Though they are often seen as foils for each other, ecology and agricultural science co-evolved. With shared roots in late nineteenth-century botany, ecologists and agronomists fostered important connections during the Progressive Era that have been largely overlooked despite a number of finely nuanced studies of ecology's origins. But if “applied ecology” once effectively meant agriculture, over the course of the first decades of the twentieth century the relationship between ecology and scientific agriculture grew strained. Agriculturists narrowed their focus to increasing yields, and ecologists sought to establish their discipline as a distinct theoretical science and so distanced themselves from its agricultural applications. By the end of World War I, the process of disciplinary specialization was well underway. In time the two disciplines diverged so completely that the once vital connections between them were obscured and forgotten.