218 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1940 



matters. With due deference to the nature of the climatic variations 

 and geologic changes which are certain to occur in the next few thou- 

 sand years, there is nothing to be expected from such sources that 

 would seriously deter the human species from maintaining a com- 

 fortable existence on the surface of the earth for an indefinitely long 

 period of time — a period to be measured in millions rather than in 

 mere thousands of years. 



II 



At last, it is generally understood that man is a part of nature. 

 He may be something more than an animal (that depends largely 

 upon definition), but he is none the less truly a part of the animal 

 world. Like the other inhabitants of the earth, man is a product of 

 evolutionary processes operating on this particular planet. 



We may be the latest product of the creative forces displaying 

 themselves in the organic development taking place in this particular 

 portion of the cosmos, but we have no reason to assume that we are 

 the last achievement of those forces. Nor does the fact that man has 

 arisen from a lowly origin through processes of evolution validate the 

 optimistic inference that he will necessarily continue his progress to 

 ever higher levels of activity. Evolution does not guarantee prog- 

 ress ; it merely guarantees change. The change may be for the better 

 or the worse, depending upon the conditions of time and place and 

 the vitality of the individuals concerned. 



The pages of Mother Earth's diary reveal an amazing and thought- 

 provoking record of the progress of living creatures throughout the 

 long eras of earth history. Again and again, in the procession of the 

 living, dynasties of animals or plants have arisen from a humble 

 origin to a position of world supremacy, maintained for a compar- 

 atively brief period and then lost forever. Some have disappeared 

 entirely as their paths have led them off into blind alleys. Others 

 have sunk to a low level and have continued a degenerate existence 

 to the present day. A few have given rise to other and more efficient 

 forms of life that superseded their predecessors as leaders in the 

 procession. Gradually we are discovering some of the reasons for 

 success and failure along the path of life. Beyond question, man 

 may profit from these experiences of the past, if he uses the intel- 

 lectual and moral resources which are available for him. 



From the point of view attained through knowledge of geologic 

 life development, man has today a unique opportunity to gain con- 

 tinuing security for himself and his progeny on the face of the earth, 

 but whether or not he takes advantage of that opportunity is to be 

 determined largely by himself. So far as we can tell, man is the 

 first animal possessing the power to determine his own evolutionary 



