Resource partition history and evolutionary specialization of subunits in complex systems

Specialization for part of the resources available is a common adaptation l eading to diversification in biological systems. In complex ecological comm unities, the history of diversification of parts of a system correlates wit h the structure of the system in present times. Abundances and sequences of resource partition of species expected by a sequential broken stick model are compared with observed abundances of species and their sequences of evo lutionary divergence. Where resources are abundant, first resource partitio ns correspond to most ancient speciations, and last to recent speciations. The inverse is true when resources are scarce, agreeing with the occupation of extreme habitats by recent species. Diverging species seem to specializ e by dividing the niche of common ancestors. Similar trends exist inside ge nera as well as between families, suggesting similar patterns in diversific ation and specialization at other levels of biological organization, such a s evolution of functional complexes of macromolecules and organs embryogene sis. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.