Popular Science Monthly/Volume 4/April 1874/Evolution and the Origin of Life
|EVOLUTION AND THE ORIGIN OF LIFE.|
By H. CHARLTON BASTIAN, M. D., F. R. S.
YEAR by year the word "Evolution" becomes diffused more widely through our literature, and the central idea which it implies grows familiar to an ever-increasing multitude of readers. We have witnessed within the last few years a marvelous awakening of interest in the minds of the public generally to questions of science, and it so happens that a discussion of the doctrine of Evolution has been more or less directly involved in those departments of Science and Philosophy which have during this period received the largest share of popular attention.
Perhaps the greatest impetus was given to the spread of the doctrine about fourteen years ago, by the publication of Mr. Darwin's now celebrated "Origin of Species." This volume has been followed by quite a library of works and memoirs on the same subject—partly scientific and partly popular. From about the same date also, Mr. Herbert Spencer has been engaged in systematically elaborating the principles of an all-comprehensive Evolution Philosophy, and the results of his genius and labor are now undoubtedly influencing the thoughts of a rapidly-widening circle of readers. Both in this country and abroad, the doctrine of Evolution is gradually but surely gaining ground among the most reflective; and, although many other writers have been more or less influential in determining this result, it has been in the main brought about by the two above mentioned.
Evolution implies continuity and uniformity. It teaches us to look upon events of all kinds as the products of continuously-operating causes—it recognizes no sudden breaks or causeless stoppages in the sequence of natural phenomena. It equally implies that natural events do not vary spontaneously. It is a philosophy which deals with natural phenomena in their widest sense; it embraces both the present and the far distant past. It seeks to assure us that the properties and tendencies now manifest in our surrounding world of things are in all respects similar to those which have existed in the past. Without a basis of this kind, the Evolution hypothesis would be a mere idle dream. Uniformity is for it an all-pervading necessity. Starting from facts of daily observation and from scientific experiments, the properties and tendencies of things are noted and grouped; while philosophers, using the knowledge thus gained, seek to trace back the progress of events and show how this complex world has gradually been derived from a world of more and more simple composition. We are taken back in imagination even much farther. We are referred to a primal haze or nebula––as the gigantic germ of a future Universe. This was the conception of Laplace.
But whether we follow the philosopher in his bold speculations concerning the past, or listen to the biologist making his predictions concerning the future stages which the germ of a given animal will pass through in the progress of its evolution—in each case the "uniformity of Nature" is tacitly assumed. This assumption underlies almost all our thoughts and actions, even in every-day life. And, without such a belief in the Uniformity of Nature, science would be impossible—the very idea of it, in fact, could never have arisen. In its absence we could neither fathom the past nor illumine the future. As Mr. Mill said—"Were we to suppose (what it is perfectly possible to imagine) that the present order of the universe were brought to an end, and that a chaos succeeded in which there was no fixed succession of events, and the past gave no assurance of the future, if a human being were miraculously kept alive to witness this change, he surely would soon cease to believe in any uniformity, the uniformity itself no longer existing."
It is true that in earlier times no absolute belief in the uniformity of Nature existed, even among the select few. The Greek philosophers, including Aristotle, recognized "chance" and "spontaneity" as finding a definite place in Nature, and to this extent they were not sure that the future would resemble the past. But as we have become more familiar with a wider range of natural phenomena, and with their mutual relations or order of appearance, so has the conception of chance or spontaneity disappeared from the scientific horizon—driven out of the field by the steady advance of Law and Order. Those who embrace the Evolution philosophy are foremost in this opinion—they believe that no effects of whatsoever kind can occur without adequate causes, and, the conditions being similar, that the same results will always follow the action of any given cause. Their whole creed is, in fact, preeminently based upon this assumed uniformity of Nature.
