Journal on Policy and Complex Systems
selection . ... During this shaking process , some balls will actually roll up the side of a pit and over a ridge , at which point gravity once again causes the balls to roll to the bottom of a new pit . ( p . 25 )
In Templeton ’ s landscape , both of the forces that make up evolution ( variation and selection ) are represented by actual forces . Still , gravity is the dominant force of the two , because in the only world we know , gravity eventually wins every argument . Thus , the model implies that every population must inevitably reach optimality , and that is not what we see in the fossil record .
Merrell ( 1994 ) shared my concern about Templeton ’ s inversion :
Templeton ( 1982 ), for example , suggested that Wright ’ s adaptive landscape should be turned upside-down . ... The trouble with this analogy is that it suggests that adaptive evolution is inevitable , as easy as rolling downhill , and it is difficult to avoid thinking of an adaptive pit as an evolutionary sinkhole rather than as an evolutionary pinnacle of successful adaptation . ( p . 134 )
If we had kept Templeton ’ s shaking force , and kept it nice and strong ( maybe with a magical demon doing the shaking ), his metaphor might have overcome its inevitability bias . However , his shaking force seems to have either weakened to a gentle jostling or disappeared entirely . As a result , a second story , which I have come to call the easy roller story , has grown up . In this easy-listening version of evolution , selection appears not only more powerful than other evolutionary forces but more certain as well . Instead of a population balanced precariously on a peak and facing a multitude of possibilities , a ball near a well faces a collapse of possibilities to one still small point . The inversion may have led to an erosion of popular understanding about how evolution works , leading to statements such as this one ( Fogel , 2008 ):
[ Some ] have suggested that it is more appropriate to view the adaptive landscape from an inverted position . ... Such a viewpoint is intuitively appealing . Searching for peaks depicts evolution as a slowly advancing , tedious , and uncertain process . ( p . 5 )
Evolution is a slowly advancing , tedious , and uncertain process . That is the whole point of the word “ struggle .” Evolutionary adaptation is not a carefree stroll along a sunlit path ; it is more like a dash through a mine field .
The Principia Cybernetica Web entry on fitness landscapes explains the flip in this way ( Heylighen , 1999 ):
It is unfortunate that the convention in physics sees systems as striving to minimize a potential function , whereas the convention in biology sees systems as striving to maximize a fitness function . Although this tends to be confusing , the two types
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