Evolvability of Recurrent Nets

[JANSSEN Jacques]

Dear Connectionists,
                     Has anyone out there done any work on, or know
about people who have done work on evolvability criteria for time dependent
recurrent network behaviors? There's a growing literature now on using the
Genetic Algorithm to evolve dynamic behaviors in neural networks, but these
attempts sometimes fail. Why? To give a simple (static) example - take
the multiplier problem. The aim is to evolve a network which takes two
real numbered inputs and returns the product as its output. If the inputs
can be of mixed sign, the network does not evolve. If the inputs are always
positive, the network evolves. This is just the beginning. I have several
examples of desired dynamic behaviors which failed to evolve.
 
Kaufmann has talked about criteria for evolvability of his (simple) Boolean
networks. Has anyone seen work on extending these ideas to recurrent nets?
Or anything which might do the job?
 
Cheers, Hugo de Garis,
 
        Univ of Brussels, &
        George Mason Univ, VA.