Creation or Evolution? A Philosophical Inquiry

by George Ticknor Curtis

3. Morphology, or the science of form, involves a comparison of the structure of different organisms in their mature state; an ascertainment of the resemblances between their structures, and of the community of plan that exists between them. Here, as in the aids derived from classification and embryology, it is claimed that the fundamental likenesses of forms of structure have a meaning which is altogether inconsistent with the hypothesis of predetermined typical plans pursued throughout immensely varied forms of organisms.

4. Distribution: This is the term applied to the phenomena exhibited by the presence of different organisms in different localities of the globe; or, as Mr. Spencer phrases it, "the phenomena of distribution in space." These phenomena are very various. Sometimes, it is said, we find adjacent territories, with similar conditions, occupied by quite different faunas. In other regions, we find closely allied faunas in areas remote from each other in latitude, and contrasted in both soil and climate. The reasoning, as given by Mr. Darwin and adopted by Mr. Spencer, is this: that "as like organisms are not universally or even generally found in like habitats, nor very unlike organisms in very unlike habitats, there is no predetermined adaptation of the organisms to the habitats." "In other words," Mr. Spencer adds, "the facts of distribution in space do not conform to the hypothesis of design." The reason why they do not is claimed to be that there are impassable barriers between the similar areas which are peopled by dissimilar forms; whereas there are no such barriers between the dissimilar areas which are peopled by dissimilar forms. The conclusion is, "that each species of organism tends ever to expand its sphere of existence—to intrude on other areas, other modes of life, other media." That is to say, there is a constant competition among races of organisms for possession of the fields in which they can find the means of subsistence and expansion; and this leads to new modes of existence, new media of life, new structures and new habitats.

The reader can now retrace his steps, and advert to the facts that are relied upon, under the four heads of the argument:

1. With regard to the argument derived from classification: it is to be observed that any system of classification is in a certain sense artificial, and at all events is manifestly conventional. But, in order that no injustice may be done to this branch of the argument for evolution, I shall state it in its full force. The classifications which naturalists make of the different organized beings according to their resemblances and differences reveal the fact of unity amid multiformity. This fact it is said points to propinquity of descent, "which is the only known cause of the similarity of organic beings." It is the bond, hidden indeed by various degrees of modification, but nevertheless revealed to us by the classifications which display the resemblances. Again, we have, it is said, in the influence of various conditions of animated organisms, "the only known cause of divergence of structure." Classification reveals to us these divergences. We have, then, the bond of resemblances which indicate propinquity of descent, and the divergences of structure produced by varying conditions of life. Put the two together, and we have remarkable harmonies of likenesses obscured by unlikenesses; and to this state of facts it is claimed that no consistent interpretation can be given, without the hypothesis that the likenesses and the unlikenesses were produced by the evolution of organisms out of organisms by successive generation, through a great lapse of time.

This argument contains no inconsiderable amount of assumption. While it may be true that some naturalists do not assign any cause for the similarity which obtains among organic beings excepting their descent from a common ancestral stock, it is not true that the similarity of structure is inconsistent with the hypothesis of another cause, namely, the adoption of a general plan of structure for a large class of organisms, and an intentional variation in those parts of structure which mark the divisions of that class into species that are very unlike. It is true that evolutionists treat with scorn the idea of a pattern of structure followed throughout a class of animals, but made by designed adaptations to coalesce with differences that mark the peculiarities which distinguish one organism of that class from all the others. Mr. Spencer, for example, observes that "to say that the Creator followed a pattern throughout, merely for the purpose of maintaining the pattern, is to assign a motive which, if avowed by a human being, we should call whimsical."

