[27] "Annual Report," New Series, Vol. II., Part D, pp. 33-34.
[28] pp. 111, 534.
[29] Nov. 13, 1884, pp. 29-35.
[30] See _Nature_, Jan. 24, 1901, p. 294.
[31] "Text-Book," p. 678.
CHAPTER VI
FACT NUMBER FOUR
There is only one cla.s.s of agents now working upon the rocks of the globe which have been in business continuously ever since the dry land appeared, and which have left us a legible record of approximately the amount of business they have been doing all these centuries. And my Fact Number Four, which will complete this line of argument in ill.u.s.trating the antagonism between the facts of the rocks and the theory of life succession, is that the =rivers= of the world, which of course are the agents to which I have referred, in traveling across the country, =act precisely as if they knew nothing of the varying ages of the rocks=, but on the contrary treat them all alike as if they were of the same age, and =as if they began sawing at them all at the same time=. Of course it is, evidently, in only a few cases where the records are so free from ambiguity as to be quite incapable of being misunderstood, that is, the cases of rivers with steep rocky gorges, or those that cut through mountain ranges; but there are several such rivers in the world, and they all seem to tell the same story.
The famous Colorado River is a good example. It flows from "younger"
strata into "older" in its deep cutting across the Arizona plateau.[32]
Stated in terms of the current theory, this means that when the region of country about the lower part of this river"s course first became dry land, the upper part was still sea, and that thus there was no such river in existence here until the very "youngest" of these rocks was formed. For otherwise the river must have started running from the sea toward the dry land, i.e., running up hill. Stated in terms neutral as to theory, it means that the whole of this region of country, drained by this large river, with its rocks of many varying "ages," was all elevated practically as it is now before this river began its work of erosion. It treats all these rocks as if they were of the same age, and as if it began sawing at them all at the same time.
Also its companion, the Green River, cuts through the Uinta Range in the same manner. Similar conditions are said to occur on the Danube, and in the river-courses of the Himalayas, and elsewhere.
In the case of the Colorado, Zittel says that:
"Powell"s explanation of the apparent enigma is that after the river had eroded its channel rocks were uplifted in one portion of its course, but so slow was the rate of uplift that the river was enabled to deepen its channel, either proportionately or more rapidly, so that it was never diverted from its former course."
It was by similarly cunning inventions that the early writers on astronomy, alchemy, and medicine evaded the force of acc.u.mulated facts which told against their absurd theories.
We have now completed our survey of the strictly stratigraphical phases of this question, and have found four very remarkable principles about the rocks, which I wish to summarize here before proceeding further.
(1) The "broad fact," as stated by Zittel and Dana, that any kind of rocks whatever, i.e. containing any kinds of fossils, even the "youngest," may rest on the Archaean, and may thus in position, as also in texture and appearance, resemble the very oldest deposits on the globe.
(2) That any kind of beds may rest in such perfect conformability on any other so-called "older" beds over vast stretches of country that, "were it not for fossil evidence, one would naturally suppose that a single formation was being dealt with," while "the vast interval of time intervening is unrepresented either by deposition or erosion." The youngest seem to have followed the oldest in quick succession.
(3) That in very many cases and over many square miles of country these conditions are exactly reversed, and such very "ancient" rocks as Cambrian limestones are on top of the comparatively "young" Cretaceous, while the lime between them "acts exactly like the line of contact of two nearly horizontal formations," and in a natural section made by a river the two "appear to succeed one another conformably." To any one ignorant of the theory of life succession they have every appearance of having been deposited as we find them.
(4) That the rivers of the world, in cutting across the country, completely ignore the varying ages of the rocks in the different parts of their courses, and act precisely as if they began sawing at them all at the same time.
Now I know not what additional fact can be demanded or imagined to complete the demonstration that there is =no particular order= in which the fossils can be said to occur as regards succession in time. It is true, some fossiliferous deposits, metamorphosed almost beyond recognition, and buried deep beneath thousands of feet of subsequent deposits, have enough appearance of remote antiquity about them in all conscience. But to increase this antiquity by saying that other equally prodigious ma.s.ses of rocks elsewhere were deposited long after these, or by pointing to still other deposits in another region which are said to be older than any of the others, is an illogical and wholly unscientific procedure. I fear I could scarcely confine myself within the bounds of parliamentary language were I to attempt to express an opinion regarding any effort that may now be made to justify the life succession theory in view of the above acknowledged facts.
