The Case Against Evolution

CHAPTER I. The Present Crisis in Evolutionary Thought

THE PRESENT CRISIS IN EVOLUTIONARY THOUGHT

Three prominent men, a scientist, a publicist, and an orator, have recently made pronouncements on the theory of Evolution. The trio, of course, to whom allusion is made, are Bateson, Wells, and Bryan. As a result of their utterances, there has been a general reawakening of interest in the problem to which they drew attention. Again and again, in popular as well as scientific publications, men are raising and answering the question: “Is Darwinism dead?” Manifold and various are the answers given, but none of them appears to take the form of an unqualified affirmation or negation. Some reply by drawing a distinction between Darwinism, as a synonym for the theory of evolution in general, and Darwinism, in the sense of the particular form of that theory which had Darwin for its author. Modern research, they assure us, has not affected the former, but has necessitated a revision of ideas with respect to the latter. There are other forms of evolution besides Darwinism, and, as a matter of fact, not Darwin, but Lamarck was the originator of the scientific theory of evolution. Others, though imitating the prudence of the first group in their avoidance of a categorical answer, prefer to reply by means of a distinction based upon their interpretation of the realities of the problem rather than upon any mere terminological consideration.

Of the second group, some, like Osborn, distinguish between the law of evolution and the theoretical explanations of this law proposed by individual scientists. The existence of the law itself, they insist, is not open to question; it is only with respect to hypotheses explanatory of the aforesaid law that doubt and disagreement exist. The obvious objection to such a solution is that, if evolution is really a law of nature, it ought to be reducible to some clear-cut mathematical formula comparable to the formulations of the laws of constant, multiple, and reciprocal proportion in chemistry, or of the laws of segregation, assortment, and linkage in genetics. Assuming, then, that it is a genuine law, how is it that today no one ventures to formulate this evolutional law in definite and quantitative terms?

Others, comprising, perhaps, a majority, prefer to distinguish between the fact and the causes of evolution. Practically all scientists, they aver, agree in accepting evolution as an established fact; it is only with reference to the agencies of evolution that controversy and uncertainty are permissible. To this contention one may justly reply that, by all the canons of linguistic usage, a fact is an observed or experienced event, and that hitherto no one in the past or present has ever been privileged to witness with his senses even so elemental a phenomenon in the evolutionary process as the actual origin of a new and genuine organic species. If, however, the admission be made that the term “fact” is here used in an untechnical sense to denote an inferred event postulated for the purpose of interpreting certain natural phenomena, then the statement that the majority of modern scientists agree as to the “fact” of evolution may be allowed to stand, with no further comment than to note that the formidable number and prestige of the advocates fail to intimidate us. Considerations of this sort are wholly irrelevant, for in science no less than in philosophy authority is worth as much as its arguments and no more.

The limited knowledge of the facts possessed by the biologists of the nineteenth century left their imaginations perilously unfettered and permitted them to indulge in a veritable orgy of theorizing. Now, however, that the trail blazed by the great Augustinian Abbot, Mendel, has been rediscovered, work of real value is being done with the seed pan, the incubator, the microtome, etc., and the wings of irresponsible speculation are clipped. Recent advances in this new field of Mendelian genetics have made it possible to subject to critical examination all that formerly went under the name of “experimental evidence” of evolution. Even with respect to the inferential or circumstantial evidence from palæontology, the enormous deluge of fossils unearthed by the tireless zeal of modern investigators has annihilated, by its sheer complexity, the hasty generalizations and facile simplifications of a generation ago, forcing the adoption of a more critical attitude. Formerly, a graded series of fossil genera sufficed for the construction of a “palæontological pedigree”; now, the worker in this field demands that the chain of descent shall be constructed with species, instead of genera, for links—“Not till we have linked species into lineages, can we group them into genera.” (F. A. Bather, Science, Sept. 17, 1920, p. 264.) This remarkable progress in scientific studies has tended to precipitate the crisis in evolutionary thought, which we propose to consider in the present chapter. Before doing so, however, it will be of advantage to formulate a clear statement of the problem at issue.

