154 



THEORY OF EVOLUTION 



Selection, tlien, has not produced anything 

 new, but only more of certain kinds of indi- 



A 2 A3 



Fig. T9. Curves showing how (hypothetically) selection might 

 be supposed to luring about progress in direction of selection. 

 (After Goldschniidt.) 



viduals. 



more new tilings 



Evolution, however, means producing 

 not more of what already 

 exists. 



Darwin seems to have thought that the range 

 of variation shown by the offspring of a given 

 individual about that type of individual would 

 be as wide as the range shown by the original 

 population (fig. 79), but Galton's work has 

 made it clear that this is not the case in a gen- 

 eral or mixed population. If the offspring of 

 individuals continued to show, as Darwin seems 

 to have thought, as wide a range on each side of 

 their parents' size, so to speak, as did the orig- 

 inal poj^ulation, then it would follow that se- 



I 