And surely it is scarcely necessary in this enlightened age to point out how completely this vitiates any biological argument (such as that of Darwinism) which has incorporated into its system the results of such illogical reasoning, or which in any way is dependent upon the conclusions of such a theory of geology. In view of the laws of evidence, which every intelligent person is supposed to understand now-a-days, surely some strange things pa.s.sed for scientific proof during the nineteenth century. For, as we have seen, the earlier geologists did little better than =a.s.sume= the succession of life bodily; than Aga.s.siz and his contemporaries =arranged the details= and the exact order of these successive life forms by comparison with the embryonic life of the modern individual; and now the evolutionists of our day, led by such men as Spencer and Haeckel with their "phylogenetic principle," =prove their theory of evolution= by showing that the embryonic life of the modern individual is only "a brief recapitulation, as it were, from memory," of the (a.s.sumed) geological succession in time. Surely this will some day make a more amazing record for posterity than those of phlogiston or the epicycles of Ptolemy.
If I am now asked: What do the rocks have to tell us, in view of the fact that they refuse to testify to a life succession? I can only say that we are not as yet in a position to decide this question. There are several other matters connected with the character and mode of occurrence of the fossils, which are almost equally important with anything already considered, in forming a true scientific induction regarding this matter. These facts must be considered in subsequent chapters. Already, however, we can say this much, that we have in the rocks almost as complete a world, in some respects vastly more complete, than the living world of to-day. With the life succession theory repudiated, we have still to deal with the fossils themselves which have been thus systematically cla.s.sified; =but this geological series becomes only the taxonomic or cla.s.sification series of an older state of our present world=, buried somehow and at some time or times in the remote past--the how and the when of which we have not as yet the means to determine.
But I think we are now prepared to enter the mazes of the biological argument, and to study the subject of extinct species, which by many is supposed to furnish a line of independent evidence in favor of the life succession theory.
FOOTNOTE:
[32] See Zittel, "History of Geol.," pp. 210, 211.
CHAPTER VII
EXTINCT SPECIES
Let us now test the value of this a.s.sumed life succession by another very simple question. In "Eocene times," so we are told, England was a land of palms, with a semi-tropical flora and fauna. In fact at this time, cycads, gourds, proteads (like the Australian shrubs and trees), the fig, cinnamon, screw-pine, and various species of acacias and palms, abounded in England and Western Europe; while turtles, monkeys, crocodiles, and other sub-tropical and warm-temperate forms were equally abundant. Then again, in the Pleistocene deposits of the same countries, we find various species of elephant and rhinoceros, with a hippopotamus, lion, and hyena, identical with species now living in the tropics, "although," as Dana says, "these modern kinds are dwarfs in comparison."
=Now, how are we to prove that these various forms of animal life did not exist together in these countries at the same time as the trees and plants before mentioned?=
Lions and monkeys, hippopotami and crocodiles, with elephants, hyenas, and rhinoceroses, now live beneath the palms, mimosas, acacias, and other tropical plants represented in the Eocene and Miocene beds. What is there to hinder us from believing that they all lived there together in that olden time? Surely it would be the very irony of scientific fate if forms now so closely connected in life should in death be so divided.
Or, to present it in another form, why should we be asked to believe that these acacias, cinnamons, palms, etc., lived and died ages or millions of years before the lions, elephants, rhinoceroses and hippopotami, came into existence to enjoy their shade; and then, after these unnumbered ages had dragged their slow length along and vanished into the dim past, and all these semi-tropical plants had shifted to the tropics or been turned into lignite, these lions, elephants, and hippopotami came into existence in these same localities, when no such plants existed anywhere in Europe?
