Life: Its True Genesis

by Horatius Flaccus

From the fossilized plants of Atanekerdluk--a flora rich in species and wonderfully preserved in type--and the Miocene flora of Spitzenburg, to the southernmost limits of vegetation on the globe, science has reached out her hands for materials, and gathered them with as much success as avidity. And all scientific botanists agree in referring these fossilized forms from the high northern latitudes, to the Miocene period--one so remote that we can form no adequate conception of it, except as time may be measured by geologic periods. And these materials show that varieties of the Sequoia, the tulip-tree, oaks, beeches, walnuts, firs, poplars, hazelnuts, etc., etc., all flourished in these sub-arctic regions during the far-distant period we have named. Many of them must have grown on the spot where their trunks are now to be found, as their roots remain undisturbed in the soil, as well as at a time when these regions enjoyed a warm or cold temperate climate. Many of these fossilized and carbonized forms are identical with the living species of to-day, conclusively showing that neither natural variation, nor any secondary causes, have worked out any changes capable of being scientifically expressed in genetic value.

There is also abundant evidence to show that many of the present tropical forms flourished in central and southern Europe as far back as the warm inter-glacial epoch in the Eocene period. And if these inter-glacial periods occurred at the lowest minimum limits of eccentricity in the earth's orbit, as calculated by Leverrier's formulæ, we can have no conception whatever of the length of time actually intervening the period named and our present era. Mr. Croll has given us the limits of highest glaciation covering the last three million years, and shows that there have been but two periods of superior eccentricity in that time, and can be only one in the next million years, with but two or three intervening maxima and minima that may, or may not have been, of any special value. It is true that he assigns importance to these maxima, as affecting possible glaciations, but there are other eminent astronomers and physicists who differ from him, and really attach little or no importance to these of any other intervening periods of eccentricity. If Mr. Croll is correct in his theory and estimates, we must separate these superior glacial epochs by an interval of not less than one million seven hundred thousand years; and nearly three of these periods must have intervened since some of the present tropical forms flourished in Europe. And if these forms have undergone no specific change in all this time, how many years will it require to work out even one of Mr. Darwin's many evolutional changes?

The kinship between some of these arctic and sub-arctic fossilized flora and the living forms of to-day, is so near that they cannot be distinguished by a single difference. This is true of some of the varieties of the Sequoia family, the oaks, beeches, firs, hazelnuts, etc., while others are so nearly identical that it would be difficult to classify them as separate varieties. At all events, if they cannot be placed in the list of identical species, they cannot be ruled out of representative types. But why should our speculative botanists insist upon these "evolutional changes" in plant-life--these "derivative forms" of which they are constantly speaking? Paleontological botany has given us the very highest antiquity of species, and the most that can be claimed is that nature was just as prolific of diversified forms millions of years ago as now. Because we, by forcing nature into unnatural, if not repugnant, alliances, can produce

--"Streak'd gillyflowers,
Which some call nature's bastards."

it is no evidence that she commits any such offence against herself. Her alliances are all loving ones. She indulges in no forced methods of propagation. If she produced the Sequoia gigantea, or the great redwood tree of our California Sierra, as far back as the Crustaceous period, she has propagated it ever since according to her own loving methods, and it is idle to talk of the Sequoia Langsdorfii as being the original ancestor of this tree, or any other distinguished branch of the sequoias. How much more rational the suggestion of Professor Agassiz that these trees--the entire family of sequoias--were quite as numerous in individual varieties at first as now, and that the fruit of the one can never bear the fruit of the other.

Again, take the still hardier and more numerous branches of the Quercus or oak family. M. De Candolle has expended a vast deal of ingenuity to show that the various members of this old and ancestrally-knotty family have all descended from two or three of the hardier varieties. He arrives at this conclusion from a geographical survey of what he would call the "whole field of distribution," and "the probable historical connection between these congeneric species." But science should deal with as few probabilities as possible, especially where experience furnishes no guide to certainty, and only the remotest clue to likelihood. We should never predicate probabilities except on some degree of actual evidence, or some likelihood of occurrence, falling within the limits, analogically or otherwise, of human observation and experience. In no other way can we determine whether an event is probable or not. But here we have not so much as a probable experience to guide us. Geographical distribution in the past is hardly a safe criterion to go by, because we can never be absolutely certain that we have the requisite data on which to form a determinate judgment. The Quercus robur may furnish the maximum test to-day, but a few concealed pockets of nature may bring some other variety of the congeneric species to the front to-morrow, requiring M. De Candolle to correct his classification. There are no less than twenty-eight varieties of this one species of oak, all of them conceded to be spontaneous in origin, and it has been on the earth quite as long as the more stately tribe of Sequoias. Besides, not more than one twenty-thousandth part of the earth's surface has been dug over to determine the extent to which any one of its varieties has flourished in the past.

