Subsystem and interconnection strategies for intrinsic evolution of analogue hardware

The possible achievements of any given system for intrinsic evolution of analogue hardware are limited by the a range of sub-systems provided as building blocks for the system and the range of interconnections between the sub-systems that is permitted by the switching circuitry. The authors discuss the advantages and disadvantages of different levels of subsystem and interconnection and propose that a compromise that involves moderately complicated sub-systems with mostly limited interconnections is the most practicable at present