, pterodactyls, dinosaurs, butterflies, birds, etc. etc., including the characters of all the varieties of the human race and of human individuals, must have been present in the primordial ancestral protoplasm, is a truism, for if the possibility of such evolution did not exist, evolution would not have taken place. ”

“ If we suppress the former and whatever bears upon the straightening of the trunk in arboreal life—a straightening which in no way implies a vertical position of the lower limbs—there is nothing left particularly to the credit of the anthropoids. The other distinctive characteristics of man and the anthropoids are secondary, but lead to the same conclusions. Hence the two groups should be separated in classification, and the anthropoids continue monkeys. ”

“ We might also expect that when a country is now characterised by special groups of animals, the fossil forms that immediately preceded them shall, for the most part, belong to the same groups; and further, that, comparing the more ancient with the more modern types, we should find indications of progression, the earlier forms being, on the whole, lower in organisation, and less specialised in structure than the later. Now evidence of evolution of these varied kinds is what we do find, and almost every fresh discovery adds to their number and cogency. ”

“ When the palæontologist has completely established his position, that all the organic phenomena of primeval times have resulted from the impress of original structure, in opposition to the theory of progressive development and transmutation of species; and when he can trace, also, corresponding changes in the mineral formations in which the fossil remains are imbedded, the important inquiry has still to be made into the causes of the extinction of so many races of the animal and vegetable kingdoms. ”