On hypothesis testing in ecology and evolution.

Abstract

The aim of biological research typically is to assess the relative contributions of a number of potential causal agents operating simultaneously. Sensibly stated hypotheses in the methodology of most field investigations are not intended to be mutually exclusive, in any sense exhaustive, or global in their application. It is not possible in principle to perform a 'critical test' or experiment to distinguish between the truth of 'alternative hypotheses' if the proposed causal processes they caricature occur simultaneously. Examples are considered in which a rigid hypothetico-deductive methodology applied to nonalternative ecological 'hypotheses' could lead to fallacious conclusions. It has been proposed that processes of ecological succession may be separated into alternative modes of 'facilitation', 'inhibition' and 'tolerance'. Yet attempts to experimentally reject one or more of the supposedly distinct hypotheses cannot, in principle, distinguish between them in a variety of biologically interesting cases. Particular problems arise when 'null models' in ecology are treated as hypotheses of 'strong inference'.-from Authors