CHAPTER X 



Determinate Evolution by Natural and Organic 

 Selection ^ 



§ I. Criticisms of Neo-Darzvinism and Neo-Lamarckism 



Admitting the possible truth of either of the current 

 doctrines of heredity, called Neo-Darwinism and Neo- 

 Lamarckism respectively, yet there are certain defects 

 inherent in both of them. Natural selection, considered 

 merely as a principle of survival, is admitted by all. It 

 fails, however, (i) to account for the lines of progress 

 shown in evolution where the variations supposed to have 

 been selected were not of importance enough at first 

 to keep alive the creatures having them {i.e., were not 

 of real utility). The examination of series of fossil 

 remains, by the paleontologists, shows structures arising 

 with very small and insignificant beginnings.^ Further, 

 (2) in cases where correlations of structures and functions 

 are in question, as in the case of complex animal instincts, 

 it is difiicult to see what utility could be attached to the 

 partial correlations which would necessarily precede the 

 full rise of the instinct ; and yet it is impossible to believe 

 that these correlations could have arisen by the law of 

 variation all at once as complete functions.^ These two 



1 From The Psychological Review, July, 1897, PP- 393 ff* 



2 Cf. the statement of this objection by Osborn, American Naturalist, March, 

 1891. 



3 Cf. Romanes, DarwiJi and after Darwin, Vol. II., Chap. III. 



^2>S 



