CHAPTER 18 



Amplifying Adaptation 



Selection in the state -determined system 



18/1. The origin of selections ceases to be a problem as soon as 

 it is realised that selection, far from being a rarity, is performed 

 to greater or less degree by every isolated state-determined 

 system (/. to C, S. 13/19). In such a system, as two lines of 

 behaviour may become one, but one line cannot become two, so 

 the number of states that it can be in can only decrease. 



This selection is well known, but in simple systems it shows only 

 in trivial form. The spring-driven clock, for instance, is selective 

 for the run-down state: start it at any state of partial winding 

 and it will make its way to the run-down state, where it will 

 remain. The often-made observation that machines run to an 

 equilibrium expresses the same property. 



In simple systems the property seems trivial, but as the system 

 becomes more complex so does this property become richer and 

 more interesting. The Homeostat, for instance, can be regarded 

 simply as a system, with magnets and uniselectors, that runs to 

 a partial equilibrium, where it sticks. But the equilibrium is only 

 partial, and therefore richer in content than that of the run-down 

 clock. The uniselectors are motionless but the magnets may still 

 move, and the partial equilibrium manifests a dynamic homeostasis 

 that has been selected by the uniselector's process of running to 

 equilibrium. Thus the Homeostat begins to show something of 

 the richness of properties that emerge when the system is complex 

 enough, or large enough, to show: (1) a high intensity of selection 

 by running to equilibrium, and also (2) that this selected set of 

 states, though only a small fraction of the whole, is still large 

 enough in itself to give room for a wide range of dynamic activities. 

 Thus, selection for complex equilibria, within which the observer can 

 trace the phenomenon of adaptation, must not be regarded as an 

 exceptional and remarkable event: it is the rule. The chief reason 

 why we have failed to see this fact in the past is that our terrestrial 



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