On principles, laws and theory in population ecology

Several commentaries have appeared recently on the status of ecology as a science, with some being quite pessimistic when comparing ecology to the hard sciences like physics. For example, some ecologists wonder if we will ever have general laws and theories (Roughgarden 1998, Lawton 1999) or become a predictive science (McIntosh 1985, Peters 1991). The reason for this, says Murray (1992), is that ‘‘biologists do not think like physicists’’. Others think that ecology is just too variable and complicated to be subject to general theory (Hansson 2003). Some are more optimistic. For example, Ginzburg (1986) shows how ecologists can and do think like physicists and suggests that, by thinking this way, we can open new doors to ecological understanding (see also Colyvan and Ginzburg 2003Colyvan and Ginzburg 2003b, Ginzburg and Colyvan 2003). Berryman (1999) claims that population ecology already has a set of well-defined principles that are sufficient to describe, classify and explain all known patterns of population dynamics. Turchin (2001) and Colyvan and Ginzburg (2003a) are of a similar mind, suggesting that we may already have general laws resembling those of classical physics. In this paper I continue the philosophical debate from my particular point of view, and also attempt to clarify and consolidate differing views about ecology and its relation to the physical sciences.