The Meeting-Place of Geology and History Part 1

The Meeting-Place of Geology and History.

by Sir John William Dawson.

PREFACE

The object of this little book is to give a clear and accurate statement of facts bearing on the character of the debatable ground intervening between the later part of the geological record and the beginnings of sacred and secular history.

The subject is one as yet full of difficulty; but the materials for its treatment have been rapidly acc.u.mulating, and it is hoped that it may prove possible to render it more interesting and intelligible than heretofore.

J. W. D.

CHAPTER I

GENERAL NATURE OF THE SUBJECT

The science of the earth and the history of man, though cultivated by very different cla.s.ses of specialists and in very different ways, must have their meeting-place. They must indeed not only meet, but overlap and run abreast of each other throughout nearly the whole time occupied by the existence of man on the earth. The geologist, from his point of view, studies all the stratified crust of the earth, down to the mud deposited by last year's river inundations. The historian, aided by the archaeologist, has written and monumental evidence carrying him back to the time of the earliest known men, many thousands of years ago.

Throughout all this interval the two records must have run more or less parallel to each other, and must be in contact along the whole line.

The geologist, ascending from the oldest and lowest portions of the earth's crust, and dealing for millions of years with physical forces and the instinctive powers of animals alone, at length as he approaches the surface finds himself in contact with an entirely new agency, the free-will and conscious action of man. It is true that at first the effects of these are small, and the time in which they have been active is insignificant in comparison with that occupied by previous geological ages; but they introduce new questions which constantly grow in importance, down to those later times in which human agency has so profoundly affected the surface of the earth and its living inhabitants.

Finally, the geologist is obliged to have recourse to human observation and testimony for his information respecting those modern causes to which he has to appeal for the explanation of former changes, and has to adduce effects produced by human agency in ill.u.s.tration of, or in contrast with, mutations in the pre-human periods.

The historian, on the other hand, finds, as he pa.s.ses backward into earlier ages, doc.u.mentary evidence failing him, and much of what he can obtain becoming mythical, vague or uncertain, or difficult of explanation by modern a.n.a.logies, until at length he is fain to have recourse to the pick-axe and spade, and to endeavour to disinter from the earth the scanty relics of primeval man, much as the geologist searches in the bedded rocks for the fossils which they contain. He has even learned to use for these earliest ages the term prehistoric, and so practically to transfer them to the domain of the archaeologist and geologist.

It is evident, therefore, that if we seek for the meeting-place of geology and history, we shall find not a mere point or line of contact, but a series of such points, and even a complicated splicing together of different threads of investigation, which it may be difficult to disentangle, and which the geological specialist alone, or the historical specialist alone, may be unable fully to understand. The object of this little volume will be to unravel as many as possible of these threads of contact, and to make their value and meaning plain to the general reader, so that he may not, on the one hand, blindly follow mere a.s.sertions and speculations, or, on the other, fail to appreciate ascertained and weighty facts relating to this great and important matter of human origins.

This is the more necessary since, even in works of some pretension, there are tendencies on the one hand to overlook geological evidence in favour of written records, or even of conjectural hypotheses, and on the other to reject all early historical testimony or tradition as valueless. We shall find that neither of these extremes is conducive to accurate conclusions. Researches of a geologico-historical character necessarily also bring us in view of the early history of our sacred books. This may be to some extent an evil, as inviting the excitement of religious controversy; but on the other hand the fact that the early history incorporated in the Bible goes back to the introduction of man, and connects this with the completion of the physical and organic preparations for his advent, has many and important uses. It would seem indeed that it is a great advantage to our Christian civilisation that our sacred books begin with a history of creation, giving an idea of order and progress in the creative work. Whether we regard the days of creation as literal days or days of vision of a seer, or whether we hold them to be days of G.o.d and His working, suitable to the Eternal One and His mighty plan, and bearing the same relation to Him that ordinary working days bear to us, we cannot escape the idea of an orderly work in time. This, while it delivers the Bible reader from the extravagant myths current among heathen peoples, ancient and modern, predisposes him to expect that something may be learned from nature as to its beginning and progress. In like manner the short statements in Genesis respecting the early history of man have awakened curiosity as to human origins, and have led us to search for further details derivable from ancient monuments. The ordinary Christian who believes his Bible is thus so far on his way toward a rational geology and archaeology, and cannot say with truth that he is absolutely ignorant of the pre-human history of the earth. His notions, it is true, may be imperfect, either by reason of the brevity of the record to which he trusts, or of his own imperfect knowledge of its contents, but they give to historical and archaeological inquiry an interest and importance which they could not otherwise possess.[1]

[1] It is an interesting fact that the pecuniary means, the skill and labour expended in research in the more ancient historic regions, have to so large an extent been those of Christians interested in the Bible history. Yet some _litterateurs_, who have contributed nothing to these results, attempt to distort and falsify them in the interest of an unhistorical and unscientific criticism, and even to taunt the Bible as adverse to archaeological inquiry.

