Self-Organized Critical State

Candidate Law #2:

Community Assembly Reaches a Self-Organized Critical State

A coassembling community of agents, on a short timescale with respect to coevolution, will assemble to a self-organized critical state with some maximum number of species per community. In the vicinity of that maximum, a power law distribution of avalanches of local extinction events will occur. As the maximum is approached the net rate of entry of new species slows, then halts.
--Stuart Kauffman

Kauffman does a good job on this one, maybe because he explains it mathematically without resorting to the biologists' magic evolution incantation ("mutation, recombination, selection").

See also Math and Candidate Laws for Coevolving Systems

— Scotus - 02 Jun 2002