Surely we ought to expect some pretty substantial evidence for such a violation of "the observed uniformity of nature." We generally boast that we have outgrown the crude ideas of the earlier years of the science when they spoke of "ages" of limestone making or of sandstone making; but it seems that some of us have not yet attained to that broad view of the essential =unity of nature= in which the flora and fauna of our world are seen to be just as indissolubly connected with each other.
But nature could as easily be persuaded to produce for a whole age nothing in the way of rock but limestone or conglomerate, as to adjust her powers to such an unbalanced state of affairs as is spoken of above, with the animals in one age and the complementary plants in another.
But in considering this question as to why the Eocene plants and the Pleistocene animals may not be supposed to have lived contemporaneously together, we are brought face to face with the =second= supposed argument in favor of there having been a succession of life on the globe. The answer given is that all the animals of these "early"
Tertiary beds are extinct species, also very many of the plants; while the hyena, lion, hippopotamus, etc., of the Pleistocene are identical with the living species, and even the mammoth is so closely like its nearest surviving relative, the Asiatic elephant (_E. indicus_), that these also might be cla.s.sed as identical.[33]
This point being considered by many as so important, and having such a vital connection with the whole life succession theory, we must go into the matter somewhat in detail, even at the risk of appearing rather technical to some.
If the Palaeozoic and Mesozoic strata are often of enormous extent, spreading in vast sheets over wide regions, so that their stratigraphical order in any particular district is quite readily made out, it is in =most cases= altogether different with the Tertiary and Pleistocene deposits. For these resemble one another so much in everything except their fossils, and occur so generally in detached and fragmentary beds, holding no stratigraphical relation to one another, that Lyell devised the plan of distinguishing them from one another and arranging them in the accustomed order of successive ages, by their relative percentages of living and extinct mollusca. With only unimportant changes, Lyell"s divisions are still followed in cla.s.sifying off the Tertiary and post-Tertiary beds. Those with all the species extinct, or less than 5 per cent. living, are cla.s.sed as Eocene; those containing =few= extinct forms, or nearly all living species, are cla.s.sed as Pleistocene or post-Tertiary. The Miocene and Pliocene represent the intermediate grades, and all are supposed to be a true chronological order. It goes without saying that in actual practice it is often so extremely difficult to adjust these differences that beds are a.s.signed to an "early" or a "late" division on =general principles= by what the literary critics would call "tact" or "intuition," rather than by the strict percentage system, though for these large and important divisions of Tertiary and post-Tertiary rocks, these are absolutely the only professed grounds on which the subdivisions are distinguished and arranged in the customary order of time.
In the words of Dr. David Page:
"As there is often no perceptible mineral distinction between many clays, sands and gravels, it is only by their imbedded fossils that geologists can determine their Tertiary or post-Tertiary character."[34]
Now to say that a set of beds, ninety-five per cent. of whose fossils belong to extinct species, and only five per cent. are now living, must be vastly older than another set where these percentages are reversed, i.e. where the species are nearly all living, seems at first thought an eminently reasonable idea, and we immediately begin to imagine the long ages it must have taken for these exceedingly numerous and apparently vigorous species to wear out and become extinct in the alleged ordinary way by the merciless struggle for existence with forms more fitted to survive.
But it is hardly necessary to point out that all this is based on the a.s.sumption of =Uniformity= in its most extreme type, a doctrine which not only denies that these living forms are merely the =lucky survivors= of tremendous changes in which their contemporaries perished, but which in essence is taking for granted beforehand the very point which ought to be the chief aim of all geological inquiry, viz., How did the geological changes take place? It would not be considered a very scientific procedure for a coroner, called upon to hold a _post mortem_, to content himself with interesting statistics about the percentage of people who die of old age, fever, and other causes, while there was clear and decisive evidence that the poor fellow had been =shot=. In this case, as in geology, it is not merely the result that is wrong, but the whole method of investigation. For, as in the latter case we don"t want to know how people generally die, but how this particular person actually did die, so, in our study of geology, we do not wish to know merely the rate at which changes of surface and extinctions of species are now going on, and then project this measure backward into the past as an infallible guide, but we wish to know for sure just what changes of this nature have taken place. A true induction is, I think, capable of deciding very positively whether or not the tools of nature have always worked at the same rate and with the same force as at present; and this method of arranging the fossils in supposed chronological order on the percentage basis mentioned above, is only an extreme form of methods claiming to be inductive which in this age of the world ought to be considered a shame and a disgrace, because, as Howorth says, they are based, "not upon induction, but upon hypotheses," and have "all the infirmity of the science of the Middle Ages."