The earth has indeed, especially in our own time, and under the impulse of Christian civilisation, made wonderful revelations as to its early history, to which we do well to take heed, as antidotes to some of the speculations which are palmed upon a credulous world as established truths. We have now very complete data for tracing the earth from its original formless or chaotic state through a number of formative and preparatory stages up to its modern condition; but perhaps the parts of its history least clearly known, especially to general readers, are those that relate to the beginning and the end of the creative work. The earlier stages are those most different from our experience and whose monuments are most obscure. The later stages on the other hand have left fewer monuments, and these have been complicated with modern changes under human influence. Besides this, it is always difficult to piece together the deductions from merely monumental evidence and the statements of written or traditional history. There would seem, however, to be now in our possession sufficient facts to link the human period to those which preceded it, and thereby to sweep away a large amount of misconception and misrepresentation in one department at least of the relations of natural science with history.

I have called the subject with which we are to deal the meeting-place of two sciences. In reality, however, it might be embraced under the name anthropology, the science of man, which covers both his old prehistoric ages as revealed by geology and archaeology, and the more modern world which is still present, or of which we have written records. The main point to be observed is that it is necessary to place distinctly before our minds the fact that we are studying a period in which, on the one hand, we have to observe the precautions necessary in geological investigation, and on the other to examine the evidence of history and tradition. A failure either on the one side or the other may lead to the gravest errors.

In studying the subjects thus indicated it will be necessary first to notice shortly the history of the earth before the human period, and its condition at the time of man's introduction. We may then inquire as to the earliest known remains of man preserved in the crust of the earth, and trace his progress through the earlier part of the anthropic or human period, in so far as it is revealed to us by the relics of man and his works preserved in the earth. We shall then be in a position to inquire as to the form in which the same chain of events is presented to us by history and tradition, and to discover the leading points in which the two records agree or appear to differ.

It may be necessary here to define a few terms. The two latest of the great geological periods may be termed respectively the _pleistocene_ and the modern, or _anthropic_, the latter being the human period or age of man. The pleistocene includes what has been called the glacial age, a period of exceptional cold and of much subsidence and elevation of the land, in the northern hemisphere at least. The modern, or anthropic, is for our present purpose divisible into two sections--the early modern, or _palanthropic_, sometimes called quaternary, or post-glacial, and which may coincide with the antediluvian period of human history; and the _neanthropic_, extending onward to the present time.[2]

[2] The terms 'Palaeolithic' and 'Neolithic' have been used for the men of the Palanthropic and Neanthropic ages; but these are objectionable, as implying that these ages can be best distinguished by the use of certain stone implements, which is not the fact. I have preferred, therefore, to call the earlier races of men _palaeocosmic_, and the later _neocosmic_, where it may be necessary to refer to them _as races_; while the _periods_ to which they belong are respectively the _Palanthropic_ and _Neanthropic_. By the use of these terms all ambiguity will be avoided.

CHAPTER II

THE WORLD BEFORE MAN

Man is of recent introduction on the earth. For millions of years the slow process of world-making had been going on, with reference to physical structure and to the lower grades of living creatures. Only within a few thousand years does our globe seem to have been fitted for its highest tenant. The evidence of this is to be found in any text-book of geology. I propose here merely to present the history of the earth in a series of word-pictures, introductory to our special subject.

Our first picture may be that of a nebula, vast and vaporous, containing the mixed and unconsolidated materials of the sun and planets--a void and desolate ma.s.s, slowly aggregating itself under the influence of gravitation.

Our next may be that of an incandescent globe, molten and glowing, and surrounded by a vast vaporous envelope, but tending by degrees to a condition in which it shall have a solid crust, on which the greater part of the watery vapour suspended in its atmosphere is to be condensed into a heated ocean.