Let us now follow this mode of disposing of the hypothesis of special creations, by adverting to some of the facts that are adduced in its summary condemnation; and, although the passage which I am about to quote is found in Mr. Spencer's work under the head of morphology, the illustration applies equally well to his argument from classification. Speaking of fundamental likenesses of structure, he says: "Under the immensely varied forms of insects, greatly elongated like the dragon-fly, or contracted in shape like the lady-bird, winged like the butterfly, or wingless like the flea, we find this character in common—there are primarily twenty segments. These segments may be distinctly marked, or they may be so fused as to make it difficult to find the divisions between them. This is not all. It has been shown that the same number of segments is possessed by all the Crustacea. The highly consolidated crab, and the squilla with its long, loosely-jointed divisions, are composed of the same number of somites. Though, in the higher crustaceans, some of these successive indurated rings, forming the exo-skeleton, are never more than partially marked off from each other, yet they are identifiable as homologous with segments, which, in other crustaceans, are definitely divided. What, now, can be the meaning of this community of structure among these hundreds of thousands of species filling the air, burrowing in the earth, swimming in the water, creeping about among the sea-weed, and having such enormous differences of size, outline, and substance, as that no community would be suspected between them? Why, under the down-covered body of the moth and under the hard wing-cases of the beetle, should there be discovered the same number of divisions as in the calcareous framework of the lobster? It can not be by chance that there exist just twenty segments in all these hundreds of thousands of species. There is no reason to think it was necessary, in the sense that no other number would have made a possible organism. And to say that it is the result of design—to say that the Creator followed this pattern throughout, merely for the purpose of maintaining the pattern—is to assign a motive which, if avowed by a human being, we should call whimsical. No rational interpretation of this, and hosts of like morphological truths, can be given except by the hypothesis of evolution; and from the hypothesis of evolution they are corollaries. If organic forms have arisen from common stocks by perpetual divergences and redivergences—if they have continued to inherit, more or less clearly, the characters of ancestral races, then there will naturally result these communities of fundamental structure among extensive assemblages of creatures, that have severally become modified in countless ways and degrees, in adaptation to their respective modes of life. To this let it be added that, while the belief in an intentional adhesion to a predetermined pattern throughout a whole group is totally negatived by the occurrence of occasional deviations from the pattern, such deviations are reconcilable with the belief in evolution. As pointed out in the last chapter, there is reason to think that remote ancestral traits will be obscured more or less according as the superposed modifications of structure have or have not been great or long maintained. Hence, though the occurrence of articulate animals, such as spiders and mites, having fewer than twenty segments, is fatal to the supposition that twenty segments was decided on for the three groups of superior Articulata, it is not incongruous with the supposition that some primitive races of articulate animals bequeathed to these three groups this common typical character—a character which has nevertheless, in many cases, become greatly obscured, and in some of the most aberrant orders of these classes quite lost."[81]

Whatever may be the explanation suggested by one or another hypothesis as to the mode in which this uniformity of structure came to exist, it is certain that it does exist. Twenty segments are found in hundreds of thousands of species which are immensely different from each other in size, outline, substance and modes of existence. Here, then, is a plan. There is a pattern, on which all these different organisms are constructed with a common peculiarity. It is averred that this could not have been the result of design, because this would be to impute to the Creator a whimsical motive, namely, that he followed the pattern throughout a vast group of different organisms merely for the purpose of following it. On the contrary, it may be contended that this uniformity of plan, this repeated pattern, affords the highest probable evidence of design; and that the supposed whimsicality of motive will entirely disappear as soon as we reach a purpose which may have had very solid reasons for this uniformity of structure. When we reason about the works of the Creator, we are reasoning about the methods of a being who, we must suppose, is governed by a purpose in all that he does. In reasoning about the methods of such a being, it is entirely unphilosophical to suppose that he has done anything merely for the sake of doing it, or for the sake of exercising or displaying his powers in repetitions that had no practical value. In order to reason consistently with the supposed attributes of the Creator, we should endeavor to find the value of any given pattern which we discover in a certain very large class of organisms differing widely from each other in other respects; and in order to find that value it is by no means essential to make out that the particular plan of construction was necessary to the making of any organism whatever. The true question is, not whether twenty segments were necessary to the construction of any organism, but whether, in each of the different species, this peculiar number of divisions was useful to each particular organism. If naturalists of the evolution school, instead of looking at everything through the medium of a certain theory, would in their dissection, for example, of the framework of the lobster, the body of the moth, and the body of the beetle, furnish us with facts which would show that these twenty divisions are of no use either for strength, or resistance, or suppleness, or adaptation to what is contained within them, we should have a body of evidence that could be claimed as tending to overthrow the hypothesis of intentional design. They might then speak of the repetition of this pattern as whimsical, upon the hypothesis that it was a repetition by design. But so little is done by this class of naturalists to give due consideration to the value of such repetitions, and so little heed is paid to the truth that the Creator does nothing that is useless—a truth which all sound philosophy must assume, because it is a necessary corollary from the attributes of the Creator—that we are left without the aid which we might expect from these specialists in natural science. Is it, then, impossible to discover, or even to suggest, that for each of these organisms this number of twenty divisions had a value? If they were of no value, we may safely conclude that they would never have existed, unless we ignore the hypothesis of infinite wisdom and skill. That hypothesis is a postulate without which we can not reason on the case at all. With it, we have as a starting-point the conception of a being of infinite perfections, who does nothing idly, nothing from whim, nothing from caprice, and nothing that is without value to the creature in which it is found. So that, while we can not in all cases as yet assign that value, we have the strongest reasons for believing that there is a value; and, instead of asserting that an extensive community of structure throughout a great branch of the animal kingdom has no meaning excepting upon the doctrine of evolution, it is the part of true science to assume that it may have another meaning, and to discover if possible what that other meaning is. This is the part of true science, because it is the part of sound philosophy. There is another remark to be made upon Mr. Spencer's reasoning on this particular case of a community of pattern. He says that it can not be imputed to chance. It was, then, either an intentional design, or it came about through the process of descent "from common stocks, which process was at the same time producing perpetual divergences and redivergences." Without turning aside for the present to ask from how many common stocks, it may be shown as in the highest degree probable that the occasional deviations from the pattern did not arise by the evolution process, because that process has in itself an element of chance which is fatal to the theory. The assertion is that "an intentional adhesion to a predetermined plan throughout a whole group is totally negatived by the occurrence of occasional deviations from the pattern." Let this assertion be examined first in the light of facts, and secondly by the absence of facts.

