title: Importance of diversity. Reconciling natural selection and noncompetitive processes.
abstract: To better understand selection processes in evolutionary systems (ecological to economic to social to artificial systems), the origins and role of diversity are examined in two systems that show increased group functionality (better performance, efficiency, robustness, adaptability, stability, etc.). Diversity was chosen as a clarifying concept, because it appears to have been largely ignored, or misunderstood. One system is a model of group selection within an ecosystem. The other is the group solution of a sequential problem using self-organizing dynamics in the absence of any selection. A comparison of the two systems show that while diversity is essential to both, improvement by natural selection is derived from consuming diversity, whereas improvement by noncompetitive self-organization is decreased by any reduction in diversity. The resulting perspective is that natural selection is a mechanism that increases the functionality of the individual (or groups within a larger system); noncompetitive self-organization of the system, without need for selection, increases the functionality of the whole above that of the individual or group. The two extreme roles for diversity are reconciled if natural selection is not strongly expressed in these systems--"survival of the fittest" becomes "survival of the adequate"--so that noncompetitive processes can occur. The resulting view of a mature ecosystem is an elastic web of interactions in which natural selection is dormant or retains the status quo. The processes of natural selection for individual or group improvement are activated only if environment changes are sufficient to break the elastic interconnections, as might occur in punctuated equilibria.
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, New Mexico 87545, USA. nlj@lanl.gov
authors.forename: N L
authors.initials: NL
authors.lastname: Johnson
mesh_terms: D000818:Animals; D017753:Ecosystem; D014644:Genetic Variation; D006801:Humans; D007858:Learning; D012641:Selection, Genetic