390 EVOLUTION, GENETICS, AND EUGENICS 



15. There is a growing skepticism on the part of biologists as to 

 the extreme fierceness of the struggle for existence and of the conse- 

 quent rigor of selection. It may be answered that no very obvious 

 fierceness is implied in the theory. So long as overproduction and a 

 shortage of space and food exists the struggle for existence is inevitable. 



16. Special objections are offered to the subsidiary theory of 

 sexual selection. It is said that the type of sexual selection involving 

 active rivalry and battling for mates needs no special theory, inasmuch 

 as this is a mere phase of the struggle for the maintenance of the full 

 life, including the chance to leave offspring. It is against the other 

 side of sexual selection, which involves passivity on the part of the 

 male and active choice on the part of the female of the more beautiful 

 or otherwise attractive male, that objection is raised. It is claimed 

 that such choice implies too high aesthetic powers in animals of 

 relatively poor vision and mentality. Experiments have been per- 

 formed with moths, in which the male and female coloration is 

 strikingly different, in order to determine whether females actually 

 do exercise any choice of mates that is based on considerations of 

 appearance. The result proved conclusively that color patterns have 

 no value in mating, but that the female is passive and mates with the 

 first male to present himself, while the male finds the female through 

 his exquisitely effective sense of smell. 



We know now, however, that secondary sexual characters are 

 intimately bound up in a physiological way with the functioning of 

 the sex glands and are therefore doubtless to be interpreted as mere 

 non-adaptive correlative variations or else as examples of obliterative 

 coloration. 



DEFENSE OF SELECTION 



In presenting these sixteen objections, we have in most cases 

 indicated the lines upon which the objections have been met, if they 

 have been met. Not all of these objections are considered serious at 

 the present time, for some are based upon lack of a full knowledge of 

 what Darwin actually wrote; others are largely academic in character 

 and fail to stand up under actual test; still others have been more or 

 less adequately met by subsidiary or supporting theories which have 

 been advanced by various neo-Darwinians. 



Most of the special objections raised in this chapter have received 

 the attention of various able Darwinians, and the student of evolutiou 

 would doubtless be interested in the expert and fair-minded defense 