The present is essentially a time of transition in matters of opinion. Men who have been educated in one system of beliefs are gradually being converted to another, because the new system is thought to be more harmonious with the observed order of natural phenomena. This has been the case even with the chief exponents of Evolution. They have themselves had to unlearn much which they had previously learned. The doctrine of Evolution has thus been developed only by the sacrifice of many previous early beliefs and modes of thought. But it often happens that an old belief will—unknown, perhaps, to the person himself—leave decided traces of its previous influence, and thus prevent for a time the full realization of all the logical consequences of new views. This vestige of the old state of opinion or habit of thought is, more especially, apt to remain in directions where unexplained facts, or strong prepossessions and prejudices, bar the way. Some modes of this inconsistency may become obvious to one worker or thinker, and some to another, according to the particular direction which his investigations or thoughts may have taken; and such inconsistencies should be pointed out as they present themselves. So that, with the view of strengthening an hypothesis which I, in common with so many other workers in science, believe to be true, I now venture to allude to certain apparent anomalies in the declared opinions of the most prominent upholders of the doctrine of Evolution in this country. It seems all the more desirable that this should be done, since the inconsistencies may be easily shown to be wholly uncalled for, and to involve sundry unscientific conceptions. Yet the modifications of opinion which appear to be demanded, on the ground of fact as well as on the ground of reason, will necessitate very considerable and almost revolutionary changes in the accepted code of biological doctrines.
An examination of the facts of science generally and of various every-day phenomena teaches us, according to the Evolutionist, that matter of different kinds, situated as it is and has been, gradually tends within certain limits to become more and more complex in its internal and external constitution. Coupling this conclusion with various astronomical data, with geological data, and with facts derived from the study of the past forms of Life upon our globe, the Evolutionist essays to penetrate through the long vista of by-gone ages, till he may rest his speculative gaze upon a vast rotating nebular mass of gaseous matter, of comparatively simple though unknown constitution, from which he supposes our Universe to have been slowly evolved. Without futile questionings as to the explanation or cause of the existence of the nebula, without speculation as to what simpler or more complex matter may have immediately preceded it, it is obvious that we may for our own convenience take up its imaginary existence at any stage. Though we must be free to admit that in concentrating our attention upon this nebular stage, or upon any other, we arbitrarily break into a mysterious cycle of existence whose Cause is to us unfathomable. It is needless for my purpose, however, to attempt to concentrate the reader's attention upon a period so remote in the history of our Universe. The primordial nebula, as it cooled and condensed, acquired a more rapid axial rotation: masses were gradually thrown off from its circumference, and these in their turn condensed into rotating spheroids, which continued to circulate round the parent mass in elliptical orbits. Assuming, then, with the Evolutionist, that our own planet had a past history of this kind, we must also assume that it gradually changed from a gaseous to a fluid state before beginning to solidify by the formation of a superficial crust—a crust which gradually thickened as the fervent heat of it and of the fluid nucleus abated by heat-radiations into space. Until this stage of the Earth's history had been far advanced, no Living Things could have existed upon its surface. "Hence," as Sir William Thomson said, "when the Earth was first fit for life there were no living things on it. There were rocks, solid and disintegrated, water, air all round, warmed and illuminated by a brilliant sun, ready to become a garden." Living things must, however, have appeared upon its surface at some very remote epoch, since their remains are to be found far down in the rocks which at present constitute its crust. But how, it must be asked, is the first appearance of living matter upon the earth to be accounted for?
We should not needlessly invoke an abnormal act of Creative Power, we must not even resort to a "moss-grown fragment from the ruins of another world," unless it is really necessary to invent some such hypothesis. Now, the Evolutionist repudiates the notion of Creation in its ordinary sense; he believes that the operation of natural causes, working in their accustomed manner, was alone quite adequate to bring into existence a kind of matter presenting a new order of complexity, and displaying the phenomena which we have generalized under the word "Life." Living matter is thus supposed to have come into being by the further operation, under new conditions, of the same agencies as had previously led to the formation of the various inorganic constituents of the earth's crust—such mineral and saline substances as we see around us at the present day. What we call "Life," then, is regarded as one of the natural results of the growing complexity of our primal nebula. So that, in accordance with this view, we have no more reason to postulate a miraculous interference or exercise of Creative Power to account for the evolution of living matter in any suitable portion of the Universe (whether it be on this earth or elsewhere), than to explain the appearance of any other kind of matter—the magnetic oxide of iron, for instance. So far, all thorough Evolutionists are quite agreed. This is the view of Spencer, Lewes, Huxley, and others—possibly of Darwin. I say possibly of Darwin, because on this subject it so happens that the language of this most distinguished exponent of Evolution is more than usually tinctured with a previous point of view. Speaking of the probable commencement of Life upon our globe, Mr. Darwin says: "I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number. Analogy