260 Kansas Academy of Science. 



MUTATIONS AND THE EVOLUTION OF MAN. 



By Alton H. Thompson, Topeka. 



npHE discovery and demonstration of the principle of mutations 

 -^ in the formation of species and varieties of plants, by Hugo 

 De Vries, is one of the most brilliant achievements in the history 

 of evolution since the publication of Darwin's "Origin of Species." 

 Its recent promulgation has thrown a flood of light upon many 

 puzzling and obscure questions, and has aided materially in the 

 solution of some intricate problems in the science of biology. Of 

 course, there is danger of carrying it too far in its application, like 

 all revolutionary discoveries, for after all it only supplements nat- 

 ural selection and assists in solving problems that that great prin- 

 ciple could not account for. It is a source of wonder to later 

 scientists that Darwin, with all his observations and great insight 

 into the workings of nature, should have failed to perceive the idea 

 of sudden mutations, and held it as an inviolable principle that all 

 changes of structure were due to very gradual alterations, the re- 

 sult of natural selection. 



Darwin succinctly states his doctrine in a letter to Haeckel, as 

 follows: "Having reflected much on the facts, it seems to me 

 probable that allied species were descended from a common ances- 

 tor. But during several years I could not conceive how each form 

 could have been modified so as to become so admirably adapted to 

 its place in nature. I began, therefore, to study domesticated ani- 

 mals and plants, and after a time perceived that man's power of 

 selecting and breeding from certain individuals was the most pow- 

 erful of all means in the production of new races. Having attended 

 to the habits of animals and their relations to surrounding condi- 

 tions, I was able to realize the severe struggle for existence to which 

 all organisms are subjected; and my geological observations had 

 allowed me to appreciate the duration of past geological periods. 

 With my mind thus prepared, I fortunately happened upon Mal- 

 thus's 'Essay on Population,' and the idea of natural selection 

 through the struggle for existence at once occurred to me." 



So it remained for the astute mind of De Vries to perceive that 

 sudden changes of structure were possible, and under certain con- 

 ditions could be made permanent. The general acceptance and 

 the revolutionary effect of the idea of the origin of species by mu- 

 tations has been marvelous, and is second only to the revolutionary 



