THE NATURE OF ORDER IN COMPLEX-SYSTEMS

Order in complex systems is investigated within morphodynamics, a theory of evolution considering such systems as ensembles of selectively adaptable components embedded in a random environment. Accordingly, components are specified by pairs of configurational and functional variables submitted to repulsive and attractive interactions; statistical methods of thermodynamics then apply formally. Many order parameters emerge alternatively in the functional space and in the configurational space: a multi-levelled hierarchy is built that describes organization among functions as well as order among structures. Morphodynamics shows that such coordinations arise spontaneously in absence of computations or instructions; instead, they are selected on a basis of internal stability that warrants both high performance and subsidiary adaptation to environmental constraints. Examples are discussed concerning biological order and sensori-motor coordinations.