This paper investigates the dynamics of a complex adaptive supply network (CASN), focusing on understanding stability of the structural evolution of a supply network and supplier population emergence. Supply network evolution data collected from simulated responses of the U.S. automobile industry are used in multivariate statistics and time series analysis to identify patterns of network evolution. This analysis reveals that the type of environment a supply network evolves in appears to be a major factor in determining critical timing of structural changes during the evolution of a CASN. Further, time series analysis of firm population evolution highlights how supply networks evolve due to path dependencies in the CASN system. Information about these two aspects of supply network evolution can prove useful to a decision maker in determining how to respond to supply network changes.