Structural stability can shape biological evolution

We analyze a model of biological evolution recently introduced in the liter ature and show that punctuated equilibrium and power-law behavior arise bec ause of the differential structural stability of the mapping between genoty pe and phenotype that characterizes the model. Structural stability is a fe ature of biological organisms that had been introduced by biologists long a go, but never modelled until now, as far as we know. This model can be rega rded as an alternative to those models that explain both the power-law beha vior and the punctuated equilibrium of extinction curves by recourse to sel f-organized criticality (SOC). (C) 2000 Elsevier Science B.V. All rights re served.