would lead me one step farther, namely, to the belief that all animals and plants have descended from some one prototype.... There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms, or into one; and that while this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms, most beautiful and most wonderful, have been and are being evolved." Taking into account the phraseology made use of in the above quotation, we have little difficulty in recognizing the views of an Evolutionist, dwarfed and modified though they are by an ultimate appeal to a Creative act only a little less miraculous and singular than the mythical origin of our reputed ancestors—Adam and Eve. Some existing naturalists may perhaps contend that Mr. Darwin ought to have kept more closely to the Mosaic record––replacing his one primordial form by a dual birth of male and female, without whose mutual influence no "biological individuals" can in their opinion come into existence. Such a supposition, it is true, would be as antiquated and unnecessary from the Evolutionist's point of view as is the whole notion of life having been originally "breathed" into one or more organic forms. Mr. Spencer's language is happily free from both these defects: he neither uses the phraseology of the Creative hypothesis, nor does he adopt a definition of biological "individuality," at variance with the Evolution philosophy. He distinctly teaches that living matter must have been at first formless, and that multiplication would have taken place, as among the lowest forms of the present day, exclusively by agamic methods—nay, more, he teaches that living matter must have been the gradual product or outcome of antecedent material combinations. "Construed in terms of evolution," he says, "every kind of being is conceived as a product of modifications wrought by insensible gradations on a preexisting kind of being, and this holds fully of the supposed 'commencements of organic life,' as of all subsequent developments of organic life." But on the question whether the process of Archebiosis (life-evolution) is likely to have occurred once only, as Mr. Darwin seems to hint, or in multitudinous centres scattered over the earth's surface, Mr. Spencer makes no definite statement. The latter belief would, however, be entirely in accordance with his general doctrine; and we seem all the more entitled to infer that Mr. Spencer inclines to the notion of a multiple occurrence of Archebiosis, both in space and in time, since he does not reject the possibility of its occurrence in our own day. Granting "that the formation of organic matter and the evolution of life in its lowest forms may go on under existing cosmical conditions," he believes it "more likely that the formation of such matter and of such forms took place at a time when the heat of the earth's surface was falling through those ranges of temperature at which the higher organic compounds are unstable." But conclusions which we are only able to infer from the writings of Mr. Spencer have been distinctly enunciated by Mr. G. H. Lewes. In a criticism of the "Darwinian Hypothesis," he very forcibly pointed out that it is quite compatible with the hypothesis of evolution to admit a variety of starting-points for the formation of living matter, and he consequently laid down in principle a very important extension of the Darwinian doctrine, in its application to higher organisms. He says: "Although observation reveals that the bond of kinship does really unite many divergent forms, and the principle of Descent with Natural Selection will account for many of the resemblances and differences, there is at present no warrant for assuming that all resemblances and differences are due to this one cause, but, on the contrary, we are justified in assuming a deeper principle which may be thus formulated: All the complex organisms are evolved from organisms less complex, as these were evolved from simpler forms: the link which unites all organisms is not always the common bond of heritage, but the uniformity of organic laws acting under uniform conditions.... It is therefore consistent with the hypothesis of Evolution to admit a variety of origins or starting-points." In this paper Mr. Lewes distinctly postulates the probability of a repetition of the process of Archebiosis, wherever the conditions were favorable, and though he says nothing against the continuance of such a process in the present day, neither does he dwell upon it as a probability.
Prof. Huxley's opinions on the subject of Archebiosis are very similar to those of Mr. Spencer, with the exception that he seems more strongly opposed to the notion of its occurrence at the present day, and it is to this aspect of the question that I would now direct the reader's attention. Why should men of such acknowledged eminence in matters of Philosophy and Science as Mr. Herbert Spencer and Prof. Huxley promulgate a notion which seems to involve an arbitrary infringement of the uniformity of Nature?
They would both have us believe that living matter came into being by the operation of natural causes—that is, by the unhindered play of natural affinities operating in and upon matter which had already acquired a certain degree of molecular complexity. They believe that the simpler kinds of mineral and crystalline matter continue to come into being now as they have ever done; nay, more, they believe that the higher kind of matter, originally initiated by the operation of natural causes, continues to grow both in animal and in vegetal forms, solely under similar influences, and yet they consider themselves justified in supposing that natural causes are now no longer able independently to initiate this higher kind of matter (protoplasm). We find Prof. Tyndall also affirming, in the most unhesitating language, the ultimate similarity between crystalline and living matter: affirming that all the various structures by which the two kinds of matter may be represented are equally the "results of the free play of the forces of the atoms and molecules" entering into their composition. And he, too, would have us believe that, while differences in degree of molecular complexity alone separate living from not-living matter, the physical agencies which promote the growth of living matter are now incapable of causing its origination.
