lyS evolution: the ages and tomorrow 



division of one directly into two, gives it a sort of relative 

 immortality. A piece of the original ancestor is still being 

 handed on; whereas in man, although the germinal plasma is 

 carried forward, the body tissue that is the living, sentient 

 being dies after a brief existence. 



Why, then, did nature organize at an early period, and 

 doggedly follow through for all of geological time, a pro- 

 gram of trying for larger and larger organisms of greater 

 and greater complexity? For animals the answer must be 

 that only through the organization of a nervous system, 

 consisting of almost countless neurons that are nourished 

 and maintained by efficient organ systems, could high-level 

 mind find expression. Obviously, nothing comparable to the 

 mind of man with its endless potentials of neuron association 

 and integration is possible in the limited volume offered by 

 the lower forms of life. From an anthropomorphic point of 

 view volume is so critical that nature often fails in her pur- 

 pose in a very discouraging manner. On innumerable occa- 

 sions some adaptive change occurs that limits the mind pos- 

 sibility. In insects (which are not without talent, as we have 

 seen) the adoption of air-breathing tubes and an outside 

 skeleton fixed size at such small proportions as forever to 

 hold in check the development of top-level intellect. In 

 birds the adoption of feathers and, through these modified 

 reptilian scales, the mastery of the air limited over-all size 

 and, especially the brain case. So critical is this limitation 

 that the bird is relegated to an inferior mental level. And 

 similar limitations occur for most of the species that make 

 up the animal kingdom. In plants it was the adoption of the 

 cellulose cell wall and food-getting by photosynthesis that 

 held them in check— held there, in fact, by nature's drive to 

 utilize to the fullest extent the chemistry of our world, to 

 capture and to hold the energy of sunlight for the use and 

 advancement of animal form. 



The primates and finally man were, and still are, in the 

 best position to progress mentally. At least in their highest 



