SCIENCE-GOSSIP. 



199 



THE PRESENT EVOLUTION OF MAN. 



By G. W. Bulman, M.A., B.Sc. 



A MONG evolutionists generally there seems to 

 be a wide-spread feeling of regret that, as 

 regards the human race, natural selection has 

 ceased its beneficent work. The artificial conditions 

 under which we live, and the preservation of the 

 unfit, have swamped its efforts for the improvement 

 of man. Thus, Dr. Wallace tells us that in one of 

 his latest conversations with Mr. Darwin, the latter 

 expressed himself very gloomily on the future of 

 humanity, on the ground that natural selection had 

 no place in modern civilization, and that the 

 fittest did not survive. Mr. Reid, however, points 

 out the welcome fact that we are still evolving 

 in certain definite directions : we are acquiring 

 immunity against diseases. The idea has much 

 to recommend it. Immunity against disease is 

 an unquestionable advantage in the struggle for 

 life ; and doubtless differences in susceptibility to 

 infection occur in different individuals. This is all 

 the theory of natural selection requires for the 

 evolution of a disease-proof race. The degree of 

 protection should go on increasing to absolute 

 immunity. For to however great a degree it had 

 gone, further immunity would always be an 

 advantage, and there would always be variation 

 in the direction of increased immunity. Such is 

 the pleasant prospect set before us as we open the 

 pages of Mr. Reid's " Present Evolution of Man." 

 Yet on reading further we find that the author 

 himself does not take quite such a rosy view. 

 His belief in the powers of natural selection are 

 not robust enough to allow him to prophesy an 

 absolutely disease-proof race. Immunity will only, 

 he thinks, reach a partial perfection. 



It is difficult to understand why natural selection 

 should thus stop short of absolute perfection. 

 Darwin himself had greater faith in its powers ; 

 for when a scheme for evolving a disease-proof 

 potato was proposed, he wrote : " Mr. Torbitt's 

 plan of overcoming the potato-disease seems to 

 me by far the best which has ever been suggested. 

 It consists in rearing a vast number of seedlings 

 from cross-fertilized parents, exposing them to 

 infection, ruthlessly destroying all that suffer, 

 saving those which resist best, and repeating the 

 process in successive seminal generations." If 

 natural selection were indeed the potent force it 

 must have been to do the work required of it by 

 evolutionists, it would, doubtless, ere this have 

 produced both a disease-proof man and a disease- 

 proof potato. 



The special subject which gives the title to 

 Mr. Reid's book is not met with, however, till we 

 reach the second part. In the first part we have 



a sketch of evolution in general — -practically a 

 defence of Weismann against Mr. H. Spencer and 

 others. It may seem to some superfluous thus to 

 go over the elementary principles of evolution in 

 a work of this kind. Yet, in these days of much 

 divergence of opinion on the theory, it becomes 

 necessary for each writer to state to which school 

 he belongs, or, to be more accurate, to explain the 

 principles of his own school. So, then, Mr. Reid 

 defines his own position as to the great theory of 

 natural selection. The general impression left by 

 a perusal of his pages is that his arguments are 

 more convincing when directed against the trans- 

 mission of acquired characters than in showing 

 how evolution can take place without it. Indeed, 

 the position seems to be this, that since acquired 

 characters are not transmitted, and since evolution 

 has taken place, it must be possible without such 

 transmission. An outline of the process of evolu- 

 tion is given. Like others, Mr. Reid seems to 

 think that, given the known abundance of variation, 

 and the admitted intensity of the struggle for 

 existence, evolution of species must follow as a 

 necessary consequence. The possibility that 

 variation and the struggle for existence, be they 

 ever so widespread and intense, might not be of 

 the kind required is ignored. Yet, given variation 

 which is strictly limited in amount, and a struggle 

 for existence that is largely indiscriminate, evolu- 

 tion of species does not follow as a necessary 

 consequence. The weak point, however, in the 

 present position of the theory is that these two 

 essential factors, variation and the struggle for 

 existence, have not been shown to be of the 

 nature required. Mr. Reid gives no assistance 

 on this point. 



As a matter of fact both these factors may have 

 been such as to render evolution by natural selection 

 impossible. Variation to meet the demands of 

 the view must be, or at least have been, in practi- 

 cally every direction ; for it must have covered the 

 difference between the first simple form of life and 

 every species of the higher forms which have ever 

 existed. It must also be unlimited in amount. 

 Now it has never been shown that variation is of 

 this nature, and there are several considerations 

 tending to show that it is not. Taking all the facts 

 into consideration, the balance of evidence seems to 

 indicate that variation is not of the nature required. 

 Again, it is conceivable that the struggle for 

 existence might be even severer than has been 

 demonstrated, and yet not tend to preserve slight 

 individual differences, for it might be largely or 

 altogether indiscriminate. Here, again, facts tend 