Why, we may fairly ask, should a supposed difference be erected by Evolutionists between Origination and Growth in the case of living matter, while no one dreams of making any such distinction in reference to crystalline matter? Is it true that the process of growth differs from the process of origination, and if so in what respects? Philosophically speaking there is little difference. Take the case of the formation of the "silver tree," cited by Prof. Tyndall. A weak galvanic current is passed through a solution of nitrate of silver, and simultaneously, in a first increment of time, a number of molecules of oxygen and of silver begin to aggregate independently into crystals of oxide of silver; in a second increment of time the operation of the same causes produces similar results, only now part of the new crystalline matter forms in connection with the preëxisting germs of crystals, though part of it may still aggregate independently. During a third, a fourth, and in all succeeding increments of time, in which the same causes operate amid similar conditions, similar results must ensue. But, taking the process of origination which occurs in the first increment of time, would Prof. Tyndall have us believe that it is in any way different from that of growth which takes place in a second, third, or fourth increment of time? Does not the very fact that origination and growth so often occur simultaneously in the case of crystalline matter, and under the influence of the same causes, show us that the two processes are intrinsically similar, and that conditions favorable for growth are also likely to be favorable for origination? And if this be true for crystalline matter, may we not infer that it would also be true for living matter? These are questions neither asked nor answered in any definite manner by those whose opinions I have already cited. They are, however, questions by no means unworthy of an attentive consideration.
Although, as a general rule, conditions favorable for the growth of any particular kind of crystalline matter are likely to be favorable for its origination, still it must be acknowledged that the presence of a crystal will occasionally lead to its growth in a medium in which similar crystalline matter had previously shown no tendency to form independently—even in cases where the introduction of a non-crystalline nucleus would not be able to determine a similar formation of crystalline matter. In spite of the general law, therefore, that conditions favorable for the growth are also favorable for the origination of crystalline matter, we are compelled to admit that growth may be determined under certain conditions where origination does not occur, and that the presence of preëxisting crystalline matter favors the process. Now, a distinction of the same kind undoubtedly obtains in the case of living matter. We know, quite positively, that, although Bacteria will not originate in a previously-boiled ammonic tartrate solution, or "Pasteur's solution," the addition of a few of these organisms (all other conditions remaining the same) will soon occasion a very considerable growth of the living matter of which they are composed. We are thus reduced to ask whether the influence of the preëxisting nucleus is relatively more potent in the case of living matter than it is in the case of crystalline matter? This is a question which unfortunately we are unable definitely to answer. But, so long as we have no positive knowledge on this subject, we surely have little right to infer that processes both of origination and of growth continue in the case of crystalline matter, while the process of growth alone survives in the case of living matter. There are no facts easily discoverable upon which such an assumption can be legitimately based.
The probabilities would seem altogether in favor of the continuance of a natural process like Archebiosis after it had been once initiated, more especially when this natural process is so closely allied to another which manifests itself with the utmost readiness on all parts of the earth's surface. So that, unless very cogent reasons could be adduced against the occurrence of Archebiosis at the present day, looked at from an a priori point of view, there seems scarcely room for doubt upon the subject. The properties and chemical tendencies of material bodies seem to be quite constant through both time and space. Speaking upon this subject in a recent discourse on "Molecules," Prof. Clarke Maxwell says: "We can procure specimens of oxygen from very different sources, from the air, from water, from rocks of every geological epoch. The history of these specimens has been very different, and, if, during thousands of years, difference of circumstances could produce difference of properties, these specimens of oxygen would show it. . . . In like manner, we may procure hydrogen from water, from coal, or, as Graham did, from meteoric iron. Take two litres of any specimen of hydrogen, it will combine with exactly one litre of any specimen of oxygen, and will form exactly two litres of the vapor of water.... Now, if, during the whole previous history of either specimen, whether imprisoned in the rocks, flowing in the sea, or careering through unknown regions with the meteorites, any modification of the molecules had taken place, these relations would no longer be preserved.... But we have another and an entirely different method of comparing the properties of molecules. The molecule, though indestructible, is not a hard, rigid body, but is capable of internal movements, and, when these are excited, it emits rays, the wave-length of which is a measure of the time of vibration of the molecule.... By means of the spectroscope the wave-lengths of different kinds of light may be compared to within one ten-thousandth part. In this way it has been ascertained, not only that molecules taken from every specimen of hydrogen in our laboratories have the same set of periods of vibration, but that light having the same set of periods of vibration is emitted from the sun and from the fixed stars.... We are thus assured that molecules of the same nature as those of our hydrogen exist in those distant regions, or at least did exist when the light by which we see them was emitted." With evidence such as this before us, which could be multiplied to an enormous extent, we should hesitate before needlessly postulating any infringement of the uniformity of natural phenomena.