Evolution, or transformism, as it is more properly called, may be defined as the theory which regards the present species of plants and animals as modified descendants of earlier forms of life. Nowadays, therefore, the principal use of the term evolution is to denote the developmental theory of organic species. It is, however, a word of many senses. In the eighteenth century, for example, it was employed in a sense at variance with the present usage, that is, to designate the non-developmental theory of embryological encasement or preformation as opposed to the developmental theory of epigenesis. According to the theory of encasement, the adult organism did not arise by the generation of new parts (epigenesis), but by a mere “unfolding” (evolutio) of preëxistent parts. At present, however, evolution is used as a synonym for transformism, though it has other meanings, besides, being sometimes used to signify the formation of inorganic nature as well as the transformation of organic species.

Evolution, in the sense of transformism, is opposed to fixism, the older theory of Linné, according to whom no specific change is possible in plants and animals, all organisms being assumed to have persisted in essential sameness of type from the dawn of organic life down to the present day. The latter theory admits the possibility of environmentally-induced modifications, which are non-germinal and therefore non-inheritable. It also admits the possibility of germinal changes of the varietal, as opposed to the specific, order, but it maintains that all such changes are confined within the limits of the species, and that the boundaries of an organic species are impassable. Transformism, on the contrary, affirms the possibility of specific change, and assumes that the boundaries of organic species have actually been traversed.

What, then, is an organic species? It may be defined as a group of organisms endowed with the hardihood necessary to survive and propagate themselves under natural conditions (i.e. in the wild state), exhibiting a common inheritable type, differing from one another by no major germinal difference, perfectly interfertile with one another, but sexually incompatible with members of an alien specific group, in such wise that they produce hybrids wholly, or partially, sterile, when crossed with organisms outside their own specific group.

David Starr Jordan has wisely called attention to the requisite of viability and survival under natural conditions. “A species,” he says, “is not merely a form or group of individuals distinguished from other groups by definable features. A complete definition involves longevity. A species is a kind of animal or plant which has run the gauntlet of the ages and persisted.... A form is not a species until it has ‘stood.’” (Science, Oct. 20, 1922, p. 448.)

Sexual (gametic) incompatibility as a criterion of specific distinction, presupposes the bisexual or biparental mode of reproduction, namely, syngamy, and is therefore chiefly applicable to the metista, although, if the view tentatively proposed by the protozoölogist, E. A. Minchin, be correct, it would also be applicable to the protista. According to this view, no protist type is a true species, unless it is maintained by syngamy (i.e. bisexual reproduction)—“Not until syngamy was acquired,” says Minchin, “could true species exist among the Protista.” (“An Introduction to the Study of the Protozoa,” p. 141.)

To return, however, to the metista, the horse (Equus caballus) and the ass (Equus asinus) represent two distinct species under a common genus. This is indicated by the fact that the mule, which is the hybrid offspring of their cross, is entirely sterile, producing no offspring whatever, when mated with ass, horse, or mule. Such total sterility, however, is not essential to the proof of specific differentiation; it suffices that the hybrid be less fertile than its parents. As early as 1686, sterility (total or partial) of the hybrid was laid down by John Ray as the fundamental criterion of specific distinction. Hence Bateson complains that Darwinian philosophy flagrantly “ignored the chief attribute of species first pointed out by John Ray that the product of their crosses is frequently sterile in a greater or lesser degree.” (Science, Jan. 20, 1922, p. 58.)

Accordingly, the sameness of type required in members of the same species refers rather to the genotype, that is, the sum-total of internal hereditary factors latent in the germ, than to the phenotype, that is, the expressed somatic characters, viz. the color, structure, size, weight, and all other perceptible properties, in terms of which a given plant or animal is described. Thus it sometimes happens that two distinct species, like the pear-tree and the apple-tree, resemble each other more closely, as regards their external or somatic characters, than two varieties belonging to one and the same species. Nevertheless, the pear-tree and the apple-tree are so unlike in their germinal (genetic) composition that they cannot even be crossed.

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