The hypothesis is that some primitive race of articulated animals, possessed by some means of the twenty segments, transmitted this ancestral trait to hundreds of thousands of species having no community of structure in other respects. Unfortunately for the theory, no figures can measure the chances against the preservation of a single pattern through such a multitude of differing organisms descending from a common stock. Infinity alone can express the chances against such a result. While, according to the theory, the deviations from the original type were constantly working out new organisms of the most diversified forms, until there came to be hundreds of thousands of new species differing from each other in all but this one peculiarity—a diversity which is supposed to have been caused by the fundamental law of evolution—how did it happen that the same law did not break this uniformity of articulation? If it was potent enough to differentiate the enormous multitude of these animals in all other traits, why did it not vary the number of segments with which the primitive race was endowed? Is the law of evolution limited or unlimited? If it is limited in its effects, then there are patterns of animal structure which it has not modified, and the presence of which in hundreds of thousands of different species must be explained as a form of structure designed for some end that was to be common to a great multitude of different beings. If the law of evolution was unlimited in its power, then the community of pattern has had to undergo chances of destruction or discontinuance that are immeasurable; as there can be no measure which will represent to the mind the infinitely diversified and innumerable causes that have produced the dissimilarities which compel a classification into the different species, upon the hypothesis of their descent from a common stock. Grant, too, for the purpose of the argument, that the occasional deviations from the pattern of twenty segments, producing a few groups with a smaller number of articulations, are reconcilable with the belief that some later ancestral form became endowed with the smaller number which it transmitted to its descendants. How came that later ancestral form to be endowed with the smaller number of segments? Was there a still more remote ancestral race, which in some way became possessed of the smaller number, or did the spiders and the mites, in the countless generations of evolution, branch off from ancestral races having the full number of twenty segments? Upon either supposition, what an infinity of chances there were, against the natural selection of the smaller number, and against its preservation as the unvarying type of articulation found in the spiders and the mites! The supposition that the number of twenty segments was decided on for the three groups of superior Articulata for the mere sake of adhering to a pattern is doubtless unphilosophical. But it is not unphilosophical to suppose that whatever amount of articulation is found in each species was given to it because in that species it would be useful. If in some of the most aberrant orders of these animals the articulation is greatly obscured, or not found at all, the conclusion that it was not needed, or not needed in a like degree, is far more rational than the theory which commits the particular result to an infinity of chances against it; or which supposes it to have been worked by a process that might have produced a very different result, since it can not be claimed that natural selection works by methods of which any definite result can be predicated more than another.

