  The origin of macroscopic complexity is traced in a wide range of systems
(imunology, ecology, finance, marketing, etc) to the discrete and
auto-catalytic (i.e. multiplicative) character of their elementary components.
Even in the simplest conditions which naively would lead to the complete
"death" of any dynamics, these 2 properties lead to the emergence of
self-organized adaptive collective objects. In turn, these objects insure the
survival of a very rich and unexpectedly resilient macroscopic "life".
