Section D—Chairman's Address
On the Survival of Traditional Themes in Biological Thought
In a few years, we shall celebrate the centenary of the publication of Darwin's “Origin of species,” and so bring to a close a century which in our view has been the most significant in the history of biological thought. We will then, and properly so, give tribute to a man and a work which by inspiring great efforts in researches into the proofs of evolution, debate on the origins of living things, and enquiry into the relationships and affinities of living things, shook asunder an accumulation of facts and opinion, but provided a new plan and pattern for a fresh assembly of data. If we search through the realm of human knowledge, I doubt that outside of the principles of mathematics we can find another concept which has had to carry such a heavy burden of additional information as has the Darwinian theory. Since it was stated, there has been tremendous expansion in systematics, morphology, embryology, physiology, biochemistry, and the establishment of genetics, ecology, and other relevant fields all contributing to biological knowledge and commonly investigated in terms of the Darwinian principles.
When a sculptor works in clay, he forms first a core or matrix which is a pattern to strengthen and maintain the final model. The sculptor adds clay piece by piece to the core, and so slowly forms the whole until with shaping and smoothing, the model stands complete. A mould is made from this model, and from the mould, a casting. The casting standing by its own strength, and without a core, becomes known as the sculptor's work. Now there is always danger in the use of examples such as that just given; but there is a parallel between a sculptor and his work, and Darwin and his theory. The example indicates that while the final form of the Darwinian theory is well-known, the core which was the framework and on which the theory was modelled is now largely lost from view as the centenary of the theory draws near. The example can be used a little further. If the sculptor completes his clay model, and then others keep adding clay piece by piece, for a time the model can be kept to some semblance of its original form, but gradually it becomes disproportionate, even grotesque, and finally exceeds the strength of the core to the point where the whole may even collapse.
The core for Darwin's theory was the knowledge and philosophies of his day. There was then a gross mechanistic outlook, a reaction to the final stages of an animistic vitalism. There was a firmly established particulate concept in physics and in chemistry. There was still much of the belief of the arrogant supremacy of man in the world about him, although there was strong reaction to the fading echo of traditional beliefs as set out in biblical writings. It is not possible in a brief paragraph to fully treat of the intellectual atmosphere of those times; still we can recognise some of its salient features and appreciate that the theory was not advanced by pure reason ab initio but
included acceptance of, or reaction to other theory and conjecture. It is this which is well worthy of examination to-day, for those who will accept the Darwinian theory without further fundamental enquiry must realise that they commit themselves to a theory built on a framework of the philosophies of that day and now required to support all the additional data from the following hundred years of active and greatly extended research.
When we examine the period preceding the statement of the Darwinian theory, we find that biological philosophy had progressed for a century and more in various attempts to graft a growing mass of data onto the principle of special creation. In this association of biological and theological philosophies, there were developed theories which were found adequate by many, sufficiently so that a scientist of the calibre of Linnaeus could utilise the concept of species stability and so found the study of systematics in the form in which we still essentially practise this art to-day. Creation and all the implications of creation could be applied with ease and propriety to the interpretation of a very wide range of facts. If one accepts the principle of creation, then it follows that there will be perfection in the structure and functions of the parts of animals and the animals will be suited to their surroundings. Likewise, imperfection will have the connotation of sin and it is proper that the imperfect organism will be destroyed, banished from the face of the earth. I feel I need not go further on these lines. All of us are aware that the distinct concept of evolution with all the connotations and the consequences from mutability appeared nearly forty years before the Darwinian theory and in a country often described as having a new great liberalism in thought, but it was essentially a country in which for the time being a social symbolism had displaced religion. The liberalism was not, as we might feel, a true freedom of thought; but a freeing of thought in which there was a strong bias against previous tenet.
It is not remarkable, then, that in such an atmosphere, the idea of evolution and of mutability should develop as the complete antithesis to the concept of creation, nor is it remarkable that the evolutionists of those times should seize on the evidences used by the creationist and turn that evidence against them and their theory. Not that this is so expressed in the writings of the early years of the nineteenth century; but the creationists had availed themselves of all possible data and there was little untouched by them which was available to the evolutionists. The two theories then had a common meeting ground in the facts, and the principles related to those facts, and so we come to find the remarkable carry-over of these facts and principles from the one theory to the other although the two theories were and remain completely opposed such that the one cannot stand unless the other is totally destroyed.
The evolutionist won the day and we accept his theory to the present time. We have discarded creation as an acceptable working hypothesis. We have thrown away the idea of immutability and committed ourselves to the principle of mutability. At the same time we adhere with little alteration in practice to the working principles of a Linnaean systematics which was based on immutability. This is well shown in the constant trend to the elevation of the “type-specimen” to a level far above any which is justified if we do accept fundamentally the concept of mutability. It is this ambivalence which is probably basic to our inability at this time to develop a concept of species in a single
form, with the result that we are in quandary when we attempt to evaluate a basic unit in the study of an animal species, population, or community.
