THE ANIMAL ANCESTRY OF MAN 87 



babies of various races might be reminiscent of a primitive 

 quadrupedal ground phase following the erect aboreal phase. 

 But on the whole the present evidence seems to favor the 

 view that when man's ancestors came down out of the trees 

 they held the body erect while walking, as does the gibbon. 



While there are hterally thousands of items of evidence 

 for the inference that man is a speciahzed pecuHar offshoot 

 of the anthropoid stock, the exact time of his separation 

 from that stock and the more precise description of its 

 anatomy are matters of inference as to which there is room 

 for differences of opinion. Tlie known fossil record of man's 

 nearest relatives, while very meagre, indicates that during 

 the Eocene, or first grand division of the Age of Mammals, 

 only the lower grades of the Primates were in existence. 

 By the time of the Lower OHgocene the short-jawed pred- 

 ecessors of the anthropoid group were estabhshed. In the 

 Miocene and Phocene epochs varied species of anthropoid 

 apes roamed over Europe and India, some of which fore- 

 shadowed man in the patterns of their molar teeth. Then 

 there is a blank in the record and by the time of the Upper 

 Pliocene and Lower Pleistocene several widely different 

 types of human skull were already in existence. There is 

 considerable indirect evidence that the rate of evolution in 

 the earlier races of mankind was far higher than it was in 

 other groups of animals and it is not unlikely that the 

 rapid emergence of man as a creature of the open plains 

 took place in the vast periods of time represented by the 

 Miocene and Pliocene epochs. 



We are not yet informed as to whether this emergence took 

 place in Asia, Europe or Africa. The claims of the high 

 plateau region of central Asia as a possible center of dis- 

 tribution of the nascent Hominidae have been urged by 

 Professor Osborn (1926), and several fossil teeth of unques- 

 tionably human type have been found imbedded in a cave 

 deposit in China that contained other fossil mammals of 

 apparently Pleistocene age. But the origin of man from the 

 anthropoid stem must be sought in a far older epoch, perhaps 

 the Miocene, so that there would be plenty of time, if man 

 originated elsewhere, for him to have reached eastern Asia 

 by Pleistocene times. Also it must be admitted that the three 