What, then, are the reasons assigned for the non-occurrence, at the present day, of the process of Archebiosis? All that Mr. Spencer says upon the subject is, that such a process seems to him more likely to have occurred at "a time when the heat of the earth's surface was falling through those ranges of temperature at which the higher organic compounds are unstable," than at the present day. Why such conditions would be more favorable than those now existing Mr. Spencer does not say; and that such an alteration should suffice to put a stop to Archebiosis, although we see living matter still growing freely all over the earth under the most diverse conditions as regards temperature, seems very difficult to believe. Yet no other suggestion is offered in explanation of an assumption which seems essentially unscientific. For the assumption that Archebiosis took place only in the remote past puts this process on a quasi miraculous level, and tends to assimilate it to an act of special creation, the very notion of which Mr. Spencer, in other cases, resolutely rejects.
Again, what reason does Prof. Huxley give, in explanation of his supposition as to the present non-occurrence of Archebiosis? He says if it were given to him "to look beyond the abyss of geologically-recorded time," to a still more remote period of the earth's history, he would expect "to be a witness to the evolution of living protoplasm from non-living matter." And the only reason distinctly implied why a similar process should not occur at the present day is, because the physical and chemical conditions of the earth's surface were different in the past from what they are now. And yet, concerning the exact nature of these differences, and the degree in which the different sets of conditions would respectively favor the occurrence or arrest of an evolution of living matter, Prof. Huxley cannot possess even the vaguest knowledge. He chooses to assume that the unknown conditions existing in the past were more favorable to Archebiosis than those now in operation. This, however, is a mere assumption which may be entirely opposed to the facts. It is useless, of course, to argue upon such a subject, but still it might fairly be said, in opposition to his assumption of the impotency of present telluric conditions, that the abundance of dead organic matter now existing in a state of solution would seem to afford a much more easy starting-point for life-evolution than could have existed in that remote past, when no living matter had previously been formed, and consequently when no dead organic matter, thence derived, could have been diffused over the earth's surface.
Prof. Huxley is, however, very inconsistent, since, in spite of his declared expectation of witnessing the evolution of living from lifeless matter, if it were given him "to look beyond the abyss of geologically-recorded time," he had said, scarcely five minutes before, in reference to experimental evidence bearing upon the present occurrence of a similar process, that, "if, in the present state of science, the alternative is offered us—either germs can stand a greater heat than has been supposed, or the molecules of dead matter, for no valid or intelligible reason that is assigned, are able to rearrange themselves into living bodies, exactly such as can be demonstrated to be frequently produced in another way—I cannot understand how choice can be, even for a moment, doubtful." Having thus expressed himself, it was a little strange that Prof. Huxley forgot to inform his audience, five minutes afterward, what "valid or intelligible reason" he was able to assign for the occurrence of that evolution of non-living matter into living protoplasm in the remote past to which he alluded. A supernatural interposition of Creative Power would explain the presence of living things upon our earth, just as easily as a supernatural preservation of living matter from the destructive effects of heat would account for the presence of living organisms within certain experimental flasks. But Prof. Huxley most inconsistently says that, even in the face of scientific evidence concerning the destructive powers of heat upon living matter, he would rather explain the presence of organisms in certain flasks on the hypothesis of a (supernatural) preservation of germs, than believe in the otherwise proved occurrence of a present life-evolution, similar to that which he assumes to have taken place in the past. He is willing to accept the supernatural in the present, though he declines to interpret the past by its aid. He assumes this attitude because no "valid or intelligible reason" is assigned in explanation of life-evolution, a belief in which would render unnecessary any appeal to the supernatural in the present; though he himself postulates the occurrence of the same unexplained process in the past, solely in order to avoid recourse to the supernatural. Prof. Huxley's position in reference to this question is very puzzling, and one cannot help wondering through what monochromatic glass he had been taking his observations (from his "watch-tower"), in order to come to the conclusion that "the present state of science" gives any sanction to such vacillations, or entitles him to appeal to a supernatural preservation of germs, instead of trusting to the known uniformity of natural phenomena.
