HUMAN ORGANIC EVOLUTION: FACT OR FANCY? 



Most striking among these latter are the small brain case with 

 a relatively large jaw, which give it an appearance not unlike 

 a chimpanzee or gorilla. But this has to be interpreted not as 

 a development in a simian direction but a phase in the general 

 direction of hominid development. The cranial capacity has 

 been estimated to be in the neighborhood of about 600 cc, 

 with an estimated range of 450 to 700 cc. which would exceed 

 the largest gorilla on record who is larger in body size than 

 Australopithecus and whose capacity is 685 cc. What is more 

 important than size is the fact that endocranial casts show 

 greater affinity with the hominidae than the pongidae in the 

 presence of the sylvian notch between frontal and temporal 

 lobe, and also the richness and complexity of the convolutional 

 impressions. Also more hominid is the rounded forehead, and 

 greater cranial height. Similarly the muscle attachment on 

 the occiput is low as in hominid forms. In general, with the 

 exception of the face, the skull bones are well developed in 

 the direction of hominoid forms. Furthermore, the shape of 

 the dentition, and the shape of the palate and even the teeth 

 are more like those of a human than those of an ape. In 

 regard to the limb skeleton, there is undoubted evidence that 

 Australopithecus had erect posture. This is significant, for the 

 skull seems to suggest by its retention of many simian features 

 an uneven or asymmetrical development.^ The most important 

 remains that document erect posture are the pelvic bones which 

 correspond in all important features to those of modern man, 

 except, perhaps, that they are slightly smaller. The erect 

 posture, so clearly represented by the pelvic bones, is further 

 corroborated by the lower limb skeletal remains which resemble 

 the hominoid femur, and reflect a mechanical adaptation to 

 completely erect bipedalism. 



The position of Australopithecus then in regard to earlier 

 fossil remains, and to later ones to be discussed below, may 

 be said to be on the hominid branch that eventually leads to 



^ This is very possible when functional aspects are considered, especially 

 the possibility that Australopithecus may not yet have been in the 

 possession of fire (cf. S. L. Washburn, "The New Physical Anthro- 

 pology," Transactions o[ the New York Academy of Sciences, II : 

 13 : 7, pp. 298 — 304). Also the problem whether Australopithecus was 

 a hunter is still being debated (cf. the exchange in American Anthro' 

 pologist, volumes 59 (1957) and 60 (1958). 



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