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.