GEOLOGICAL PERSPECTIVE HAWKINS 261 



one generation to another, may be everlasting; but all living things 

 are mortal. 



This sounds like a somewhat morbid summary of the course of an 

 ordinary human life ; but actually it is a description of the evolution 

 of every large or small group of organisms of which we have adequate 

 paleontological knowledge. 



There are two harmonies essential for successful living, one internal 

 and the other external; both must be kept consonant. The several 

 organs of an organism must maintain their proper proportions, and 

 the organism as a whole must conform to its surroundings. Internal 

 discord, due to the modulation of one ingredient independently of 

 the rest, cannot fail to produce inefficiency and final collapse; while 

 external discord brings the individual into mortal conflict with an 

 invincible opponent. One or the other of these disasters is in store 

 for every living thing, be it a cell, a body, a race, or a species. To 

 be alive is to be changing, and there is a limit to the range of possible 

 harmonies. 



Recognition of the orderliness of animate nature, and of the inevi- 

 table sequence of change, decay, and replacement, does not engender 

 optimism when we think of ourselves, our institutions, and our species. 

 A complicated mammalian mechanism with an overdeveloped nervous 

 system seems like a diagnosis of a very short-lived race. 



If we despairingly claim that our wits have enabled us to reduce the 

 risks of environment, the records of our history are open to show that 

 the internal dangers develop none the less. Diseases of dispropor- 

 tionate development, such as cancer, attack individuals ; and civiliza- 

 tions crumble through overcomplexity and dissension. Our clever- 

 ness may make our success spectacular, but it speeds on the ensuing 

 collapse. 



By virtue of our overdeveloped intelligence we accelerate the 

 processes of evolution, especially in our social relations ; and whatever 

 hope evolution may hold for the unborn, a tomb is all that it can offer 

 to the living. The history of the decline and fall of empires makes 

 familiar reading for a paleontologist ; it illustrates in a condensed and 

 diagrammatic form the late phases of evolution in other creatures 

 that are the normal subjects of his study. Regrettable though it may 

 be, the human animal seems to a paleontologist superior to a dinosaur 

 or an ammonite merely in the speed with which it rushes toward 

 extinction. 



This is a tragic outlook; but there is nothing unfamiliar about it. 

 All individuals realize, when they choose to think, that they are not 

 immortal; every philosophy and religion lays emphasis on the tran- 

 sient nature of "man's earthly hopes." It is not only the paleontol- 

 ogist who knows that the prize awaiting the winners in the struggle 

 for existence is death. Nor need we be morbid in our outlook ; a man 



