Ecological laws: what would they be and why would they matter?

There remains considerable debate over the existence of ecological laws. However, this debate has not made use of an adequate account of what a relationship would have to be like in order for it to qualify as an ecological law. As a result, confusions have persisted not only over how to show that ecological laws do (or do not) exist, but also regarding why their existence would matter - other than to whether ecology looks like physics. I argue that ecological laws would have to possess collectively a distinctive kind of invariance under counterfactual perturbations. I call this invariance "stability." A law of physics, such as the law that all bodies travel no faster than the speed of light, is not only true, but also necessary in a physically significant sense. (A body must travel no faster than light; it couldn't do otherwise, even if it were subjected to a greater force.) Likewise, the stability of ecological laws would render them necessary in an ecologically relevant sense. Furthermore, ecological laws would differ from fundamental laws of physics in the range of counterfactual perturbations under which they are invariant. Therefore, I argue, the existence of ecological laws would make ecological explanations irreducible to even the most complete possible physical explanations of the same phenomena. Ecological laws would make ecology genuinely autonomous from physics.