Natural Selection 



horse to the drinking fountain, but you cannot 

 make him drink." You may be able to bring a 

 child into the world, but you cannot secure its 

 survival. Variation brings into being mutants, 

 which are incipient species, but variation cannot 

 determine their survival. It is at this stage that 

 natural selection steps in. 



But because natural selection allows certain 

 mutations to persist, it is not correct to say that 

 natural selection has caused these mutations or 

 made or originated the species to which they give 

 rise. 



The Civil Service Commissioners do not make 

 Indian civil servants : they merely determine 

 which of a number of ready-made men shall 

 become civil servants. Similarly, natural selec- 

 tion does not make new species, it simply decides 

 which of a number of ready-made organisms shall 

 survive and establish themselves as new species. 

 Nor does natural selection always do as much as 

 this ; for it is not the only determinant of survival. 

 Its position is sometimes comparable to that of 

 the Medical Board which inspects and rejects 

 the physically unfit of the candidates which have 

 already been selected by some other authority. 



The examination conducted by natural selec- 

 tion may be compared to a competitive one. A 

 separate, independent examination is held for 

 each particular locality ; consequently the severity 

 of the competition will vary with the locality. 

 2B 385 



