The case against evolution

by George Barry O'Toole

When we speak of persistent types, we mean generic and specific, rather than phyletic, types, although it is assuredly true that the persistence of the great phyla, from their abrupt and contemporaneous appearance in Cambrian and pre-Cambrian rocks down to the present day, constitutes a grave difficulty for progressive evolution in general and monophyletic evolution in particular. All the great invertebrate types, such as the protozoa, the annelida, the brachiopoda, and large crustaceans called eurypterids, are found in rocks of the Proterozoic group, despite the damaged condition of the Archæan record, while in the Cambrian they are represented by a great profusion of forms. “The Lower Cambrian species,” says Dana, “have not the simplicity of structure that would naturally be looked for in the earliest Palæozoic life. They are perfect of their kind and highly specialized structures. No steps from simple kinds leading up to them have been discovered; no line from the protozoans up to corals, echinoderms, or worms, or from either of these groups up to brachiopods, mollusks, trilobites, or other crustaceans. This appearance of abruptness in the introduction of Cambrian life is one of the striking facts made known by geology.” (“Manual,” p. 487.) Thus, as we go backward in time, we find the great organic phyla retaining their identity and showing no tendency to converge towards a common origin in one or a few ancestral types. For this reason, as we shall see presently, geologists are beginning to relegate the evolutionary process to unknown depths below the explored portion of the “geological column.” What may lurk in these unfathomed profundities, it is, of course, impossible to say, but, if we are to judge by that part of the column which is actually exposed to view, there is no indication whatever of a steady progression from lower, to higher, degrees of organization, and it takes all the imperturbable idealism of a scientific doctrinaire to discern in such random, abrupt, and unrelated “origins” any evidence of what Blackwelder styles “a slow but steady increase in complexity of structure and in function.” (Science, Jan. 27, 1922, p. 90.)

But, while the permanence of phyletic types excludes progress, that of generic and specific types excludes change, and hence it is in the latter phenomenon, especially, that the theory of transformism encounters a formidable difficulty. Palæobotany furnishes numerous examples of the persistence of unchanged plant forms. Ferns identical with the modern genus Marattia occur in rocks of the Palæozoic group. Cycads indistinguishable from the extant genera Zamia and Cycas are found in strata belonging to the Triassic system, etc., etc.

The same is true of animal types. In all the phyla some genera and even species have persisted unchanged from the oldest strata down to the present day. Among the Protozoa, for example, we have the genus Globigerina (one of the Foraminifera), some modern species of which are identical with those found in the Cretaceous. To quote the words of the Protozoologist, Charles A. Kofoid: “The Protozoa are found in the oldest fossiliferous rocks and the genera of Radiolaria therein conform rather closely to genera living today, while the fossil Dinoflagellata of the flints of Delitzsch are scarcely distinguishable from species living in the modern seas. The striking similarities of the most ancient fossil Protozoa to recent ones afford some ground for the inference that the Protozoa living today differ but little from those when life was young.” (Science, April 6, 1923, p. 397.)

The Metazoa offer similar examples of persistence. Among the Cœlenterata, we have the genus Springopora, whose representatives from the Carboniferous limestones closely resemble some of the present-day reef builders of the East Indies. Species of the brachiopod genera Lingula and Crania occurring in the Cambrian rocks are indistinguishable from species living today, while two other modern genera of the Brachiopoda, namely, Rhynchonella and Discina, are represented among the fossils found in Mesozoic formations. Terebratulina striata, a fossil species of brachiopod occurring in the rocks belonging to the Cretaceous system, is identical with our modern species Terebratulina caput serpentis. Among the Mollusca such genera as Arca, Nucula, Lucina, Astarte, and Nautilus have had a continuous existence since the Silurian, while the genera Lima and Pecten can be traced to the Permian. One genus Pleurotomaria goes back to pre-Cambrian times. As to Tertiary fossils, Woods informs us that “in some of the later Cainozoic formations as many as 90 per cent of the species of mollusks are still living.” (“Palæontology,” 1st ed., p. 2.) Among the Echinodermata, two genera, Cidaris (a sea urchin) and Pentacrinus (a crinoid) may be mentioned as being persistent since the Triassic (“oldest” system of the Mesozoic group). Among the Arthropoda, the horseshoe crab Limulus polyphemus has had a continuous existence since the Lias (i.e. the lowest series of the Jurassic system). Even among the Vertebrata we have instances of persistence. The extant Australian genus Ceratodus, a Dipnoan, has been in existence since the Triassic. Among the fossils of the Jurassic (middle system of the Mesozoic group), Sharks, Rays, and Chimaeroids occur in practically modern forms, while some of the so-called “ganoids” are extremely similar to our present sturgeons and gar pikes—“Some of the Jurassic fishes approximate the teleosts so closely that it seems arbitrary to call them ganoids.” (Scott.)

