D.— ZOOLOGY 99 



Man is not destined to break up into separate radiating lines. For the 

 first time in evolution, a new major step in biological progress will produce 

 'but a single species. We can also set obvious limits to the extension of 

 his range. Thus the main part of any large change in the biologically 

 near future must be sought in the improvement of the brain. 



First let us remind ourselves that with our human type of society we 

 must give up any hope of developing such altruistic instincts as the social 

 insects. It would be more correct to say that this is impossible so long 

 as our species continues in its present reproductive habits. If we were to 

 adopt some system for using the gametes of a few highly endowed indi- 

 viduals, directly or from tissue-cultures, to produce all the next generation, 

 then all kinds of new possibilities would emerge. Man might develop 

 castes, and some at least of them might be endowed with altruistic and 

 communal impulses. 



Meanwhile there are many obvious ways in which the brain's level of 

 performance could be raised. If for all the main attributes of mind the 

 average of a population could be raised to the level now attained by the 

 best endowed ten-thousandth or even thousandth, that alone would be 

 of far-reaching evolutionary significance. Nor is there any reason to 

 suppose that such quantitative increase could not be pushed beyond 

 its present upper limits. 



Further, there are other faculties, the bare existence of which is as yet 

 scarcely established : and these too might be developed until they were 

 as commonly distributed as, say, musical or mathematical gifts are to-day. 

 I refer to telepathy and other extra-sensory activities of mind, which the 

 work of Rhine, Salter and others is now forcing into scientific recognition. 



In any case, one important point should be borne in mind. After 

 most of the major progressive steps taken by life in the past, the pro- 

 gressive stock has found itself handicapped by characteristics developed 

 in earlier phases, and has been forced to modify or abandon these to realise 

 the full possibilities of the new phase. This evolutionary fact is perhaps 

 most obvious in relation to the vertebrates' emergence from water on to 

 land ; but it applies in other cases too. 



Man's step to conscious thought is perhaps more radical in this respect 

 than any other. By means of this new gift, man has discovered how to 

 grow food instead of hunting it, and to substitute extraneous sources of 

 power for that derived from his own muscles. And for the satisfaction 

 of a few instincts he has been able to substitute new and more complex 

 satisfactions, in the realm of morality, pure intellect, aesthetics, and 

 creative activity. 



The problem immediately poses itself whether man's muscular power 

 and urges to hunting prowess may not often be a handicap to his new 

 mode of control over environment, and whether some of his inherited 

 impulses and his simpler irrational satisfactions may not stand in the way 

 of higher values and fuller enjoyment. The poet spoke of letting ape 

 and tiger die. To this pair the cynic later added the donkey, as more 

 pervasive and in the long run more dangerous. The evolutionary bio- 

 logist is tempted to ask whether the aim should not be to let the mammal 

 die within us, so as the more effectually to permit the man to live. 



Man seems generally anxious to discover some extraneous purpose to 

 which humanity may conform. Some find such a purpose in evolution. 



