The competitionist paradigm

The tradition of explaining community patterns as products of interspecific competition has shaped numerous research programs over the past several decades. Many ecologists have assumed that competition has been a potent selective factor over evolutionary time, and have considered it to be a potentially major interaction in contemporary communities. Interest in competition has been pervasive; it has defined the research programs of theoreticians and shaped the studies of empiricists, who have employed widely accepted approaches to measuring and explaining niche differences and patterns of overlap in nature. The pervasiveness of the focus on competition prompted Strong (1980) to describe competition as a paradigm in Kuhn's (1962) sense of a ‘characteristic set of beliefs and preconceptions,’ which includes ‘instrumental, theoretical, and metaphysical commitments together’ (Kuhn 1974). Acceptance of the central importance of interspecific competition was never universal (e.g. Andrewartha & Birch 1954), and recently opposition to the pervasiveness of the concept has increased (e.g. Connell 1975, 1980, Wiens 1977, exchange of views in Strong et al. 1984). Simberloff (1982) severely criticized the central role of competition theory as having ‘caused a generation of ecologists to waste a monumental amount of time.’ Critics have focused upon the lack of attention to alternative hypotheses to competition, particularly in the absence of widespread field experimentation establishing the prevalence of interspecific competition in many natural communities. Criticisms such as Simberloff's are too harsh in light of the accumulating experimental evidence of competition in some communities (Connell 1983, Schoener 1983a), yet it is by no means clear that interspecific competition is pervasive in natural communities.