In grad school, I read and learned from Ernst Mayr’s Populations, Species, and Evolution (1963, 1970, Harvard University Press). I think that “Alarming butterflies and go-getter fish” extremely simplifies Mayr’s position on speciation. The article says that Mayr focuses solely on geographic separation, “allopathic speciation.” This ignores the fact that Mayr discussed a variety of other isolating mechanisms besides allopathic speciation.