Sir William Thomson was certainly much more consistent. He, too, seemed inclined to explain the experiments of our own day by resorting to the hypothesis of a supernatural preservation of germs, and similarly, he seems not unwilling to explain the original advent of Life upon this globe, by another assumed process of "Contagion." He has resort neither to a creative hypothesis nor to the hypothesis of a natural becoming of living matter, but, shelving the question of "origin" altogether, he suggests that our earth may have become peopled with organic forms, owing to the advent upon it, in the remote past, of a "moss-grown fragment from the ruins of another world." Sir William Thomson's hypothesis seems strangely improbable in itself, though it has, in comparison with the views of others, the somewhat rare merit of being not inconsistent with his notions concerning the experiments of to-day. He does not reject the supernatural in the past, while resorting to it for the present—he resorts to it in the present and in the past alike, and curiously evades the problem of origin altogether.
Since so little—or, rather, nothing—is said by Prof. Huxley in support of his supposition that living matter does not originate in the present day, even though the process of origination is so closely akin to that of growth; and, though the process of growth is taking place at every moment of our lives, in every region of the globe, and under the most varied conditions—amid tropical heat and icy coldness, on mountain-tops and deep down in almost unfathomable ocean-beds—it seems only reasonable to suppose that he must have been influenced by some prepossessions. And, so far as one can gather from his presidential address before the British Association—from which I have already quoted—he does not appear to have been powerfully biased by theoretical considerations. One of these we shall now consider.
Much stress is laid by certain writers upon the fact that "the doctrine of spontaneous or equivocal generation has been chased successively to lower and lower stations in the world of organized beings, as our means of investigation have improved." So that, as another very eminent writer says, "if some apparent exceptions still exist, they are of the lowest and simplest forms." And it is usually inferred from this fact that further knowledge and improved means of observation will prove these apparent exceptions to be no exceptions to the supposed general rule—omne vivum ex vivo. A consideration of this kind seems to have powerfully influenced Prof. Huxley. But much confusion exists in reference to the point, which needs to be removed. In the first place, it must be freely admitted that many ancient notions, dating from the time of Aristotle, on the subject of "Equivocal or Spontaneous Generation," were altogether crude and absurd. Secondly, it is necessary to distinguish (and Prof. Huxley did so) between two meanings of the phrase, which have often been confounded with one another—viz., between Heterogenesis, or the mere allotropic modification of already existing living matter, and Archebiosis, or the independent origination of living matter. Thirdly, it should be distinctly understood that those who strictly adhere to the Evolution hypothesis could never believe in the origination of any but the "lowest and simplest" organic forms by a process of Archebiosis. So that, as Prof. Huxley professes himself an Evolutionist, the objection above indicated should have been quite pointless for him. Molecular combinations, giving rise to units of protoplasm far below the minimum visible stage of our most powerful microscope, would represent those initial collocations by which alone living matter could come into being—though the "germs" thus initiated may afterward appear as minutest visible specks growing into Bacteria, Vibriones, or Torulæ. We may, therefore, be permitted to remark that, even if it were given to Prof. Huxley to "look beyond the abyss of geologically-recorded time," he would be extremely unlikely to witness an "evolution of living protoplasm from not-living matter." At the most, he might see (that is, if equipped with a powerful microscope) only what he may equally well see now—viz., a gradual emergence into the sphere of the visible of minute specks of living protoplasm. But though he might, when looking back to this remote age, be inclined to consider such appearances as testifying to the evolution of living protoplasm from not-living matter, he would perchance find it just as difficult to convince others of the absence of invisible Salamandrine germs (derived, perhaps, from the "moss-grown fragment of another world") as he is himself difficult to be convinced by similar appearances at the present day. Prof. Huxley seems, for the time, to have lost sight of a consideration justly deemed by Prof. Tyndall to be one of great importance in the interpretation of evolutional phenomena—viz., the enormous difference in point of size between the first constituent molecules of protoplasm and the minutest visible organisms. As Prof. Tyndall puts it, compared with their constituent elements, "the smallest vibrios and bacteria of the microscopic field are as behemoth and leviathan," even though the latter are often less than 1⁄30000 of an inch in diameter.
