Epilogue: What Conies of Studying Vertebrates 803 



hedgehogs. The other exceptional Order is Primates. The search for 

 specialized features whereby the Order may be defined yields only such 

 apparently trivial things as nails instead of claws or hoofs on the 

 digits, and the opposable pollex and hallux — and they are not oppos- 

 able in all primates. The primates have no anatomic characteristic 

 which, in its high degree of specialization and in its prominence as a 

 distinctive feature of the animal, is equivalent to the one-toed foot of a 

 horse, the dentition of a rabbit or sheep, the wings of a bat, the trunk 

 of an elephant, or the flippers and tail-flukes of a whale. This lack of 

 conspicuously distinctive anatomic peculiarities characterizes not only 

 the lemuroid primates but also the anthropoids, even the "great apes" 

 and man. 



Measured by the standards applied to members of other Orders of 

 mammals, the anatomic differences between a man and a chimpanzee 

 are trivial. They are less than the differences between the "great apes" 

 and the South American monkeys. That there is something quite 

 distinctive about the external aspect of the human body is not because 

 it has some very prominent peculiarities. It is the collective result of 

 many features, no one of which is of great anatomic magnitude. Form 

 of trunk, shape of head, absence of external tail, proportions of arms 

 and legs, upright posture associated with bipedal locomotion, re- 

 stricted distribution of hair, facial features, form of auditory pinnae — 

 in none of these particulars is there any extreme specialization peculiar 

 to the human body. But, from the perhaps prejudiced human point of 

 view, there seems to be a certain consistency and harmony among these 

 numerous particulars, and the whole assemblage of them imparts to 

 the body an appearance so characteristic that even a person without 

 biologic training readily distinguishes between a man and a chim- 

 panzee, although he may not be able to distinguish between a sala- 

 mander and a lizard — members of different Classes of vertebrates. 



man's relations to his environment 



Man is now the world's dominant animal. In this fact we are con- 

 fronted by an anomaly. Throughout the history of vertebrates prior 

 to the Age of Man, dominant positions have been attained only by the 

 more highly specialized animals of a given period. Of existing mam- 

 mals, the unspecialized insectivores survive by retreat. But the human 

 primate, conspicuously lacking in highly specialized anatomic character- 

 istics, is dominant. How has this dominance been achieved? 



The brain of the more primitive or lemuroid primate differs in no 

 important way from those of insectivores, rodents, and marsupials. 

 The anthropoid brain closely resembles that of carnivores and ungu- 

 lates. Its relative size, however, is somewhat greater and there is a 



