THEORIES AND MECHANISM OF EVOLUTION 



651 



important during this early period in stimu- 

 lating others to propose other theories from 

 which the correct one finally emerged. 



Although interested in natural history as 

 a child, Charles Darwin's (Fig, 26-1) col- 

 lege training was in medicine and theology. 

 Neither of these professions suited his 

 taste, so when the famous naturalist, Pro- 

 fessor Henslow, suggested that he might 

 accompany and assist him on the ship 

 Beagle for a five-year cruise around the 

 world, Darwin grasped the opportunity to 

 continue his earlier studies of geology and 

 biology. The British Navy needed maps 

 and charts of Great Britain's oceanic island 

 possessions, as well as some knowledge of 

 their geology and natural history. The trip 

 took him to the east and west coasts of 

 South America, to Ecuador and west to the 

 Galapagos Islands. It was while he was 

 making a comparison of the flora and fauna 

 of these islands, together with their geol- 

 ogy, with that of South America that he 

 became convinced that living things were 

 not static nor specially created as he had 

 thought up to this time, but rather that they 

 were undergoing constant change and that 

 this change was intricately linked with die 

 movements of the earth's surface. This ex- 

 tensive cruise gave him a rare opportunity 

 to study animals and plants in different 

 parts of the world where he could see those 

 relationships. It is interesting to note that 

 Darwin left England a devout special crea- 

 tionist and returned, after five years of 

 direct field study of natural history, with 

 very little reference to the works of others, 

 a confirmed evolutionist. 



During the trip he gathered voluminous 

 notes which, when assembled back in Eng- 

 land in the course of the next twenty years, 

 so thoroughly convinced the world of the 

 validity of evolution that it has never been 

 seriously questioned since. This one effort 

 alone placed Darwin head and shoulders 

 above his contemporaries or predecessors. 

 Not satisfied with this accomplishment, he 



Fig. 26-1. Charles Darwin in his later years. He was 

 born February 12, 1809, the same dote a famous 

 American was born, and died in the year 1882. 



sought an explanation for evolution which 

 eventually was resolved in his theory of 

 natural selection. This second achievement, 

 added to the first, projected Darwin to a 

 position in man's intellectual progress that 

 had never before been attained and may 

 never be again. 



A quirk of fate brought forth the charac- 

 ter of Darwin when his good friend, Alfred 

 Russell Wallace, working over the flora and 

 fauna of the Malay Peninsula and the East 

 Indies, hit upon an explanation of evolution 

 which was in essence identical with his 

 own natural selection. He conveyed his 

 ideas to Darwin in the form of a letter. This 

 occurred in the year 1858 after Darwin had 

 completed his data and was about to con- 

 sider publishing his findings. Rather than 

 rushing into print to obtain priority as a 

 lesser man might have done, Darwin 

 presented a short draft of his work 



