HUMAN ORGANIC EVOLUTION: FACT OR FANCY? 



closely the hominidae (man's ancestral family) than the 

 pongidae (ancestral to apes) in such characteristics as the 

 construction of the molars, and other dental traits. These 

 fossils suggest a transitional stage away from the pongidoid 

 stem. But other fossil evidence from India is too scanty to 

 warrant further speculation about a branching off in a hominid 

 direction. From Europe came a femur and shaft of a humerus 

 of Dryopithecus and parts of a limb skeleton of Pliopithecus. 

 These, and similar and more complete finds from East Africa 

 {Proconsul and Limnopithecus) , suggest that they had not 

 yet developed towards the extreme features of the modem 

 apes by virtue of being more slender and straight than would 

 be expected of an ape-like trend. Some very recent Pliopithecus 

 finds from Middle Pliocene times in Austria suggest even 

 certain cercopithecoid affinities. In general these fossils show 

 more affinities with the quadruped cercopithecoid monkeys of 

 today than with the brachiating apes according to Clark. ^ 

 These finds suggest a divergence of pongidae and hominidae 

 which may be placed at early or middle Miocene times. 



The importance of these finds is enhanced by considering 

 some functional aspects. It stands to reason that perhaps at 

 this time, at least some of the common ancestors of man began 

 to stay fairly close to the ground, as is evidenced by the very 

 large East African ape {Proconsul major whose size is equi- 

 valent to modern gorilla) which at the most could only 

 braciate in lower and sturdy branches of trees and probably 

 was also moving about on the ground a great deal. But the 

 limb bones for this fossil have not been found, which, when 

 found, will shed further light on this problem. An important 

 consideration is the environment of East Africa at that time, 

 which consisted of only slightly wooded valleys (as evidenced 

 by the faunal assemblages in Kenya) separated by savannas 

 which could have provided the stimulus for development 

 towards ground living forms. As Clark^ points out, the attempt 

 was not to abandon arboreal life, but to retain it, that is those 

 who tried to go from one shrinking woodland to another could 

 do so only if they were able to move effectively on ground. 



Whether this group of fossils is ancestral to man and to 



5 Op. cit, p. 169. 



6 Op. cit., p. 170. 



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