left-right reversal of CNS: Why?

kenneth paul collins KPCollins at postoffice.worldnet.att.net
Mon Sep 9 16:12:56 EST 1996


>I don't understand how organisms with radial symmetry can have crossed 
>representation

they don't... what I said in my original post was that the overall 
phenomenon can be traced back to organisms having radial symmetry... 

...the highly-inefficient radial-symmetry "correlate" of decussation 
exists in the spread of activation through the radial net... one 
observes the net's response to stimuli... the outward appearance is 
somewhat like the gradual deformation of, say, an orange, the juice of 
which is being sucked out through a hole poked through the orange's 
skin... such is a topological inversion of the topology of the 
phenomenon of decussation... to communicate with "the orher side of the 
circle", radially-symmetric organisms just pass activation around the 
circumference... this leisurely rate of signalling allows only 
relatively slow whole-organism coordinated motion...

...it's in this sense that the phenomenon can be traced back to 
organisms having radial symmetry... the inefficiency of the 
radial-symmetry topology exposes the need for decussation... ken



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