Thus it would appear that a consistent belief in the Evolution hypothesis necessarily carries with it a belief in the continuance of the process of Archebiosis from the remote epoch when living matter first appeared upon this earth down to the present time. The Evolutionist teaches us that living matter is not in its essence different from other kinds of matter, and that it originally came into being, like the various forms of mineral and crystalline matter, by the operation of mere natural causes. As Prof. Huxley says: "Carbon, hydrogen, oxygen, and nitrogen, are all lifeless bodies. Of these carbon and oxygen unite in certain proportions and under certain conditions to give rise to carbonic acid; hydrogen and oxygen produce water; nitrogen and hydrogen give rise to ammonia. These new compounds, like the elementary bodies of which they are composed, are lifeless. But, when they are brought together under certain conditions, they give rise to the still more complex body, protoplasm; and this protoplasm exhibits the phenomena of life." So that, if living matter has once arisen naturally and independently, the laws of uniformity alone, upon which all science is based, should lead us to expect that it would continue to have a similar "origin" so long as such matter continued to "grow" under the most varied conditions upon and beneath the earth's surface. And, these conditions being fulfilled, we have a good a priori warrant for the belief that living matter is continually coming into being by virtue of the operation of the same "laws" or molecular properties as suffice to regulate its growth.
Let the Evolutionist attempt to deny it, and see what other difficulties he plunges into, in addition to that lack of consistency which I have already pointed out.
If an evolution of living matter occurred only far back beyond the depths of geologically-recorded time, and if, as Mr. Darwin would have us believe, "all the living forms of life are the lineal descendants of those which lived long before the Cambrian epoch," how is the Evolutionist to explain the existence of the multitudinous myriads of lowest and almost structureless organisms which exist at the present day? He starts, in his argument in favor of Evolution, from the fact that the condition of homogeneity is one of necessarily unstable equilibrium. All homogeneous matter inevitably tends to become heterogeneous, and, of the different kinds of matter, none unites within itself the various qualities tending to favor this passage from the homogeneous to the heterogeneous in the same degree as living matter. These tendencies are daily exemplified to us by the phases of embryonic development passed through by the more or less homogeneous germs of multitudinous complex organisms from which they proceed. The embryonic development of one of the higher animals—of man himself, for instance—is a kind of highly-condensed epitome of animal evolution in general. And the varied forms of life of higher organization, both animal and vegetal, which have existed and still exist upon the surface of our earth, are all supposed by the Evolutionist to have arisen by dint of insensible modifications wrought through the long lapse of ages upon successive generations of organic forms. But if living matter contains within itself the potentiality of undergoing such mighty changes and of ever growing in complexity—if from originally structureless protoplasm (that is, structureless, to our senses) all the varied forms of life have been derived, how is it that some of this very same matter should have remained through the long lapse of ages almost in its primitive structureless condition? Why should one portion of the living matter which came into being in pre-Cambrian epochs have passed through such marvelous changes, while another portion has continued to grow, through all the inconceivably numerous generations which must have occurred between that time and the present, without undergoing change?
In other words, what is the meaning of the existence of Bacteria, Torulæ, Amœbæ, and such simplest organisms at the present day? Mr. Spencer saw this difficulty, but apparently did not fully realize its force. He attempts, as it appears to me, very inconsistently to evade it by supposing that living matter may escape increasing organization so long as it can escape the influence of gross changes in external conditions; and, just as inconsistently, he assumes that living matter could escape these changes in external conditions through that long lapse of ages which the lowest estimate regards as a period of no less than 100,000,000 years. Speaking of what he presumes to be ancient though almost structureless organisms, and endeavoring to account for their stationary condition as regards structure, by supposing that they have succeeded through long ages in "dodging" all changes in their environment, Mr. Spencer says: "New influences are escaped by the survival of species in the unchanged parts of their habitats, or by their spread into neighboring habitats which the change has rendered like their original habitats, or by both."
