The spread of chytridiomycosis is causing the decline and extinction of many amphibian species worldwide. In a paper in this issue of Frontiers of Biogeography, Banks and colleagues show that the populations of south-east Australian alpine tree frog (Litoria verreauxii alpina) surviving the infection hold similar genetic diversity as unaffected ones, and that individuals with greater heterozygosity present reduced probability of infection. Photo credit: David Hunter.