34 evolution: the ages and tomorrow 



that were evolved in the early seas more than a billion years 

 ago have been floated down to our time on a river of ger- 

 minal plasm, projecting in each succeeding age endless and 

 varied individuals, changed and changeless, new and old, 

 from the naked genes of life's origin to the fully clothed 

 fauna and flora of our day. 



It is well to be reminded again that however advanced 

 and intelligently active the life of our day now is, it began 

 more than 2,000,000,000 years ago in the newly forming 

 seas— imperceptibly, gradually and naturally, molecule by 

 molecule, following the laws and relationships that apply 

 throughout the universe. Hydrocarbons and ammonia, the 

 primary compounds in the evolution of the living, literally 

 rained out of the skies of those ancient days. With water 

 vapor the hydrocarbons formed alcohols and organic acids; 

 these, in turn, reacting with ammonia formed amines and 

 amides, which are the definite forerunners of that which 

 became the building block of life, the amino acids. Fats and 

 sugars were synthesized in those early seas long before any 

 truly living organism appeared. 



Organic colloids arose which had the peculiar property 

 of forming "water skins" around the particles and, hence, 

 came to the level of the first individualized entity— the co- 

 acervate. From coacervates which took on enzymatic char- 

 acteristics and later became self-reproducing there arose, in 

 all probability, the viruses and genes. Genes associated to 

 form the first chromosomes, and the chromosomes sur- 

 rounded themselves with protoplasm to form the first cells. 

 The real unit of life, the gene, became the center of organ- 

 ization of all that was to be passed on— centers around which 

 the mechanism of evolution operates. 