Thus far I have considered Mr. Spencer's argument from the Articulata in the light of the facts that he adduces. Let us now test it by the absence of facts. In a former discussion, I have asked for facts which show, aside from the theory, that any one species of animal, distinctly marked as a continuing type, is connected by intermediate types or forms with any pre-existing race of another character. Take this class of the articulated animals, said to be of hundreds of thousands of different species having no community of form but this of articulation, and now known as perfect organisms, each after its kind. What naturalist has discovered the continuity of lives with lives, which would furnish the steps of descent of any one of this species from an antecedent and a different species? It is very easy to construct a theory, and from it to argue that there must have been intermediate links, which, if discovered, would show the continuity of lives from lives which the descent of one organism from another necessarily implies. To a certain extent, within certain limits, the sub-groups and the sub-sub-groups of the articulated class of animals, which classification or morphology reveals, may lay the foundation for a theoretical belief in an ancestral stock from which the different and now perfect forms of these distinct animals may have become developed by successive changes of structure. But the extent to which connected changes can be actually traced in the animal kingdom is extremely limited; and the important practical question is whether any one fact, or class of facts, has been discovered which will warrant the belief that beings of totally dissimilar forms and habits of life have, without any design, been evolved by the ordinary process of successive generation, through the operation of causes that have gradually modified the structure in all respects save one, and have at the same time enabled or allowed that one peculiarity of structure to escape from the influences which have modified both structure and modes of life in every other respect. Why, for example, upon the hypothesis of descent from a common stock, has that stock deviated under the influences of natural selection into the lobster, the moth, and the beetle, and yet the community of twenty segments of articulation has entirely escaped the effect of those influences? No reason can be assigned for the fact that it has escaped those influences, excepting that it was originally designed, and was impressed upon the proto-typical stock with such force as to place it beyond the reach of all such causes of modification as those which are ascribed to natural or sexual selection. Without the latter supposition, those causes were just as potent to bring about a modification in the number of articulations as they were to bring about all the astonishing diversities of structure and modes of life that we see, and therefore the most probable conclusion from the fact of this uniformity of the twenty segments is, that there was a barrier placed in this whole class of organisms, which has limited the modifying force of the supposed process of evolution, for the reason of some peculiar utility in this plan of articulation.

Perhaps it will be said that the process of evolution itself tends to the preservation of whatever is most useful, while the modifications are going on which develop new organs and new structures; and that thus, in the case before us, the twenty segments have been preserved throughout an enormous group by one of the fundamental laws of evolution, so that, if there is any peculiar utility in the twenty segments, that utility has been answered by the very process of gradual descent of one organism from another. But the difficulty with this reasoning is, that while it assumes for the modifying influences of natural and sexual selection a range of fortuitous causes sufficient to change the ancestral type into the acquisition of vastly diversified organs, powers, and modes of existence, so as to constitute new animals, it yet assumes that, by some recognition of a superior and paramount utility in the particular number of segments, the law of evolution has preserved that number from the influence of causes which have changed everything else. Now, the range of causes which was sufficiently varied, accidental, long-continued and complex to produce the diversities of structure in all other respects, by the infinitely modifying influences which have developed new organs and new modes of existence, must also have been of a sufficiently varied, accidental, long-continued, and complex character to have broken this plan of the twenty segments, unless we suppose that in some mysterious and inexplicable manner the different generations of these beings were endowed with some kind of sagacity which would enable them to strive for the preservation of this one peculiarity, or unless we suppose that Nature was ever on the watch to guard them from its destruction or variation, on account of its peculiar utility. The first supposition is not in accordance with the evolution theory; for that theory rejects all idea of conscious exertion on the part of any of the organisms. The second supposition leads us at once to the inquiry, how came it to be imposed upon a whole group of beings as a law of nature, that whatever utility of structure was of paramount importance to the whole group should be preserved against the modifying influences that were to produce species differing absolutely from each other, through hundreds of thousands of varieties, in every other feature of their existence? Can we get along here without the hypothesis of design? And, if there was such design, how does the fact of this uniformity amid such diversity become an argument against the hypothesis of a Creator? Or, how does it tend to displace the hypothesis of special creations, when we find that the very process of so-called evolution has failed to break the uniformity of a pattern that is conceded not to have been the result of chance, although that pattern was exposed to just as many and as powerful causes of modification as those which are assumed to have brought about the modifications in every other feature of the animal existence? The truth would seem to be, that the uniformity amid so great a diversity was either the result of a design which placed it out of the reach of all the modifying influences, or else it has, by a most incalculable result, escaped from the effect of those influences by a chance in which the ratio of one to infinity can alone measure the probability of such an escape.