CHAPTER VII

EXTINCT SPECIES

Let us now test the value of this assumed 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 classed 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 classifying off the Tertiary and post-Tertiary beds. Those with all the species extinct, or less than 5 per cent. living, are classed as Eocene; those containing =few= extinct forms, or nearly all living species, are classed 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 assigned 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 assumption 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 assuming 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.

And the completely worthless character of such "evidence" of age becomes, if possible, more apparent when we consider that very many of these so-called "extinct" forms are not really distinct species from their living representatives of to-day. "It is notorious," says Darwin, "on what excessively slight differences many palaeontologists have founded their species." And even to-day, in spite of all that we have learned about variation, little or no allowance seems ever to be made for the effects of a certainly greatly changed environment. If the fossil forms among the mollusks and other shell fish for instance, are not precisely like the modern ones in every respect, they are always classed as separate species, the older forms thus being "extinct," in utter disregard of the striking anatomical differences between the huge Pleistocene mammals and their dwarfish descendants of to-day, which for a hundred years or so were declared positively to be distinct from one another, but are now acknowledged to be identical.

Of course no one denies that there are numerous extinct forms among the invertebrates, just as we know there are among the huge vertebrates of the Mesozoic and Tertiaries, none of which we moderns have ever seen alive. Other forms do not appear familiar to our modern eyes, because larger or of somewhat different form; but to say that they are really distinct species from their modern representatives, or to say that no human being ever saw them alive, are statements utterly incapable of proof. Up to about the year 1869 it was stoutly maintained that man had never seen =any= of these fossil forms in life. But no one now maintains this view, for human remains have now been found along with undisturbed fossils of the Pleistocene, or even middle Tertiaries, while the paintings on the cave walls of Southern France seem conclusive that they were copied from life when the mammoth and reindeer lived side by side with man in that latitude. Hence the only question now is, and it is the supreme question of all modern geology, =WITH HOW MUCH OF THAT ANCIENT FOSSIL WORLD WERE THESE EQUALLY FOSSIL MEN ACQUAINTED?= If Man lived in "Pliocene" or perhaps "Miocene times," when a luxuriant vegetation was spread out over all the Arctic regions, what possible evidence is there to show that his companions, the rhinoceros, hippopotamus, mammoth, etc., were not also living then and browsing off just such plants, when the Arctic frosts caught them in the grip of death and put their "mummies" in cold storage for our astonishment and scientific information? Things which are equal to the same thing are equal to each other; why should not the plants and animals, contemporary with the same creature (man), be just as truly contemporary with one another? If man was contemporary with the Miocene plants, and the Pleistocene mammals were contemporary with man, what is there to forbid the idea that the Pleistocene mammals and the middle Tertiary flora were contemporary with each other?

For nearly half a century geologists have never had the courage to face this problem fairly and squarely, with all preconceived prejudices about uniformity cast aside. Is it possible that all the plants and animals of the Tertiaries and the Pleistocene may have really lived together in the same world after all? But the trouble would then be that, with this much conceded, the whole "phylogenic series" would tumble with it, and become only the taxonomic or classification series of that ancient world with which these fossil men were acquainted. To appropriate the words of one who has done much to clear the ground for a common-sense study of geology, I know of nothing against such an idea save "the almost pathetic devotion of a large school of thinkers to the religion founded by Hutton, whose high priest was Lyell, and which in essence is based on _a priori_ arguments like those which dominated Mediaeval scholasticism and made it so barren."[36]

Baron Cuvier's work in the line of comparative osteology has never been surpassed, perhaps never equalled since, and he is said to have been "the greatest naturalist and comparative anatomist of that, or perhaps of any time." (LeConte, "Evol. and Rel. Thought," pp. 33, 34); and yet he maintained till the last that all those which we now call the Pleistocene mammals were distinct species from the modern ones; and it is only of recent years and with extreme reluctance that many of them have been admitted to be identical with the ones now living. All of which tends to show how unreliable are those assertions commonly found in the text-books about all the species of the so-called "older" rocks being extinct. It is only with hesitation that such specific distinctions are surrendered even to-day, though during the last few decades a steady progress has been made in bringing the palaeontology of the higher vertebrates into line with our increased knowledge of zoology, thus breaking down many of the specific distinctions which have long been maintained between the fossil and the living forms. Even the mammoth has been found to have so many characters identical with the modern elephant of India, and such a complete gradation exists between the two types, that Flower and Lydekker acknowledge the transition from one to the other is "almost imperceptible," and express a doubt whether they "can be specifically distinguished" from one another.[37]

But the extreme reluctance with which anything like a confession of this fact leaks out in our modern literature can be readily understood when we try the hopeless task of splicing the environment of the modern form with that of the ancient on any basis of uniformity.

Zittel gives us a peep behind the scenes which helps us to appreciate the value of a percentage of extinct species as a test of the age of a rock deposit.