Equally we encounter major difficulties when we endeavour to analyse the fundamental relationships of form and function. We need go no further back in written history than the Bible to see that if creation had taken place, then obviously living things would be created in a perfect or near perfect form. To consider otherwise would argue against creation and planned design. The principle of perfection must be accepted by the adherent to the creation theory. Such perfection can only exist when the animal as a whole fits to its place in nature and fills its purpose in the created scheme of things. Its parts will each show design to the function they perform. The early evolutionist was placed in the unfortunate circumstance that he was intellectually conditioned to an idea of perfection and suitability in nature. There was little debate as to whether such perfection did, or did not exist. Instead, there was substituted the concept that the perfection of the animal and of its parts was suited to the demands on the animal for the time being. Should circumstances change, so then could the animal change to suit the new requirement. Such of course must be the tenet of the evolutionist who rests no small part of his theory on the fact that environments change. It is proper that we recognise that the idea of perfection, or of adaptation as we now term it, is one of the greatest antiquity and has been adopted with little basic alteration in concept by the evolutionist. It was once a central theme for the vitalists, then for the mechanists, always for the creationists, and now for the evolutionists. These have each aimed to explain the achievement of adaptation in terms of their own concept. We, too, who are committed to evolution must hold as strongly as any creationist to the idea that all animals and all parts of the individual organism are analysable in terms of function, that the animal as we see it is completely adapted, and that from this we can determine and measure all structures in terms of positive values. It is in this gross form that we find this idea present in systematic work, in much morphology, fundamentally in much ecology; but many biologists will not carry the concept to the extreme form. I have indicated above. Adaptation does of course exist; but equally or even to a greater degree there is a non-adapted element in all living organisms, basic mechanisms and parts which have no unusual demand placed on them. There are possibly even non-adapted species. When we recognise this, we destroy the case for the creationists, weaken the case for the mechanists, but likewise we weaken parts of the case presented by the ardent Darwinian.
The above then deals briefly with two examples of pre-Darwinian themes which have persisted into modern biological thought and practice. Both are traditional in origin, developed to major status in pre-evolution times, adopted by the evolutionists as tools sharpened and turned against the creationists, and come to form an important part of the philosophical core or matrix for the Darwinian theory. Other such themes are not difficult to find. If perfection is created, then imperfection can only be an offence against creation, and as such warrants banishment. It is not difficult to substitute for a few words in that concept and arrive at the conclusions in the Darwinian theory. In the eighteenth century, after much serious consideration and investigation, the traditional belief in prenatal influence by environmental factors was recognised as false. The womb became a sanctuary from the influences of the world.
The transition from this to the theory of the stability of the germ plasm is a simple step to take when it is sought to demonstrate that variation stems from accidents in the development of the individual, and not from environmental influences. The list of such themes is too long to be detailed here; but as we examine more and more of them, it becomes clearer that what we have inherited is an anti-creation philosophy, which does not necessarily mean that we have gained a negative philosophy. It does mean that the philosophy we employ is the more acceptable philosophy so long as the choice lies only between creation and evolution.
In these latter terms, there is reason for the doubts that some modern biologists adopt in their attitude to the Darwinian theory. Much of the philosophical foundation for the theory is outmoded or seen at best as the reverse of the creationist theory. We are now sufficiently remote in time from the bitterness of controversy between the creationists and evolutionists. We are no longer involved in debate on vitalism and mechanism. There is the great wealth of new knowledge developed in the past one hundred years. In brief, we have an opportunity for real freedom of thought, and we have the material to work over. The neotenists and the macroevolutionists have carried the ideas of the mutationists a long step forward and discredited the biogenetic laws even as they were discredited before they were published by Haeckel. It is now amply demonstrated that the external environment can influence the child in the womb, and that the germ-cells, and even the germ-cell nucleus which is the last refuge of the Weismannists, are influenced by at least some environmental factors. We are gaining a valuable new insight from fresh thought in ecology which is showing us that structure and function are secondary to flexibility of behaviour in the maintenance of an animal in a changing environment. We have been enriched in our thought by many new philosophies especially those of emergent evolution and holism. It is hardly to be expected that in these circumstances we will abide by a theory which had its greatest adherence from the fact that it provided an acceptable mechanism to support a theory of evolution, in contrast to a theory of creation.
There is the opportunity now to consider that the past century has been concerned with only two possibilities: creation or evolution. Other possibilities have not been explored. We have been concerned with a situation in which the choice has been clear cut. It is possible that many of our major philosophical difficulties may be resolved if we seek out a third and different possibility. What form it will take, is difficult to see; but it is clear that we will not return to a creation concept. It is clear also that if we adhere to a concept of evolution we are compelled to the view that this demands a sequence from simplicity to complexity. Up until recent years, it was not difficult to rely on a belief that life commenced by the remarkable but still accidental appearance of a protein-like substance which gradually acquired the vital properties of assimilation, respiration, growth, etc. Now we can see that if we accept the almost impossible chance formation of a protein-like substance, the improbability of the necessary coincidental formation of even the simplest suitable enzyme system throws the whole conjecture beyond any reach of credibility. Even if we reduce the system to the absolute minimum, a light-active substance capable of synthesis from inorganic material, we tend immediately to select a carbon dioxide cycle with quick energy turnover and little possibility for protein
synthesis, although the latter may be a subsequent development. At the moment, it is not unfair to say that our knowledge is now such that it is well-nigh impossible to hold to a concept of evolution which would demand an origin of life from a chemical accident, a theme which is repeated in the “purposeless progress of Darwinian evolution through accidental variation.” Now, if we are unable to provide a reasonable and acceptable “origin for life” to fit in with the concept of evolution, it is obvious that we must either develop a theme differing from that of evolution, or bow our heads to the victory of the creationists.
This latter step should not be necessary so long as we do not bind ourselves in unwarranted adherence to a concept of evolution and a theory of evolutionary mechanisms which came into being in opposition to long-held traditional ideas, and which may now have served their purpose in giving us a freedom from tradition so that we may explore and discover an unbiased understanding of the nature and relationships of life on this earth.