EVOLUTION THE MASTER-KEY 



not dwell here; or, at any rate, we need not re- 

 count the main theses of the Descent of Man, for 

 that work, like its predecessor, may now be pur- 

 chased for a sum so small that no one who affects 

 an interest in the science of life can confess that he 

 does not possess a copy of it. 1 



My purpose, in this as in other instances, is to 

 show that recent study has confirmed the beliefs 

 of the evolutionists. Darwin himself, after much 

 consideration, said, " I still strongly think . . . that 

 sexual selection has been the main agent in forming 

 the races of man." The Darwinian idea is based 

 partly on the conception of struggle, partly on the 

 conception of taste. Males with certain advan- 

 tages, such as fleetness and strength, would tend to 

 leave more offspring than their rivals; while the 

 taste of the females would choose certain males 

 rather than others, and so would tend to perpetu- 

 ate and accentuate certain characters. The male 

 beard, for instance, is a "secondary sexual char- 

 acter" so produced. 



This idea of sexual selection has lately undergone 

 a most interesting development at the hands of 

 Professor Karl Pearson and his followers. Pro- 

 fessor Pearson distinguishes two kinds of sexual 

 selection. The first, which Darwin discussed, is 

 based on the conception of taste and may be called 



1 In England the Origin of Species (the somewhat imperfect 

 edition issued by the Rationalist Press Association) may be 

 had for fourpence halfpenny, and the Descent of Man for half 

 a crown. 



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