The theory of Evolution was without a doubt one of most influential scientific theories in the culture of the 19th century, and it remains to this day the dominant theory, at least within the biological sciences. At the same time, however, and perhaps by reason of its longevity, no other theory has seen the devotees and the pillars which upheld it crumble to the same degree over the course of the years. As of today, evolutionism, by virtue of the advancement of studies in all correlated disciplines – from genetics to molecular biology, to paleontology, etc. – could be defined, without fear of exaggerating, as a theory now defunct, which survives exclusively in scholastic texts and in the books of those academics who still dare to defend it, albeit with a thousand caveats, a thousand ifs and buts.
Already from the beginning, from the publication of Charles Darwin’s The Origin of Species, the theory could claim illustrious critics of great scientific and philosophical depth. By the time of Darwin, works had already been published by the great men of morphological biology, which is to say, by the champions of that philosophical tradition which only later became scientific – a tradition dating back to Aristotle, which reads the transformations of life in the light of form rather than in adaptation by natural selection. After Aristotle, these great thinkers of life respond to the names of Linnaeus, Cuvier, Saint-Hilaire, Goethe, Von Baer and, at the beginning of the 20th century, D’Arcy Thompson, Kleinschmidt, Dacqué, Westenhöfer, Portmann, Sacchetti in Italy, and, in more recent times, also in Italy, Giuseppe Sermonti (among the advocates of the Structuralists of Osaka group), and Roberto Fondi, a paleontologist from Siena – only to name the foremost of them. Before passing over to analysis of the question, it is necessary, however, to clear the field of a number of prejudices which are to be found even amongst academics, and which hinder calm and constructive scientific debate. In the first place, as of today, all the polemics and debates on this issue seem to be reducible to a true ideological disagreement between the hard-line creationists, or, as we might define them, the fundamentalists of creationism, and the pure evolutionists, meaning those who sustain the modern version of Darwinism, so-called Neo-Darwinism – which is to say, Darwin enriched by the discovery of DNA.
There are some who exclude themselves from the aforementioned debate, and sometimes intentionally: namely, those who do not critique Darwinism from the point of view of the Biblical version of creation, but rather who, after clearing the field of every preconceived assumption, abide strictly by the facts issuing from scientific observation; and these facts recount a story entirely different both from the story of creation in seven days and also from that of evolution by trial and error over the period of hundreds of millions of years. Which is the same as saying that, beyond adaptation and selection (of which we will speak shortly), there exists an internal law in nature, as rigorous as any physical law, which passes, by means both of general models (the great group of the living) and also by the law of development, from one group to another; and it does so without having recourse to joining links and probabilistic hypotheses which are absolutely devoid of any non-scientific epistemological foundation.
But let us begin at the beginning, with Darwin himself. Certainly not everyone has read his classic works, such as The Origin of Species or The Descent of Man, and among those who have read these, few will have lingered over those parts in which Darwin himself indicates the difficulties and the possible objections to his theory.
The classic theory of Darwin maintains that in nature there exists a struggle without quarter among living species, a struggle in which only the most gifted and best adapted survive, and that in addition the individuals of living species are subject to accidental variations which might be advantageous or disadvantageous to them. Those variations which are advantageous help the affected individual to survive and are preserved in future generations via reproduction. Those which are disadvantageous, on the other hand, are simply eliminated insofar as the affected individual succumbs. This mechanism is called natural selection. According to this assumption, a species transforms itself or generates another species through a series of infinitesimal changes over the course of thousands of generations, and so, by rigorous logic, one should find in fossil deposits and also among living species all intermediate gradations. But of such gradations amongst living organisms, there is not so much as a shadow, and amongst fossils one observes precisely the same situation, to the point that the great palaeontologist and evolutionary biologist Stephen Jay Gould was pressed to speak of punctuated equilibrium: according to this theory living species are very stable and long-lived ‘Darwinian individuals’1 which appear or become extinct in the course of very few generations (therefore ‘unexpectedly’ from the perspective of geological time), leaving scarce trace, or no trace at all, of the passage from one species to the next. Here gradualism finds its gravestone and its obituary notice at the hand of one of the ‘authorized personnel’. As for punctuated equilibrium – we will have reason to return to this concept when the moment comes to draw the conclusions of our discourse.