Our third picture may represent the world of what geologists call the archaean, or eozoic period, when the crust had been furrowed up into ridges of land, and corresponding but wider depressions occupied by the sea. Into the latter the rains falling on the land are carrying sediment derived from the wasting rocks, though the waters are still warm and the thinner parts of the crust are still welling out rocky material, either molten or dissolved in heated water. In this period there were probably low forms of animal life in the waters and plants on the land, though we know little of their exact nature.

A fourth picture may represent that great and long-continued palaeozoic period in which the waters swarmed with many forms of life, when fishes were introduced into the sea, and when the land became covered with dense forests of plants allied to the modern club-mosses, ferns, mares'-tails and pines; while insects, scorpions and snails, and some of the humbler forms of reptiles, found place on the land.

Returning after an interval, we should see a fifth picture, that of the mesozoic world. This was the age of reptiles, when animals of that cla.s.s attained their highest and most gigantic forms, and occupied in the sea, on the land, and in the air the places now held by the mammals and the birds; while the continents were covered with a flora distinct alike from that of the previous and succeeding periods, replaced, however, as time went on by forests very like those of the modern world. In this age the earliest mammals or ordinary quadrupeds were introduced, few at first, small and of low rank in their cla.s.s. Birds also made their appearance, and toward the close of the period fishes of modern types swarmed for the first time in the sea.

Lastly, we might see in the cenozoic, or tertiary age, the newest of all, quadrupeds dominant on the land and modern types of animal life in the sea. In this period our continents finally a.s.sumed their present forms. Toward its close and after many vicissitudes of geography and climate, and several successive dynasties of mammalian life, man and the land animals now his contemporaries occupied the world, and thus the cenozoic pa.s.ses into the _anthropic_, or modern period, called by some, but without good reason, 'quaternary,' since it is in all respects a proper continuation of the tertiary, or cenozoic.[3]

[3] It will be seen that our six pictures are in some degree parallel with the 'days' of creation. This is not an intentional reconciliation.

It merely expresses the fact of the case, whatever its significance.

This last age of the world is so intimately connected with man that it will be necessary to consider it more in detail. More particularly we may endeavour to answer, if we can, the questions of order and time involved in man's late appearance.

No geologist would expect to find any remains of man or his works in the periods represented by our five earlier pictures, because in these periods the physical conditions necessary to man and the animals nearest to him in structure do not appear to have existed, and their places in nature were occupied by lower types.

Nor for similar reasons would we expect to meet with man in the earlier part of that last, or cenozoic, period in which we still live; and in point of fact it is only in superficial deposits of the later part of this last great period of the earth's history that we actually meet with evidence of the existence of the human species.

If there is based on this fact a question as to the actual date of man's first appearance, the physical considerations indicate about twenty millions of years for the whole duration of the earth. Setting apart, say, a fourth of this time for the early pre-geologic condition of the world, the remainder may be roughly estimated as five millions for the archaean, or eozoic, six for the palaeozoic, three for the mesozoic, and one for the cenozoic.[4] Of the last, the later part, in which there is a possibility of the existence of man, will be limited to less than a quarter of a million; and within this the certainly known remains of man, whether attributed as by some to the latest inter-*glacial period, or to the post-glacial--a mere question of terms, and not of facts--cannot be older, according to the best geological estimates, than from seven thousand to ten thousand years. This, according to our present knowledge, is the maximum date of the oldest traces of man, and probably these are nearer in age to the smaller than to the larger number.

[4] The absolute length of these periods is, of course, a matter of estimation; but the _relative_ lengths of the different ages may be regarded as a fair approximation, based on facts.

If the reader will take the trouble to draw on paper a scale of twenty inches, each of these will represent a million of years of the earth's history, and the known duration of the human period may be indicated by a thickish line at one end of the scale. We may thus represent to the eye the recency of man's appearance, so far as at present known to science.

It may be said that all this is mere a.s.sertion. It fairly represents, however, the conclusions reached on the latest geological evidence, though this evidence would demand for its full detail a larger s.p.a.ce than the whole of this little volume. References are given below to works in which this evidence will be found.[5]

[5] Lyell's _Students' Manual_; Dana's _Manual_; Prestwich's _Geology_; _The Story of the Earth_, by the author.

It may also be objected that if, as held by some evolutionists, man was slowly developed from lower animals, and if his earliest known remains are still human in their characters, he must have had a vastly longer history covering the periods of his gradual change from, say, ape-like forms. This is admitted; but then we have as yet no good evidence that man was so developed, and no remains of intermediate forms are yet known to science. Even should some animal, either recent or fossil, be discovered intermediate in structure between man and the highest apes, we should still require proof that it was the ancestor of man, by the occurrence of connecting forms, or otherwise. As the facts now stand, the earliest known remains of man are _still human_, and tell us nothing as to previous stages of development.

