26. LAW OF GEOLOGICAL ALTERNATIONS 

Since the short revolutionary periods exert a strong selective force upon the biota, highly differentiated life forms are more likely to develop during those times than during equable normal periods. 

 

Life forms are apt to alter less
Throughout long times of normalness.
Change is inclined to run apace
In revolution's brief embrace,
During which, life forms that emerge
Are more likely to diverge.