Ecology emerged as a self-conscious discipline during the last decade of the nineteenth century, growing out of a heterogeneous mix of fields. Indeed, its roots are as different as field natural history and experimental physiology. 1 Given that ecology was (and remains) such a heterogeneous enterprise, it is unlikely that any single perspective will suffice to describe its history. Several very different approaches have already proved fruitful. Ronald Tobey has discussed the changing importance of applied versus non-mission-oriented research in the development of ecology. Sharon Kingsland has emphasized the relative merits of theoretical versus empirical research at various points in the history of the discipline. Robert McIntosh has taken the very heterogeneity of the discipline as his perspective on its history} The papers that follow approach the history of ecology from yet another standpoint, namely, the changing role of evolutionary theory in the solution of ecological problems. In On the Origin o f Species Darwin frequently brought evolu-