We must now glance a little more particularly at what may be termed the more immediate antecedents of man. The latest great period of the earth's geological history (the cenozoic) was ingeniously subdivided by Lyell, on the ground of the percentages of extinct and surviving species of marine sh.e.l.ls contained in its several beds. According to this method, which, with some modifications in detail, is still accepted, the eocene age, or that of the dawn of the recent, includes those formations in which the percentage of modern or still living species of marine animals does not exceed three and a half, all the other species found being extinct. The miocene (less recent) includes beds in which the percentage of living species does not exceed thirty-five. The pliocene (more recent) includes beds in which the living forms of marine life exceed thirty-five per cent, but there is still a considerable proportion of extinct species. Newer than this we have the pleistocene (most recent), in which there are scarcely as many extinct species as there are of recent in the eocene. Lastly, the modern, of course, includes only the living species of the modern seas. Other geologists, notably Dawkins and Gandry, have arrived at similar results from a consideration of the vertebrate animals of the land. In the eocene we find numerous remains of mammals, or ordinary land quadrupeds, but all are extinct, and nearly all belong to extinct genera. In the miocene there are many living genera, but no species that survive to the present time. The pliocene begins to show a few living species, and these are dominant in the succeeding pleistocene.

These several stages of the cenozoic were also characterised by great vicissitudes of geography and climate. In the early and middle portions of the eocene, much of the land of the northern hemisphere was under the sea or in the state of swamps and marshes, and there seems to have been a very mild and equable climate, insomuch that plants now limited to warm temperate regions could flourish in Greenland. It is further to be observed that regions such as Mesopotamia, Syria and Egypt, which are known to us historically as among the earliest abodes of man, were at this time under the ocean, as were also rocks that now appear at great elevations in the highest mountains of Europe and Asia. For example, the limestones through which the Nile has cut its valley are marine beds of eocene age, and beds of the same period holding marine remains occur at an elevation of 16,000 feet in the Himalayan region.

In the miocene the amount of land was somewhat greater, though large areas of the continents were still under the sea, and the climate was still mild, but for reasons to be stated in the sequel it is not likely that man inhabited the warm continents of this age. The pliocene inaugurates what has been termed a continental period, when the land of the northern hemisphere was higher and more extensive than at present.

It was also a time of great physical change, when much erosion of valleys and sculpturing of the surface of the land occurred, and when extensive earth movements and ejections of igneous rock increased the irregularity of the surface and gave greater variety and beauty to the land. The pliocene was altogether a most important period for giving the finis.h.i.+ng touches of physical geography, and in it several modern species of land animals were introduced; but we have as yet, as we shall find in the sequel, no certain evidence that man was a witness of the movements and sculpturing of the earth's crust, so important in the preparation of his future home, though statements to this effect have been made on grounds which we shall have to consider.

In the course of the pliocene the previously high temperature of the northern hemisphere was sensibly lowered, and at its close the pleistocene period introduced a cold and wintry climate, along with gradual and unequal subsidence of the land, the whole producing that most dismal of the geological ages, known as the 'glacial period.' At this time much of the lower land of the continents was submerged and the mountains became covered with snow and ice, leaving s.p.a.ce for vegetable and animal life only toward the south and in a few favoured spots in the higher lat.i.tudes. There is much difference of opinion among geologists as to the extent, duration and vicissitudes of this reign of ice, but there can be no doubt that it destroyed much of the animal and vegetable life of the pliocene, or obliged it to migrate to the southward. In this period great deposits of mud, sand and gravel were laid down, which prepared the world for a new departure in the succeeding age. This we may name the post-glacial, or early modern period, and in it we have the most certain evidence of the existence of man, though the geographical arrangement of our continents and their animal inhabitants were in many respects different from what they now are. If geologists are right in the conclusion already stated, that the close of the glacial period is as recent as 7,000 years ago, this will give us a narrow limit in time for the age of man, at least under his present conditions.

While, however, there is an absolute consensus of opinion among geologists as to the existence of man at or about the close of the glacial age, in the northern temperate regions at least, there are some facts which have been supposed to indicate a pre-glacial human period, or the advent of man even as early as the middle of the cenozoic time.

These merit a short consideration.