Far from inspiring that paradigmatic shift in economics that was envisioned by its early proponents, 'evolutionary' economics today represents a patchwork of unconnected theories and topics. In other disciplines, evolutionary thinking has induced a paradigm shift, resulting from the adoption of the Darwinian paradigm extended by hypotheses about cultural evolution. Concerning economics, however, even a preliminary discourse on the potential of this paradigm for future theorizing remains controversial. The present paper therefore focuses on the methodological implications of the paradigm. It is shown that hitherto unnoticed common ground can be identified underlying the diversity of approaches to evolutionary economics. It rests in the modalities of causal explanations germane to the Darwinian paradigm. Understanding these modalities also makes it possible to distinguish evolutionary from non-evolutionary research irrespective of the specific theories and topics concerned. The argument is illustrated for the exemplary case of institutional economics.