He pictures the uncritical work of the earlier writers on fossil botany, until August Schink (1868-91) made a great reform in this science; and Zittel declares that "now the author of a paper on any department" of fossil botany "is expected to have a sound knowledge" of the systematic botany of recent forms. But he adds: "It cannot be said that palaeozoology (the science of fossil animals) has yet arrived at this desirable standpoint."

But he justifies this charge of want of confidence by saying:

"Comparatively few individuals have such a thorough grasp of zoological and geological knowledge as to enable them to treat palaeontological researches worthily, and there has accumulated a dead weight of stratigraphical-palaeontological literature wherein the fossil remains of animals are named and pigeon-holed solely as an additional ticket of the age of a rock-deposit, with a willful disregard of the much more difficult problem of their relationships in the long chain of existence.

"The terminology which has been introduced in the innumerable monographs of special fossil faunas in the majority of cases makes only the slenderest pretext of any connection with recent systematic zoology; if there is a difficulty, then stratigraphical arguments are made the basis of a solution. Zoological students are, as a rule, too actively engaged and keenly interested in building up new observations to attempt to spell through the arbitrary palaeontological conclusions arrived at by many stratigraphers, or to revise their labors from a zoological point of view."[38]

Doubtless this scathing impeachment of the common mania for creating new names for the fossils has especial reference to the case of the lower forms of life. For if, in spite of the brilliant and withal careful work of Cuvier, Owen, Wallace, Huxley, Ray Lankester, and Leith Adams, with numerous others that might be mentioned, there are still grounds for such grave doubts of the values of specific distinctions in the case of the mammals, whose general anatomy and life-history are so well known and their almost countless variations so well studied out, =what must be the confusion and inaccuracy= in the case of the lower vertebrates, and especially of the invertebrates, whose general life-history in so many instances is so dimly understood, and the limits of their variations absolutely unknown? Remembering all this, what is our amazement when we read in this same volume by Professor Zittel[39] that the tendency among many modern writers in dealing with these lower forms of life, is toward the erection of the closest possible distinctions between genera and species, until recent palaeontological literature is fairly inundated with new names; and all this with =the purpose=, unblushingly avowed, of "enhancing the value" of such distinctions as a means of determining the relative ages of strata, and to "bring the ontogenetic and phylogenetic development" of the various forms "into more =apparent= correspondence." I do not exaggerate in the least, as the reader may see by referring to Zittel's book; though not wishing to make my readers "spell through" another quite technical paragraph I have refrained from direct quotation.

But surely we have here a most amazing style of reasoning. It is another clear case of first assuming one's premises, and then proving them by means of one's conclusion. The method here employed seems about like this: First assume the succession of life from the low to the high as a whole; then in any particular group, as of Brachiopods or Mollusks, decide the momentous question as to which came first and which later in "geological time" by comparing them as to size, shape, etc., with the live modern individual in its development from the egg to maturity; and lastly, =take the results= of this alleged chronological arrangement to prove just =how= the modern forms have evolved. Surely it is a most fearful example of otherwise intelligent men being hypnotized by their theory into blind obedience to its suggestions and necessities.

Not long ago I had occasion to write to a well-known geologist about a Lower Cambrian mollusk which appears strikingly like a modern species. I give below an extract from his reply which bears directly upon this point. I withhold the name, for the information was given in a half-confidential manner, but I may say that the author's work on the Palaeozoic fossils is recognized on both sides of the Atlantic.

"Some geologists make it a point to =give a new name= to all forms found in the Palaeozoic rocks, i.e. a name different from those of modern species. I was taken to task by a noted palaeontologist for finding a pupa (a kind of land snail) in Devonian beds; but I could not find any point in which it differed from the modern genus [? species]. Yet if I could have had more perfect specimens I might have found differences."

Such disclosures speak volumes for those able to understand; and lead one to receive with a smile the familiar assertion that all the species of the Palaeozoic and other "older" rocks are extinct. And we can now form a truer estimate of the high scientific accuracy of Lyell's ingenious division of the Tertiary beds, according to the percentage of living or extinct Mollusks which they contain.

But from the inherent weakness of the argument about extinct species as thus revealed, it follows that chronological distinctions based on any proportionate number of extinct species =have absolutely no scientific value=; and hence that the life succession theory finds no support from these chronological distinctions, just as we have already seen that it is without a vestige of support from the stratigraphical argument.

The life succession theory has not a single fact to confirm it in the realm of nature. It is not the result of scientific research, but purely the product of the imagination.

FOOTNOTES:

[33] See p. 39 of this volume.

[34] "Intro. Text-Book," p. 189.

[35] "Manual," p. 1007. Prof. Dana has italicized the word "=suddenly=."

[36] Howorth, "The Glacial Nightmare and the Flood," preface, xx, xxi.

[37] "Mammals, Living and Extinct," pp. 428-9.

[38] "Hist. of Geol.," pp. 375-6.

[39] pp. 400, 403, 405.