368 The Outline of Science 



and the gardener effect is brought about by the struggle for 

 existence. 



Darwinism in Process of Evolution 



These three propositions express the gist of Darwinism, and 

 the question before us is, How Darwinism stands to-day. Before 

 trying to answer this difficult question, we may point out that it 

 would be a sorry business if Darwinism stood to-day as it was 

 left by Darwin. He knew well that he had only begun to 

 solve the problem of organic evolution; he looked forward with 

 clear eyes to changes that the progress of science would 

 enforce. It would be a terrible contradiction in terms if an 

 evolution theory did not itself evolve! The marvel is, not that 

 it is necessary to make some changes in what Alfred Russel 

 Wallace so generously called "Darwinism," but rather that so 

 much of Darwin's doctrine stands firm, four-square to the winds. 



Another preliminary note is unfortunately necessary, that 

 it is quite illegitimate to infer from our dubiety in regard to the 

 factors of evolution any hesitation as to the fact. Our frankness 

 in admitting difficulties and relative ignorance in regard to the 

 variations and selections that led from certain Dinosaurs to Birds 

 cannot be used by any fair-minded inquirer as an argument 

 against the idea of evolution. For how else could Birds have 

 arisen? As Wallace said in 1888, "Descent with modification 

 is now universally accepted as the order of nature in the organic 

 world." But the question before us is this: What, as regards 

 the factors in evolution, have been the changes since Darwin's 

 day? 



The Three Problems of Evolution 



There are three great problems before the evolutionist: 

 (1) What is the origin of the new? (2) What are the laws of 

 inheritance? (3) What are the sifting methods that operate on 



