6 MAN THE ANIMAL 



hands given to him because he was the wisest creature j thus 

 substituting a bit of teleological natural theology for a perfectly 

 good, if unproven, biological working hypothesis capable of 

 being tested. In this matter Galen trailed along with Aristotle, 

 as was his wont. 



Whatever may turn out to be the ultimate views on this 

 somewhat recondite philosophical point, there can be no doubt 

 that the development of the hand enormously aided man in his 

 struggle for survival and progress. A remote, but extremely im- 

 portant, consequence usually overlooked is that the possession 

 of developed hands, as we know them with all their manifold 

 capabilities, opened out to man a much greater range of new 

 and enormously useful methods and techniques of getting a 

 living than those available to other animals. This is a matter 

 about which more will be said later. 



Physiologically the habitually upright posture is not yet an 

 unmixed blessing. It is so relatively recent an acquisition in 

 the evolutionary time scale that all of the necessary structural 

 and functional adaptations of the basic mammalian type of body 

 have not yet been completed. An obvious example of this is the 

 frequency of visceroptosis ("sagging innards" in a homely way 

 of speaking) and the distressing complications that often follow 

 in its train. Furthermore the upright posture increases greatly 

 the demands made upon the circulatory system, as compared 

 with the situation under the quadrupedal mode of life. Stout 

 as the circulatory system is there is evidence that the adoption 

 of the upright posture was followed by an associated increase 

 in the proportion of the total mortality assignable to that organ 

 system. But there would seem to be no doubt that the large credit 

 balance in the general biological bank accruing from the freeing 

 of the fore-limbs from locomotory duties, and thus making pos- 

 sible the development of highly specialized hands, a great deal 

 more than offset the general physiological and pathological 

 debits. 



The greater size and complexity of the human brain in com- 

 parison with that of any other animal has attracted the atten- 



