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.