At the time of Darwin, one knew nothing of genes, nor of which mechanism might be able to generate individual variation, and palaeontological research in those days was still patchwork. Indeed, only a few decades before, Cuvier and Saint-Hilaire had begun to disinter the creatures of the past, and Darwin therefore attributed the ‘missing links’, or, we would do better to call them, intermediate varieties, to the yet scarce advance in those excavations and in their findings. Notwithstanding this hope, Darwin did not fail to underline how this was a potentially lethal difficulty for his theory. Here are Darwin’s perplexities on this matter: ‘Why, if species have descended from other species by fine gradations, do we not everywhere see innumerable transitional forms? Why is not all nature in confusion, instead of the species being, as we see them, well defined?’ (The Origin of Species, Chapter VI, ‘Difficulties on Theory’); ‘But, as by this theory innumerable transitional forms must have existed, why do we not find them embedded in countless numbers in the crust of the earth?’ (Ibid.); ‘Lastly, looking not to any one time, but at all time, if my theory be true, numberless intermediate varieties, linking closely together all the species of the same group, must assuredly have existed; but the very process of natural selection constantly tends, as has been so often remarked, to exterminate the parent forms and the intermediate links. Consequently evidence of their former existence could be found only among fossil remains, which are preserved, as we shall attempt to show in a future chapter, in an extremely imperfect and intermittent record’ (Ibid.).
After 150 years, Darwin’s fear has become a reality, and the theory of punctuated equilibrium bears witness to this. But we will see that this latest theory, too, is nothing other than an extreme attempt to salvage an entire theory, an entire vision of the world.
In this same chapter, Darwin does not fail to observe also another problematic fact: namely, that the varieties of one and the same species might crossbreed, giving origin to fertile offspring, while if species crossbreed, although belonging to the same biological group, they give life only to sterile offspring (Horse-Donkey; Tiger-Lion, etc.); in practice the species are hermetically separate from each other, and a hypothetical intermediary form, with intermediary characteristics between two species perfectly adapted to their habitats, would be destined to disappear. One imagines in fact a being which is no longer quadruped but not yet capable of flight, or worse a quadruped which is on the road to becoming a cetacean. This intermediary species, moreover, would find itself being a variety as much of the species from which it originated as of that toward which it is heading, and could, therefore, crossbreed with both; but these meanwhile could not crossbreed with one another, for if they could the two species would not be any longer two, but rather one (a logical contradiction!). Darwin, being the serious scientist he was, was well aware of this.
Another problem which Darwin also confronted is that which we might call, using a modern term which has been borrowed by scholars near to the milieu of the American evangelical creationists, irreducible complexity.2 That is to say, the existence of organs and structures of such complexity that they exclude any thought of mutation and gradual adjustments. Indeed: ‘If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down’ (Ibid.).
And in fact there do exist structures such as the eye, or the wings of birds, which are difficult to imagine as the products of a series of trials and errors. But we will treat of this question after we have attained a more favourable point of view. Yet another question from the endless number treated by Darwin is that inherent in the concept of utility. The theory of evolution is evidently strongly centred on this concept. Indeed, that which renders a mutation favourable is precisely its utility toward the end of survival, and therefore all living structures, without any exception, must have either an immediate or a hidden utility. And thus, as Darwin admits, if there existed even a single structure without observable utility, or else a structure which was simply ‘beautiful’, and, we would be tempted to say, artistic, the theory of evolution would suffer another heavy blow. Speaking of the detractors of utilitarianism, Darwin indeed affirms: ‘They believe that many structures have been created for the sake of beauty, to delight man or the Creator (but this latter point is beyond the scope of scientific discussion), or for the sake of mere variety, a view already discussed. Such doctrines, if true, would be absolutely fatal to my theory’ (Ibid.).
In this passage, Darwin admits how lethal such an eventuality could be for his theory, but he nonetheless appears sceptical as to its universal diffusion and universality. Very different is his opinion in a later work (The Descent of Man, Chapter IV):
I now admit … that in the earlier editions of my ‘Origin of Species’ I probably attributed too much to the action of natural selection or the survival of the fittest. I have altered the fifth edition of the Origin so as to confine my remarks to adaptive changes of structure. I had not formerly sufficiently considered the existence of many structures which appear to be, as far as we can judge, neither beneficial nor injurious; and this I believe to be one of the greatest oversights as yet detected in my work.
