Geomorphologists have an insiders' joke that I'll share here, as Eos garners a particularly appropriate audience: “There are as many geomorphologists who think that they're doing geophysics as there are geophysicists who think that they're doing geomorphology, but neither group is doing it very well.”The allegation misrepresents the truth, of course, but it does reflect upon a trend that grew throughout the 20th century. For several decades, scientists with diverse training have investigated the interactions between endogenic (crustal movements and volcanism) and exogenic (weathering, denudation, and sediment transport) processes. Despite the claim of the preceding allegation, their work has led to a better understanding of landform development.