As these varieties (or incipient species, as Darwin conceives them to be) were formed through the selection by man of slight successive modifications, Darwin affects to believe that variations arose in the wild state; that they were accumulated and preserved by nature by a process analogous to man's selection; and that by the long continued accumulation and conservation, through countless ages, of these modifications, the species have evolved from one another. This selective power of nature he infers from the struggle for existence constantly carried on in the wild state, wherein the weak succumb, and the fittest, strongest, and most vigorous survive, and, according to the theory, attain to a higher development.
Many objections have been urged against Darwin's theory. Some have questioned the efficiency of natural selection; and others have contended that selection necessarily implies a selecter. Some have considered Darwinism sufficiently disproved by the absence of the transitional links between the different species. Others have asserted the inconceivableness of the primordial differentiation of parts in organisms when they all presented the simplest structure. Another argument has been adduced from the tendency of domesticated animals and plants, when neglected, to recur to the ancestral form under nature. Some assume a limit to variation; while others have contended that domestication of itself has introduced something plastic into organisms, enabling them to vary, and that, therefore, the analogy drawn between animals and plants under domestication and those under nature is inadmissible. Others assert that domestic animals and plants have been rendered in an especial manner subservient to the uses and purposes of man. In conformity with this view, they also affirm that the conception of species is, for that reason, not applicable to the creatures under domestication. For ourselves, we concede that the analogy between domesticated and natural animals and plants is a just one, in the light in which the phenomena of variation are generally regarded. For we wholly dissent from the opinion of the introduction by domestication of any thing plastic into organisms, and firmly believe in the operation of secondary causes in the formation of varieties.
These arguments, in the form in which they are adduced, are inconclusive. Their weakness springs from an error into which those who have urged them have fallen, which vitiates at the start all their reasoning. To this error we shall presently advert. But while we cannot concur in their premises, we have something more than an intuition of the truth of their common conclusion.
The facts, of which the Animals and Plants under Domestication is a vast repertory, admit of a theory more conformable than that of Darwin to the phenomena of variation; a theory which fully accounts for the appearance of the profitable modifications under domestication, (confessedly inexplicable on Darwin's theory,) and for the formation of races under nature; a theory admitting of still further variation; and which is at the same time strictly in accordance with the doctrines of special creations and of the immutability of the species. This teleological explanation, of which we conceive the phenomena of variation to be susceptible, we will render amenable to all the canons of scientific research. And in doing so, we will rely for our proofs upon no evidence but that furnished us by noted evolutionists.
The seeming concurrence of all the evidence in favor of Darwinism results from a misconception by all of the true nature of its data. In all the arguments adduced by the advocates of special creation in disproof of Darwin's hypotheses, these variations have been tacitly admitted to arise by evolution. That they have thus arisen seems to be taken for granted. In this admission lies their error. Upon this current conception of varietal evolution rests the whole evolution hypothesis. Upon the validity of this assumption we join issue with Darwin, as we conceive that upon this point the whole question hinges. For it is not a little illogical to concede the evolution of varieties, and to deny the evolution of species. If we can show that this assumption is invalid, the whole evolution fabric will fall.
Darwin tacitly assumes that the existing state of nature is the normal or primordial condition of animals and plants. The difficulty hitherto experienced in confuting his errors springs from acquiescence in this assumption. True it is that Darwin does not believe in the validity of this assumption, but merely makes it to show the inconceivableness of the negation of evolution. With him a species is not fixed but fluctuating, and is merely a subjective conception, having no objective reality. Believing in the converse assumption, we advance the following theory: That animals and plants have degenerated under nature, and that the favorable modifications arising under domestication are due to reversion to the perfect type.
Darwin, in treating of variations, refers them indiscriminately to reversion and to evolution. This he does according to no law, rule, method, or formula. The mere circumstance that he has one subject under consideration, suffices to induce him to ascribe to reversion a modification which, in another portion of his work, he, with strange inconsistency, attributes to "spontaneous variability." He affects to deem it a sufficient answer to the ascription of characters to reversion, to appeal to the absence of such characters in the species under nature. If the assumption of degeneration and subsequent favorable reversion can lay even the least claim to tenability, this answer is in no wise satisfactory. If it can be conclusively shown that most, if not all, creatures in a state of nature, are in a degenerated condition, then the irresistible inference will be, in the absence of any other rational explanation, that favorable variations are ascribable to reversion.
While, as Herbert Spencer says, "a comparison of ancient and modern members of the types which have existed from paleozoic and mesozoic times down to the present day shows that the total amount of change (in animals) is not relatively great, and that it is not manifestly toward a higher organization," paleontology furnishes us with many facts showing the great size of ancient mammals, and marked degeneracy in their descendants. Thus, Darwin concurs with Bell, Cuvier, Nilsson, and others in the belief that European cattle—the Continental and Pembroke breeds, and the Chillingham cattle—are the degenerate descendants of the great urus, (bos primigenius,) with which they cannot now sustain a comparison, so greatly have they degenerated. Cæsar describes the urus as being not much inferior in size to the elephant. An entire skull of one, found in Perthshire, measures one yard in length, while the span of the horn cores is three feet and six inches, the breadth of the forehead between the horns is ten and a half inches, and from the middle of the occipital ridge to the back of the orbit it is thirteen inches, (Owen's British Fossil Mammals, pp. 500, 501, 502.) The common red deer have so greatly undergone degeneration that the fossil remains of their progenitors have been held to be those of a distinct species, (strongylocerus spelæus.) An advocate of Darwinism—a writer in the Edinburgh Review for October, 1868—differs with Owen on this point, and holds that the common red deer are their descendants, greatly degenerated. From their antlers it is inferred that they equalled in height the megaceros, whose height to summit of antlers was ten feet four inches, (Owen's British Foss. Mam.) So marked is the difference in the size of the antlers, says the Edinburgh reviewer, that it would be possible to ascertain approximately the antiquity of a deposit in which they might be found from that fact alone. The horse and the elephas antiquus have also been shown to have decreased in size.
Changes similar to these have been adduced by the advocates of evolution, to show the manner in which species have been formed under nature. But these, we apprehend, imply devolution rather than evolution. They also serve, contend they, as illustrations of the harmony subsisting between the organism and its environment. If by this is meant that the organism responds to every marked change in the environment, we admit the harmony. But if congruity between a perfect physiological state and the changed conditions is implied, we demur. Certain conditions are absolutely essential to the growth of characters and to general perfection. When they are so modified as to entail the diminution or loss of any positive feature, this tells upon the organism. Darwin, noting that the appearance of certain characters was invariably consequent upon the presence of certain conditions, says (in order to avoid any thing like a teleological implication) that we must not thence infer that those or any conditions are absolutely necessary to the growth of any organs or characters. That Darwin errs, and that full physiological perfection cannot exist except where there is full general growth, and full growth of all parts or organs, we shall clearly demonstrate when, in a future article, we treat of the laws of compensation or balancement of growth, of correlation, of crossing, and of close interbreeding. But whether there exists harmony between the organism or not, there is none the less deterioration. And when reversion to the type from which the organism has degenerated takes place under domestication, it is termed evolution.
But those proofs of degeneration and subsequent favorable reversion upon which we chiefly rely are those afforded by Darwin himself. On page 8, Vol. I. of his late work, he says, "Members of a high group might even become, and this apparently has occurred, fitted for simpler conditions of life; and in this case, natural selection would tend to simplify or degrade the organism; for complicated mechanism for simple actions would be useless or even disadvantageous." The efficiency of natural selection in this respect we fully concede.