The instances of persistence enumerated above are those acknowledged by evolutionary palæontologists themselves. This list could be extended somewhat by the addition of several other examples, but even so, it would still be small and insufficient to tip the scales decisively in favor of fixism. On the other hand, we must not forget that the paucity of this list is due in large measure to the fact that our present method of classifying fossiliferous strata was deliberately framed with a view to excluding formations containing modern types from the category of “ancient” beds. Moreover, orthodox palæontology has minimized the facts of persistence to an extent unwarranted even by its own premises. As the following considerations indicate, the actual number of persistent types is far greater, even according to the evolutionary time-scale, than the figure commonly assigned.

First of all, we must take into account the deplorable, if not absolutely dishonest, practice, which is in vogue, of inventing new names for the fossil duplicates of modern species, in order to mask or obscure an identity which conflicts with evolutionary preconceptions. When a given formation fails to fit into the accepted scheme by reason of its fossil anachronisms, or when, to quote the words of Price, “species are found in kinds of rock where they are not at all expected, and where, according to the prevailing theories, it is quite incredible that they should be found ... the not very honorable expedient is resorted to of inventing a new name, specific or even generic, to disguise and gloss over the strange similarity between them and the others which have already been assigned to wholly different formations.” (“The New Geology,” p. 291.) The same observation is made by Heilprin. “It is practically certain,” says the latter, “that numerous forms of life, exhibiting no distinctive characters of their own, are constituted into distinct species for no other reason than that they occur in formations widely separated from those holding their nearest kin.” (“Geographical and Geological Distribution of Animals,” pp. 183, 184.) An instance of this practice occurs in the foregoing list, where a fossil brachiopod identical with a modern species receives the new specific name “striata.” Its influence is also manifest in the previously quoted apology of Scott for calling teleost-like fish “ganoids.”

We must also take into account the imperfection of the fossil record, which is proved by the fact that most of the acknowledged “persistent types” listed above “skip” whole systems and even groups of “later” rocks (which are said to represent enormous intervals of time), only to reappear, at last, in modern times. It is evident that their existence has been continuous, and yet they are not represented in the intervening strata. Clearly, then, the fossil record is imperfect, and we must conclude that many of our modern types actually did exist in the remote past, without, however, leaving behind any vestige of their former presence.

Again, we must frankly confess our profound ignorance with respect to the total number and kinds of species living in our modern seas. Hence our conventional distinction between “extinct” and “extant” species has only a provisory value. Future discoveries will unquestionably force us to admit that many of the species now classed as “extinct” are in reality living forms, which must be added to our list of “persistent types.” “It is by no means improbable,” says Heilprin, “that many of the older genera, now recognized as distinct by reason of our imperfect knowledge concerning their true relationships, have in reality representatives in the modern sea.” (Op. cit. pp. 203, 204.)

Finally, the whole of our present taxonomy of plants and animals, both living and fossil, stands badly in need of revision. Systematists, as we have seen in the second chapter, base their classifications mainly on what they regard as basic or homologous structures, in contradistinction to superficial or adaptive characters. Both kinds of structure, however, are purely somatic, and somatic characters, as previously observed, are not, by themselves, a safe criterion for discriminating between varieties and species. In the light of recent genetical research, we cannot avoid recognizing that there has been far too much “splitting” of organic groups on the basis of differences that are purely fluctuational, or, at most, mutational. Moreover, the distinction between homologous and adaptive structures is often arbitrary and largely a matter of personal opinion, especially when numerous specimens are not available. What the “Cambridge Natural History” says in allusion to the Asteroidea is of general application. “While there is considerable agreement,” we read, “amongst authorities as to the number of families, or minor divisions of unequivocal relationship, to be found in the class Asteroidea, there has been great uncertainty both as to the number and limits of the orders into which the class should be divided, and also as to the limits of the various species. The difficulty about the species is by no means confined to the group Echinodermata; in all cases where the attempt is made to determine species by an examination of a few specimens of unknown age there is bound to be uncertainty; the more so, as it becomes increasingly evident that there is no sharp line to be drawn between local varieties and species. In Echinodermata, however, there is the additional difficulty that the acquisition of ripe genital cells does not necessarily mark the termination of growth; the animals can continue to grow and at the same time slightly alter their characters. For this reason many of the species described may be merely immature forms....

“The disputes, however, as to the number of orders included in the Asteroidea proceed from a different cause. The attempt to construct detailed phylogenies involves the assumption that one set of structures, which we take as the mark of the class, has remained constant, whilst the others which are regarded as adaptive, may have developed twice or thrice. As the two sets of structures are about of equal importance it will be seen to what an enormous extent the personal equation enters in the determination of these questions.” (Op. cit., vol. I, pp. 459, 460.)