Now, in opposition to these views of Mr. Spencer, many very cogent objections may be alleged. In the first place, in supposing that the organization of living matter would not increase even through ages of time unless it were subject to marked variations in external conditions, Mr. Spencer makes a supposition which seems notably at variance with his own doctrines of Evolution. Does he not for a time ignore those internal causes of change which must ever be in operation within living matter as within all other kinds of matter—and which, even in combination with approximately fixed external conditions, should suffice to produce a continually-increasing differentiation (organization) in living matter? Mr. Spencer himself says: "All finite forms of the homogeneous—all forms of it which we can know or conceive—must inevitably lapse into heterogeneity. In three several ways does the persistence of force necessitate this. Setting external agencies aside, each unit of a homogeneous whole must be differently affected from any of the rest by the aggregate action of the rest upon it. The resultant forces exercised by the aggregate on each unit, being in no case alike both in amount and direction, cannot produce like effects on the units. And the various positions of the parts in relation to any incident force preventing them from receiving it in uniform amounts and directions, a further difference in the effect wrought on them is inevitably produced." Even this is not all; Mr. Spencer also points out that "every differentiated part is not simply a seat of further differentiations, but also a parent of further differentiations; since, in growing unlike other parts, it becomes a centre of unlike reactions on incident forces, and, by so adding to the diversity of forces at work, adds to the diversity of effects produced. This multiplication of effects is proved to be similarly traceable throughout Nature." Now, if causes like these are inevitably at work upon and within the simplest forms of life, no change in external conditions would be needed in order to insure an increasing complexity of structure, through months or years, to say nothing about long ages of time. But, as a matter of fact, granting that the liability of organisms to increase in complexity of structure "arises from the actions and reactions between organisms and their fluctuating environments," and seeing that these changes in the environment are enumerated by Mr. Spencer as being due to "astronomic, geologic, meteorologic, and organic agencies," organisms never could by any possibility shelter themselves through long ages of time even from the influence of these external inciters of change. Mr. Spencer's explanation of the cause of the existence of multitudinous almost structureless organisms at the present day, therefore, entirely falls to the ground. The lowest organisms can neither escape the incidence of new external conditions (such as we know from actual observation do powerfully modify them), neither, if they could, should the progress of organization thereby cease—since the internal causes of change would still remain active and still continue to give rise to a "multiplication of effects," as Mr. Spencer has himself explained.
Thus, the existence of such lowest and simplest organisms as the microscope everywhere reveals at the present day, is quite irreconcilable with the position that life-evolution has not occurred since an epoch inconceivably remote in Time. Admit the present occurrence of Archebiosis and Heterogenesis, and both the existence and protean variability of the lowest organisms are at once readily explained. We may suppose them continually seething into existence afresh, endowed with enormous plasticity; so that new recruits are constantly appearing, ever ready to fill up the gaps which would otherwise be occasioned by promotion and death. The opposite doctrine, concerning such organisms as the structureless Amœba and the insignificant Mucor now daily appearing on decaying substances, seems opposed to all reason from the point of view of the Evolution Philosophy. As I have elsewhere asked: "Would the Evolutionist really have us believe that such forms are direct continuations of an equally structureless matter which has existed for millions and millions of years without having undergone any differentiation? Would he have us believe that the simplest and most structureless Amœba of the present day can boast of a line of ancestors stretching back to such far remote periods that in comparison with them the primeval men were but as things of yesterday? The notion surely is preposterously absurd; or, if true, the fact would be sufficient to overthrow the very first principles of their own Evolution philosophy."—Author's Advance Sheets.
- "System of Logic," sixth edition, vol. ii., p. 98.
- Inaugural Address at Meeting of British Association, Nature, August 3, 1871, p. 269.
- "Origin of Species," sixth edition, 1872, pp. 424, 429.
- "Principles of Biology," vol. ii., Appendix, p. 482.
- Fortnightly Review, 1868.
- "Inaugural Address at Meeting of British Association," Nature, September 15, 1870, p. 404.
- "Fragments of Science," fourth edition (1872), pp. 85-87, and 113-119.
- "The Beginnings of Life," vol. i., p. 325.
- Nature, September 25, 1873, p. 440.
- Nature, September 15, 1870, p. 404.
- This is a consideration of great importance, since those who believe that Archebiosis occurs in organic solutions at the present day have not yet professed to show that it can occur in saline solutions free from all traces of organic matter.
- Prof. Lister, "Introductory Lecture" (University of Edinburgh), 1869, p. 12.
- Mr. Justice Grove ("Presidential Address"), Report of British Association for the Advancement of Science, 1866, p. 71.
- "Fragments of Science," fourth edition, 1872, p. 151.
- Fortnightly Review, February, 1869.
- "Origin of Species," sixth edition, p. 428.
- The multiplication of the lowest forms of life takes place so simply that, as Prof. Huxley has pointed out, it is nothing more than a process of "discontinuous growth."
- Especially when Mr. Darwin says: "Judging from the past, we may safely infer that not one living species will transmit its unaltered likeness to a distant futurity."—"Origin of Species" (1872), sixth edition, p. 428.
- "First Principles," second edition, pp. 429, 548.
- "The Beginnings of Life," 1872, vol. i., p. 12.