MAN 183 



teeth have a distinctly hominid character, but the claim 

 that Oreopitheciis affords a link in the direct ancestry of 

 the Hominidae is not as yet supported by other ana- 

 tomical data and is contrary to the evidence that the 

 hominid stock was not evolved until some milHons of 

 years later. 



It is not possible to determine the level of intelligence 

 attained by these extinct forms except as we write a 

 rough equation between intelligence and brain weight 

 per unit of body weight. This equation is of little use, 

 if for no other reason than because the brain's potentiali- 

 ties, in the chimpanzee or in man, invariably exceed its 

 actual attainments. The chimpanzee, with its remarkable 

 capacity for learning and solving problems, is handi- 

 capped by the absence of articulate speech, by which 

 sounds can be converted into symbols and rearranged to 

 give new meanings, and without speech it is impossible 

 to judge how bright, by human standards, a chimpanzee 

 is. On the other hand, untutored man remains an in- 

 tellectual savage— it is the cultural treasure imparted by 

 education that converts him into a creator of science, 

 literature, music, philosophy, and art. The anthropolo- 

 gist infers that the mental capacity of fossil man in- 

 creased generally in the phylectic sequence from Aus- 

 tralopithecus to Homo sapiens, and that the first was 

 probably very near the beginning of speech. Probably 

 also in Australopithecus, ratiocination, the debating of 

 causes and effects, had begun to play a more important 

 role than instinct. 



Many of the important features in the transition from 

 ape to man represent what the biologist calls paedogene- 

 sis (pais, paidos = child; gignesthai = to be bom) , a phe- 

 nomenon frequently observed in evolution and repre- 

 senting the progressive arrest of development of a new 

 species in the juvenile or fetal state of the ancestral form. 

 Although at birth the human infant is by far the largest 

 newborn among the primates, it is, nevertheless, the 



