feedback is for  making  the  process  a 
 whole  lot  more  messy, to introduce  a 
 fractal  in the  spice mix...  things or 
 populations  of things start to  be self 
        referential or self eating        
 (autovore...) or spiraling in  or out... 
 in the sixties they did  research in the 
 jungle and in  the sea  and  they  found 
 that  feedback does not give rise  to an 
 equilibrium. they were  trying  to prove 
 that nature is a  tame beast.  but she's 
 this  may hold  true  out  there...  but 
 maybe not in signal  wizardry? depending 
 on  your  technique,  you  might  easily 
             find recurrences.