338 The Organization of Matter and Life 



operates independently, but all sets influence each other to some 

 degree. The total product is therefore extremely complex. 



The origin of life in the first place was the result of a series of 

 such processes extending back to the origin of the elements. Viewed 

 in this light both prebiological and biological evolution merge into 

 a single connected series of processes and events. 



Whichever theory of the origin of the present universe is correct, 

 most investigators seem agreed that the first step in the evolution 

 of the present universe was the formation of hydrogen from lesser 

 units of matter. The randomly distributed atoms of hydrogen which 

 resulted apparently had some sort of mutual attraction and ulti- 

 mately formed great galactic gas clouds. Various natural forces, 

 such as momentum, the laws of turbulence, and the force of gravita- 

 tion, brought about an increased orderliness within this galactic 

 cloud, resulting in the formation of high density gas balls which 

 evolved into the stars of the galaxy. 



After the evolution of stars, a curious mixture of randomizing 

 and ordering occurred. The gravitational properties of the star and 

 the nuclear properties of hydrogen lead to a tremendously hot struc- 

 ture which gives off energy as heat and light (randomizing) but 

 converts the hydrogen into elements of higher atomic weight (or- 

 dering). Stars have a curious evolution, leading finally to a random 

 scattering of most or all of their products into the residual galactic 

 gas and dust cloud. These materials again come under ordering 

 influences resulting in the formation of new stars composed chiefly 

 of hydrogen but containing some of the heavier elements. The 

 added elements in the star cause it to follow a difterent pattern 

 of nuclear evolution, and in this evolution new and heavier ele- 

 ments are formed. Thus the product of one evolutionary process 

 automatically changes the specific course and the specific prod- 

 ucts of the next cycle in the same process. In this scale our sun 

 is a third generation star. 



The origin of the planets of the solar system is still a matter of 

 conjecture. Their high percentage of heavier elements is highly 

 unusual in celestial bodies and suggests that the planets arose 

 from remnants of a twin star of the sun. When they are under- 

 stood, the processes leading to the formation of the planets will 

 undoubtedly prove to have been predicated by preceding events 

 and the action of logical processes of randomization and ordering. 



The chemical and physical properties of the earth's crust, oceans, 

 and atmosphere set the stage for a chemical evolution leading 

 to the formation of life. This evolution was an increase in chemi- 



