The concept of ecological speciation invokes Darwinian natural selection as a means of generating biodiversity and, specifically, reproductive isolation (Rundle and Nosil (2005) Ecol. Letts 8). Patten (2008) J. Biogeog. 35, 1 argues that speciation and specialization, ‘long studied as distinct disciplines, one evolutionary, the other ecological’, could well be ‘one and the same thing’.