I never took a formal GA course, so this question might be vague: I’m trying to see whether I’m approaching this problem well.
Usually a genome is represented as a sequence of homogeneous elements, such as binary numbers, logic gates, elementary functions, etc., which can then be assembled into a homogeneous structure like a syntax-tree for a computer program or a 3D object or whatever.
My problem involves evolving a graph of components, lets say X, Y and Z: the graph can have N nodes and each node is an instance of either X, Y or Z. Encoding such a graph structure in a genome is rather straightforward, however, I also need to attach additional information for what X, Y and Z do themselves–which is actually the main object of the GA.
So it seems like my genome should code for a heterogeneous entity: an entity which is composed both of a structure graph and a functionality specification. It is not impossible to subsume the elements (genes) which code for the structure and those that code for functionality under a single parent “gene”, and then simply separate them when the entity is being assembled, but this doesn’t feel like the right approach.
Is this a common problem in GA? Am I supposed to find a “lower-level” representation / genome encoding in this situation? What are the relevant considerations?