The present position of the Darwinian theory.

Abstract

And there arose another king that knew not Joseph. must be admitted that the Darwinian theory of evolution by natural selection has fallen upon evil days. Prominent literary men like G.K. Chesterton have allowed themselves to talk of the dead dogma of Darwinism. Although the connotation of Darwinism in the minds of such emotional and inexact writers is somewhat obscure, nevertheless they reflect an impression which they have imbibed from scientific acquaintances, viz. that our views on many things connected with life have changed since Darwin's time, and that most of Darwin's arguments will no longer hold. They cannot be blamed for conceiving this idea, for to a hearer of the discussion on evolution which took place last September at the meeting of the British Association at Hull (1), it must have seemed clear that many zoologists and botanists were inclined to deny that natural selection was the efficient agent in the formation of new Prof. Stanley Gardiner from the standpoint of zoology, and Prof. Johannsen on the botanical side, both emphasised the inadequacy of natural selection, whilst if we turn to Dr. Willis's Age and Area--a book which really gave rise to the discussion--we find the statement (p. 215): It is clear that it is no longer safe to consider that advantage to the species has had anything to do with the actual evolution of that species. Most serious of all, if we refer to Dr. Bateson's address to the American Association for the Advancement of Science on the occasion of their Toronto meeting in 1921 (2), we find the statement: That particular and essential bit of the theory of evolution which is concerned with the origin and nature of species remains is concerned with the origin and nature of species remains utterly mysterious. We no longer feel as we used to do that the process of variation, now contemporaneously occurring, is the beginning of a work which needs merely the element of time for its completion. is within the recollection of all that Bateson's address was made the pretext for a widespread and virulent attack on Darwinian teaching, an attack which was largely taken up throughout the United States and Canada, and very nearly led to the passing of a law prohibiting the teaching of evolution in the state of Kansas. If we now endeavour to form a judgment as to how far this very general dissatisfaction with the Darwinian theory is justified, the first step must be to turn to the authoritative presentation of that theory contained in the sixth and last edition of the Origin of Species. is boldly outlined in the first five chapters, the remainder of the book being occupied with answers to innumerable objections. In the first chapter the great variability of our domestic animals and cultivated plants is described; in the second Darwin deals with the of wild He points out that systematists who believed in the origin of each species as a distinct act of creation, nevertheless recognised subspecies and varieties which they regarded as described by descent from the main species; and that no line could be drawn between subspecies and species, because what some naturalists regarded subspecies others regarded as true He admits that the word variation is of vague and uncertain import. may mean a monstrosity, i.e. a considerable deviation from normal structure, or it may indicate the slight differences which distinguish the offspring of the same parent from one another. He expresses a doubt as to whether monstrosities such as frequently occur in domestic productions are ever permanently propagated in a state of nature. The second type of variation, on the contrary, he regards as of the highest importance: he states that such variations lead, by insensible steps, to the differences separating slight varieties and through these to the differences between well-marked varieties, and so to the differences separating subspecies and …