Interestingly when these systems are run global properties do emerge. Such systems, in some way, self-organize to create structures that do not exist within the rules by which they operate. This is the same process that operates in organisms. Their form is not, as neo-Darwinism presumes, selected for by external forces, but it emerges due to the internal interactions between the constituent parts. This process operates at multiple levels, molecules self-organize from atoms, cells from molecules, organisms from cells, societies from organisms, ecosystems from societies, planets from ecosystems.
These systems are self-maintaining (or autopoietic), their emergent natures are relatively stable to perturbation, they persist in the face of adverse external selective forces. This idea that micro-interactions produce macro-structure without external intervention is crucial to complexity thinking, and is a step beyond our current technology. By using such an organic approach, we allow the possibility that, once we understand the processes involved, we can grow machines that can perform desired functions from scratch, without necessarily having the slightest knowledge as to how they actually work...