276 THE EVOLUTIONARY CAREER 



(or events, or physical changes) continually becomes unavailable 

 for such happenings, or the universe, as a whole, runs down. 

 These statements also apply to such limited parts of the universe 

 as a star, a cooling planet, chemical substances that have potential 

 energy and radio-active atoms. When we apply the entropy- 

 concept to organic evolution we have also to consider the energy- 

 exchanges between the system that evolves (say the acorn) and 

 the environment. We find that although (in the long run) the 

 conclusion of universal entropy-increase holds good there is, in 

 the evolving organic system a local entropy-decrease. This 

 means that in this local, living system energy that would other- 

 wise have become unavailable retains a certain fraction of its 

 availability. 



It is plain, therefore, that with respect to the entropy-law the 

 processes of inorganic and organic evolution exhibit contrasted, 

 or opposite tendencies. 



91. ON THE MEANING OF THE TERM 

 ''EVOLUTION '' 



We can best discuss what we mean by " evolution " by reference 

 to processes of individual organic development — since an organic 

 evolutionary process is simply a series of developments in a race 

 of organisms. There is differentiation in this series such that 

 the individual, developmental processes change and so a race 

 *' evolves." 



The term evolution obviously implies a previous " involution." 

 Something that was rolled-up, wrapped-up, " latent," etc., 

 becomes unrolled, unwrapped, " patent," etc. This was the 

 original conception and it was replaced by that of epigenesis, 

 which meant that something new% as regards bodily structure, came 

 into existence in the developmental process. As we have seen 

 (in Chapter VI) the epigenetic conception became accepted during 

 that period when materialistic-energetic views were generally 

 extended to all organic processes and the result was the revived 

 conception of preformation, as it was applied to developmental 

 processes by Weismann and, later on, in its present form, by 

 Morgan and his followers. What were *' involved " in an 

 individual development were the genes and these particles, or 

 agencies, or quanta, became '' deployed," interacted with each 

 other and with the environment so as to display an individual 