Then again, it occurs to us, that this method, of attaching a time-value to percentages of extinct or living species, would make the sub-fossil remains of the bison on the Western prairies almost infinitely =older= than those of the lion, hippopotamus, etc., in the Pleistocene beds of Europe; for (except for some few specimens artificially preserved, and which may be ignored in this connection) the bison is to-day absolutely extinct, while the Pleistocene mammals are found by the thousand in the proper localities and show no signs of surrender in the struggle for existence. Similar comparisons might be made between the great wingless birds of Madagascar, Mauritius and New Zealand, and the many cases of "persistent" forms which have survived unchanged from Carboniferous, Silurian, or Cambrian times, a period of time which, in the language of the current geology, means quite a large fraction of eternity. But all of these considerations show that the mere fact of certain species being extinct and others being now alive, is no trustworthy guide in determining the relative age of their remains, until we first find out =how they happened to become extinct=.
The inquiry as to the =how= and the =when= (relatively) is an absolutely essential preliminary in any such investigation; and is inseparably united in nature with the general question of how the great geological changes have taken place in the past. Of course, if everything like a world-catastrophe is =a priori= denied; if, in other words, it is settled from the first that all these fossils living and extinct did not live contemporaneously with each other, the living ones being simply the lucky survivors of stupendous changes in which the others perished, then all pretense of a scientific investigation of the subject is at an end.
If a coroner has it settled beforehand that an accident or a murder could not possibly have occurred, then his profession of a candid _post mortem_ examination is only a farce; for he does not hold it to find out anything, since he knows everything essential about it beforehand.
Uniformitarians would certainly make poor coroners, or for that matter poor investigators of law or history, or anything else.
Will some one please give us a reasonable explanation of why the lion, hippopotamus, rhinoceros, and elephant shifted from England to the tropics? Or will they explain how, at this same general time, some elephants and rhinoceroses got caught in the merciless frosts of Northern Siberia so suddenly that their flesh has remained untainted all these centuries, and is now, wherever exposed, greedily devoured by the dogs and wolves?
An abundant warm-climate vegetation once mantled all the polar regions, and its fossils have been found just about as far north as explorers have ever gone; while Dana says that, "The encasing in ice of huge elephants, and the perfect preservation of the flesh, shows that the cold finally became =suddenly= extreme, as of a single winter"s night, and knew no relenting afterwards."[35]
Now, if no one can deny this =sudden= change of climate over half the world or so at least, is it not extremely unscientific to deny that this same cause, whatever it may have been, was quite competent to bring about a good many other changes, and the extinction of numerous other species which we are so often reminded must imply the lapse of untold ages of time? The economizing of energy, or the famous law of parsimony as stated by Leibnitz, is quite appropriate in this case, and may be referred to again in the sequel. The principle upon which I must here insist is that the mere fact of certain species being extinct, and others being now alive, gives no clue whatever to the relative age of these remains, until we first ascertain =why=, =how= and =when= this extinction was brought about. And yet, though every one admits the fact of tremendous changes of climate, etc., having intervened between that ancient world and our own (the true extent and character of which, as I have said, ought to be the chief point of all geological investigation), no allowance seems ever to be made for this as a powerful cause of extermination of all forms of life. But in the utter absence of any such explanation as to =how= and =when=, and in the very teeth of these facts a.s.suming a dead-level uniformitarianism, the presence of ten, fifty or a hundred per cent. of extinct forms in a set of beds is manifestly of no scientific value in determining age. It would be many degrees more reasonable and accurate to arrange all the Greek and Latin books of the world in chronological order according to the percentage of their =words= which have survived into the English language. Indeed, it would be much like a coroner, at the inquest following a railway disaster, attempting to arrange the exact order in which the various victims had perished by the proportionate number of surviving relatives which each had left behind him.