| Abstract |
A developmental view of evolving systems (ecological, social, economical, organizational) is proposed to clarify 1: the role of selection processes versus collective, nonselective processes, 2: the origins of diversity and its role in system performance and robustness 3: the precursors of explicit subsystem interactions (cooperation / competition / symbiosis) that enhance system performance, 4: the preconditions necessary for further evolutionary development, and 5: the conditions for the return to a prior stage. Three sequential stages of evolving systems (based on the work of Salthe) are proposed: a Immature or Developing stage dominated by highly decentralized , selective processes with chaotic dynamics (local and global), a Mature or Developed stage dominated by nonselective, self-organizing processes with global robustness but locally chaotic dynamics, and a Senescent stage dominated by rigid interactions with global fragility. A simple model problem, an agent solution to a maze (a sequential problem with many optimal and non-optimal solutions) is constructed to illustrate the entire developmental history and to clarify the above issues. Within the model, the agents evolve their capability from a random approach to an optimized performance by natural selection (agents with long paths die), As the agents develop improved capability (shorter paths), natural selection becomes rare (few agents die), and an emergent collective solution is observed that is better than the performance of an average agent. Natural selection is neither expressed nor important for the higher performance of the system. As the collective, self-organizing structures are incorporated into individual capability within a stable environment, coherence (constraints) arise in the agent's interactions, and the agents lose diversity. The resulting Senescent system exhibits reduced randomness due to the rigid structures and ultimately becomes fragile (all levels are sensitive to noise). With sufficient environmental change the senescent system will return to either the mature or developing stage. |