Such an affirmation is important for two reasons. In the first place, Darwin recognizes that there exist many of those structures, whose existence he judged to be fatal for his theory, and this demonstrates both Darwin’s scientific honesty, but also the enormity of the difficulty before which he found himself. Moreover – and this is the crux of the question – he realizes that he has attributed, precisely in spite of the existence of a great many neutral structures, an excessive importance to natural selection and to the survival of the best adapted. Here we find ourselves before two orders of problems. The first: If variety is in large part neutral, on what material would natural selection operate? It is evident that without advantageous and disadvantageous variations selection is completely useless. In the second place: What is the origin of variety, both intra-species and inter-species? To the first question one can respond simply that selection does not operate and so cannot be the cause of variety. But since variety exists and the species are perfectly adapted to their habitat, evidently all this must have another cause. But before being a scientific problem, natural selection is a philosophical problem. By the admission of Darwin himself, his theory was born, among other things, along the lines immediately successive to the step cited above in The Descent of Man – precisely as the reaction to the doctrine of separate creations and of final causes; that is, from the need to eliminate causes external to nature itself. But precisely natural selection constitutes such a cause, because in order to effect a selection there is need of a cause which ‘knows’ which traits are advantageous and which are not, and which thus effects a ‘choice’ and above all has in view the end of such action: namely, to generate adapted beings. The problem is that beings adapt, but without selection, and variety is often not connected to any strictly adaptive problem.
Indeed, one tends ever more to speak, amongst the specialists, of allopatric speciation and genetic drift, or else of sympatric speciation and neoteny or paedomorphosis,3 as the cardinal processes of the phenomenon of differentiation and adaptation of living things. The first would occur when a small group of individuals of a species finds itself isolated in a context different from that place of origin in which the species, in its totality, naturally possessed a superior genetic wealth. Genetic drift is caused precisely by the scant number of individuals and thus by the greater probability that a single trait might acquire a predominance that it did not have in its land of origin, so that a trait might leap out from the assortment of genes, which in the entire population was recessive and silent. Let us take the example of a sack of beans. If one sack contains a thousand beans, white and red in equal number, and if we take out ten at random, choosing from the entire sack, there will be more or less the same probability of taking out red and white ones in equal number. The case will be otherwise if we reduce the choice to five hundred and then to one hundred, then fifty. The fewer the beans, the lower the probability that the two traits appear equally, and the higher the probability that for example nine red and one white, or all red, will come out. The low number introduces an element of instability but, we would add, also of impoverishment. In reality, genetic drift only generates varieties or makes traits explicit which were already innate in the genetic patrimony of the species; but it does not create new genes and thus new structures. The second form of speciation is that which involves animals in a land of origin which is enriched by neoteny (for its importance, we will explore neoteny more in depth afterward). Practically speaking, in the originating land of a species there would be a greater assortment of genes and therefore a greater number of possible combinations, and thus of responses to the ecological situation and to environmental strains. However, the lack of transitional forms or groups of transitions has pressed many Biologists (Schindewolf, Goldschmidt, Dalcq, for example) to posit that the species might be born following exceptional events such as a blockage to development at the fetal stage, thus during the least specialized stage, and to generalized mutations which might lead therefore to the appearance of adults which are profoundly different. However these mutations cannot be accidental, seeing as how, in order for a flying animal which is capable of surviving, for instance, to be born from a terrestrial animal, the series of mutations must be immediate, effective and finalized. Or else one thinks of the passage from the simple egg of fish and amphibians to the amniotic egg with rigid shell of Reptiles and Birds (or of monotreme Mammals). Mere accident cannot have part in such a process. Such biologists, moreover, do not specify what type of mutations we are dealing with, and in what way these might possibly be different from those known to genetics. Evidently the explanations furnished by the ‘authorized personnel’, both Darwinist and Neo-Darwinist, cannot satisfy the natural search for causes which distinguishes humanity as such.
But, before touching on the molecular and genetic details pertinent to our argument, it would be well for us to broadly characterize the debate of the 19th century on the origin of variety in living things. In our opinion, three great figures stand out from all the others, and characterize the archetypal ideas amongst which the most varied gradations might be found: George Cuvier, Geoffroy Etienne de Saint-Hilaire, and Johann Wolfgang von Goethe. Cuvier can be considered the father of comparative anatomy and of that discipline which studies fossils. He was the first to realize that there does not exist any continuity between fossilized strata and thus between the creatures that had lived in the corresponding periods. He imputed this discontinuity to a series of catastrophes which he believed had struck the Earth from time to time in distant epochs, and also to the arrival in the areas struck by cataclysms of new species originating in other areas; and therefore not, as had erroneously been believed, to successive creations. But this is only a single detail of his biological ideas. Cuvier, following and developing the ideas of Aristotle, as they were presented in the collection On the Parts of the Animals, understood how the living species follow precise principles of organic development – principles, we might say, which are logical before being biological. And indeed we read in Article IV of the first of the Lessons on Comparative Anatomy, 1836 edition:
In fact, there is not any function which does not require the aid and concurrence of almost all the others, and which does not more or less feel the effect of their degree of energy.
