66 CONTROLLED NATURAL SELECTION 



sideration because they are self-evidently a 

 means whereby Natural Selection within a 

 family is controlled. 



Many account for the parental sacrificing 

 instinct by concluding that the young and 

 the juvenile, because they are helpless and 

 inexperienced in defence, require protection 

 of their parents. But such an argument is 

 not sound. They require protection because 

 they are valuable to the species : their help- 

 lessness adds nothing to their value. How- 

 ever, apart from this question : the origin 

 of these characters as variations confined to 

 particular members of a society and their 

 fixation, must have been through Natural 

 Selection dealing with families, and not with 

 individuals ; and further, these characters 

 must control Natural Selection in such a way 

 that one set of individuals, the young, is 

 rendered more liable to be selected for sur- 

 vival than the other, the parents. 