Since these several varieties are only one degree removed from each other, M. De Candolle supposes divergence to be the natural law which has governed their growth, and not hereditary fixity. But here again he has only remote probabilities to work upon, no absolute data. We are still speaking of his fossilized herbaria, not his modern specimens. These may show a large number of genetically-connected individuals, or those claimed to be so connected. And yet no naturalist can be certain that, because they exhibit similarly marked characteristics, the one ever descended from the other; for the universal experience-rule still holds good that "like engenders like," and we search in vain for anything more than a similarity of idea, or logical connection, which justifies a recognition of the individuorum similium in Jessieu's definition of species. But similarity must not be mistaken for absolute likeness, which nowhere exists in nature. Infinite diversity is the law, absolute identity the rarest possible exception. No two oak leaves, for instance, in a million will be found actually alike, although taken from the same tree, or trees of the same variety; and the same may be said of the segmentation and branching of their limbs, as well as the striatures of their corticated covering, Et sic de similibus everywhere, and with respect to every thing. Nature is more solicitous of diversity and beauty, than of similarity and tameness of effect, in all her landscape pictures; and the Platonic conception that "contraries spring from contraries," may be only a supplementary truth to that of de similibus. In the eye of the soul all objective existences are discerned in their logical order, or as consecutive thoughts of the Divine mind, as outspoken in the material universe. To insist upon cutting down these transcendental forms[[20]] into the smallest possible number of similar or identical forms, may be all well enough to accomplish scientific classification; but the productive power of nature can never be limited by these mental processes of our own.

The oak family can be traced back to the Miocene period, and consequently enjoys quite as high an antiquity as the sequoias. Professor Gray, in speaking of the Quercus robur and its probable origin, says that it is "traceable in Europe up to the commencement of the present epoch, looks eastward, and far into the past on far-distant shores." By "far-distant shores," he undoubtedly means Northwest America, where its remotest descendants still flourish. But that these trees should have waded the Pacific, or sent their acorns on a voyage of discovery after new habitats on the Asiatic coast, is hardly more probable than Jason's voyage after the golden fleece, in any other than a highly figurative sense. The spontaneous appearance of a forest of oaks on the eastern shores of Asia was just as probable, under favoring conditions--though occurring subsequently to the time of their appearance on this continent--as that of the miniature forests of "samphire," or small saline plants, which spontaneously made their appearance about the salt-works of Syracuse, when conditions actually favored. The high antiquity of the oak makes no difference in respect to the principle of dispersion, since geographical conditions are what govern, and not the theoretical considerations of the speculative botanist.

Mr. A. R. Wallace's formula concerning the origin of species, that they "have come into existence coincident both in time and place with preëxisting closely-allied species," may or may not be true so far as individual localization is concerned. But it proves nothing in the way of original progeny, nor can we, by any actual data before us, satisfactorily determine, under this formula, which of the two closely-allied species preceded the other. If they came coincidently, both in time and place, their existence must have been concurrent, not separated by preëxistence. The formula may be true to this extent, that the conditions favoring the appearance of one species may have equally favored what we call a closely-allied species. But even in this case, the material sequence is lost, and we have nothing to express a relationship as from parent to progeny. For, however restricted as to localization, each species preserves its own characteristics, the similarities always being less than the dissimilarities. These, and other equally conclusive facts of observation, led Professor Agassiz to question any necessary genetic connection between the different species, or between even the same species, in widely-separated localities; his idea being precisely that advanced by us in connection with the Bible genesis, that localization depended on geographical conditions, not on the migration of plants or the dispersion of seeds.

The actual geographical distribution of species--any species--does not depend solely on lines of ancestry, however great their persistence of specific characters; nor on any principle of natural selection, nor on the possibility of fertile monstrosities, but on the simple incidence of conditions; and M. De Candolle, in his "Geographie Botanique," virtually concedes this, while treating of geographical considerations in connection with distribution. He in fact says, in so many words, that the actual distribution of species in the past "seems to have been a consequence of preceding conditions." [[21]] And he is forced to this conclusion by his virtual abandonment of plant-migration, and the alleged means of seed-distribution.