98 



D. E. SAVAGE 



fauna are to a large degree, then, reflections of the paleodynamics 

 of the fauna. 



Our symposium theme. Origin and Affinity, involves certain rea- 

 soning and inferences, probably elementary to most zoogeographers, 



TAXONOMIC COMPARISON OF LIVING LAND-MAMMAL FAUNAS 



EAST 

 ASIA 



NORTH 

 AMERICA 



100% 



SOUTH 

 AMERICA 



ENDEMIC AUTOCHTHONS 





Fig. 



^1. A graphic demonstration of the approximate percentage of 

 living nonmarine mammalian taxonomic units of North America that are 

 also found in East Asia and in South America respectively. 



certainly basic to paleozoogeographers, that can appropriately be 

 acknowledged and reviewed; for they form a philosophic back- 

 ground to our interpretations. It is fitting that a paleontologist 

 make the initial review of this background for he is particularly 

 concerned with the secularly developed phases in the evolution 



