THE NATURE OF ORDER IN COMPLEX-SYSTEMS

Order in complex systems is investigated within morphodynamics, a theo ry of evolution considering such systems as ensembles of selectively a daptable components embedded in a random environment. Accordingly, com ponents are specified by pairs of configurational and functional varia bles submitted to repulsive and attractive interactions; statistical m ethods of thermodynamics then apply formally. Many order parameters em erge 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 sho ws that such coordinations arise spontaneously in absence of computati ons or instructions; instead, they are selected on a basis of internal stability that warrants both high performance and subsidiary adaptati on to environmental constraints. Examples are discussed concerning bio logical order and sensori-motor coordinations.