Respiration, for instance, cannot operate save with the aid of the movements of the blood, since it consists in nothing more than the reconciliation of this fluid with the surrounding element; so that, just as it is circulation which sets the blood into motion, blood is, so to speak, a necessary means for obtaining respiration.
Circulation itself has its cause in the muscular action of the heart and of the arteries; it does not operate therefore save by the aid of irritability. This, in turn, draws its origin from the nervous fluid, and consequently from the function of sensitivity, which, in a kind of circle, stems from the circulation, the cause of all secretions, both of nervous fluid and of all the others.
What would become of sensitivity, if the muscular force did not come to its aid even in the most minute circumstances? What good would the sense of touch be, if one could not carry one’s hand toward palpable objects? And how would one see, if one could not turn one’s head and one’s eyes at will?
It is in this mutual dependence of functions and in the aid which they reciprocally bring each other, that the laws which determine the relations of the organs are founded, and these laws are of the same necessity as the laws of metaphysics and mathematics. Indeed it is evident that the appropriate harmony amongst the organs which act on one another, is one of the necessary conditions for the existence of the being to which they belong, and if any one of the functions were modified in any way incompatible with the modifications of the others, the being in question could no longer exist.
So, according to Cuvier, there are certain laws, as necessary as those of Metaphysics and of Mathematics, which uphold the relationship between the parts, and also the relationship between the parts and the whole. Indeed, further on Cuvier writes:
Thus an animal which cannot digest anything but flesh must possess, on pain of the destruction of its species, the capacity to perceive its prey, to pursue it, to seize it, to overpower it, to dismember it. It must therefore be, by force of necessity, piercing in its vision, keen of smell, swift of foot, dexterous and strong in its paws and in its jaws. Sharp teeth for cutting flesh would therefore never coexist in the same species together with a foot enveloped with corns, which cannot do other than hold the animal up, and with which the animal is unable to grab onto anything. Whence the rule by which all hoofed animals are herbivores; and also those yet more detailed rules, which are naught but the corollaries of the first, that hooves on feet imply molars with flat crowns, a very long alimentary tract, ample and multiple stomachs, and a great number of relations of the same kind.
And in a yet more stringent manner in the ‘Preliminary Discourse’ of Studies on the Fossilized Bones of Quadrupeds, of 1812:
Happily, comparative anatomy possessed a principle which was capable, if well developed, of dissolving all these embarrassments: that was the principle of the correlation of forms within organized beings, by means of which each kind of being could rigorously be recognized through each fragment of each of its parts.
The entire organized being forms an ensemble, a unique and closed system, whose total parts correspond mutually to one another, and converge in response to the same definitive action through a reciprocal reaction. Not one of these parts can change save as the others change as well; and consequently each of them, taken separately, indicate and yield all the others. …
In a word, the form of a tooth implies the form of a condyle, and also that of the scapula, of the fingernails or claws, just as the equation of a curve contains all of its properties. And just as by taking each of a curve’s properties separately as the base of a particular equation, one rediscovers both the ordinary equation and all its other peculiar properties, so the very fingernail or claw, the scapula, the condyle, the femur, and all the other bones taken each separately, yield the tooth, or they yield each other reciprocally; and commencing with each if them individually, whoever rationally possesses the law of organic economy could reconstruct the entire animal.
Cuvier’s principle, bold as it is efficacious, is to look at the science of organic nature with the same rigour with which a mathematician regards curves and their respective equations. Cuvier was actually capable, to the amazement of his students and contemporaries, of proceeding from the mere molar of a Mastodon or a Mammoth to the general form of the animal, demonstrating a truly prodigious mastery and an extraordinary knowledge of the laws of organic economy. But what is yet more important is the conviction that the organism was a whole and that the correlation of the parts was comprehensible only by departing from this unity of ends which all organic forms display.
Saint-Hilaire, nearly contemporaneous with Cuvier and in a certain sense his antagonist, sustained the same principle of unity and harmony of organic organization; but while for Cuvier this unity and harmony submerged their roots in principles and laws extrinsic to the very organic world to which the organism must become uniform if it wishes to conserve itself, for Saint-Hilaire the living organism possesses a principle of internal organization, an intrinsic law, an ideal principle, identical for all animals, which, though conditioned in a certain degree by external conditions and by the laws of inorganic nature, possesses however its own peculiar mode of responding to the strains of the environment, and also certain laws proper to it. Indeed already in his contribution to the Magasin Encyclopédique of 1796 (Vol. VII, p. 20), Saint-Hilaire sustains:
If we consider one particular class of animals, here especially the plan of that class will appear evident to us: we will find that all its different forms…all derive from one another: it suffices to change some one or other of the proportions of the organs to render them appropriate for new functions, or to extend or to restrain their uses.
