CHAPTER II 

 " ARBOREAL MAN " 



The little more and how much it is. 



IF any reader is still unconvinced of the fundamental and 

 universal importance of food as a determining factor in the 

 achievement of evolutionary success, I would advise him to turn 

 to Prof. Wood Jones's book on Arboreal Man, in connection 

 with the present volume. 



The author does not take by any means so strong a view as 

 I do of this importance, and this renders his testimony all the 

 more valuable when its relation to my views is seen. 



As regards the author's main thesis, a publisher's note gives 

 us the following information : 



Put as concisely as possible, although the argument of the book does 

 not readily admit of being summarised briefly, Dr. Wood Jones's theme 

 is a demonstration of the fact that Man, the supreme product of Evolution, 

 could only have been developed from animals which had their homes and 

 spent much of their lives in trees ; the main point in the argument being 

 that the descendants of primitive animals living on the ground were 

 inevitably doomed to become quadrupeds, and so missed the chance of acquir- 

 ing the upright posture which is one of Man's distinctive attributes, at 

 the same time paying for more immediate advantages by losing for ever 

 that invaluable organ, the hand. Stated in these crude terms, the matter 

 might at first sight seem to be only a chapter, though an important one, 

 in the story of Human Evolution ; but before the reader has progressed 

 very far, he will begin to realise that the arboreal habitat is not merely 

 one of the conditions, but the central and dominating factor in the whole 

 process. Not that living in trees was in itself sufficient to determine the 

 line of progress in an upward direction. Many classes of animals lived, 

 as many still live, mainly in trees. Mr. Wood Jones, reasoning on lines 

 which would delight the heart of M. Henri Bergson, shows how and why 

 only one of these classes continuously achieved " the successful minimum 

 of specialisation," and moved slowly but surely in a direction which ended 

 in Man, and not in a Lemur or a Sloth. 



We have already seen that mere expediency of adaptation 

 is not in the end conducive to progressive evolution, and that 

 the achievement of the " successful minimum of specialisation,"" 



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