INTER PLAY OF CAUSATION BETWEEN SUPPLIERS AND CONSUMERS IN EVOLUTIONARY TROPHIC DYNAMICS

Natural selection, conceived as the process of small causes making sma ll effects on the level of molecular evolutionary dynamics of a popula tion, can yield global effects on the level of evolutionary trophic dy namics of populations, including those of mass extinctions. Occurrence of mass extinctions is due to the interplay of causation between supp liers and consumers in trophic dynamics. If the case of supplier causa tion is available such that resource exploitation by consumers on the upper trophic level follows in time resource presentation by suppliers on the lower, instead of resource exploitation followed by resource p resentation, mass extinctions could be a norm of the evolutionary trop hic dynamics. (C) 1997 Elsevier Science Ireland Ltd.