Thus it is evident, already from this brief passage, that Saint-Hilaire admits the transformation of the species from one species into another, but only departing from the general model of an animal class, for example, let us say of mammals, and from a law of development which he defines as the unity of the organic composition, and which has four cornerstones: the law of analogy, the law of connection between the parts, the law of elective affinity between organic elements, and the law of equilibrium between the organs.4 The first tells us that the great organic groups are dominated, between each other and within themselves, by the law of analogy, and possess therefore structures and functions which are analogous (although, we would be tempted to add, not homologous; but we will shortly return to the difference between homology and analogy); for example the gills of fish and the lungs of terrestrial tetrapods have the same function even if in different elements and with a different genetic origin (indeed, the lungs of terrestrial tetrapods are probably alike, genetically speaking, to the swim bladder of fish, and so are homologous organs)5 and so are organs with equal function but different derivation. Or else the structure of the ‘hand’ of the tetrapods; these are always pentadactyl, and their bones, albeit with modifications of volume, form, etc., conserve reciprocal positions and relations.6 The law of connection between the parts states that the parts of animals have constant relations, even if in different proportions or with different uses depending on the species. For example, in the forelimbs of Vertebrates, the bones have a constant relation between themselves, even if in some species certain segments are emphasized, and others in other species: in man, for example, the arm and forearm predominate with respect to the hand, which however is very versatile and has free phalanges, while in cetaceans the hand is enormous and humeral, the radius and ulna are very short, and together with the phalanges, which are often much lengthened, are incorporated in the connective tissue to form a paddle; in birds, the third finger alone is developed and it is lengthened to form the carrying structure of the wing, while the other phalanges are reduced to vestiges. Notwithstanding such variety the relation between bones remains constant.
The law of elective affinity of the parts states that some parts or organs are linked by a thread or by a principle, according to which any variation of the one brings variation in the other; for example the relation between the forelimbs and the hind limbs always remains constant, so that the more the first develop the more the others regress; or else between the neck and the rest of the body, the longer the neck the shorter the body (Giraffe, Flamingo), or the limbs and the tail (in Serpents, for example, the limbs have disappeared and the animal has become ‘entirely tail’).
The preceding principle directs us toward the fourth, the law of equilibrium between the masses of the organs. Hence for example the law that establishes that all the animals with horns cannot have a complete set of teeth on their jawbone, so that bovids and cervids lack incisors on their jaw, and their canines, such as they are, are much reduced or disappear. Camelids on the other hand do not have horns, but have longer necks and limbs and two incisors on their jaw, and have moreover a stomach composed in a way similar to that of ruminants with true and proper horns. There thus stands a relation between horns, teeth, and appendices on one hand and digestive systems on the other (a relation already noticed by Aristotle).
All of this strongly anticipates what was to become the theory of type and unity of Type and the principle of Metamorphosis of Goethe, which will be the object of the following pages.
1Here, evidently, attention is shifted from the biological individual, object of classic Darwinism, to the species seen as the subject of the evolutionary process.
2Michael Behe of the University of Leighton (Pennsylvania), for example.
3Stephen Jay Gould, Ontogeny and Phylogeny.
4Etienne Geoffroy de Saint-Hilaire, Philosophie Anatomique, vol.2, ‘Discourse preliminaire’, pp. 31–34.
5Both the lungs and the swim bladder, embriologically, are an eversion of the esophagus on the pharyngeal level; gills are rather a derivation of the pharyngeal pits, which then give origin to the larynx and to the trachea in superior vertebrates.
6In reality the distinction between analogy and homology is not so stringent as it might seem. Indeed, one would expect for instance that the hand of tetrapods were assembled from one and the same group of genes, but this isn’t always the case; and also vice versa, organs, functions or different proteins are often assembled in different organisms by the same genes. In fact one speaks even of Ortologous and Paralogous genes: that is, respectively, a gene which generates two others independent each other, or else generates two by way of splitting. In such a case it would be perhaps necessary to coin a fitting term and to speak at most of morpho-genetic analogy and homologous heterogenesis (genetic in Goethe’s sense, as we will soon see).
Excellent article. Well worth translating and a subject with many implications.