The generality of the small-population paradigm in conservation genetics is called into question by a recent report in Current Biology. It has long been thought that loss of genetic variation drives the extinction of isolated populations. However, an analysis of complete genome sequence data from Channel Island foxes (Urocyon littoralis) reveals a striking absence of genome-wide variation in these animals. Island fox populations have persisted over thousands of years despite extremely small population sizes and exhibit a two- to threefold increase in the homozygous state of deleterious variants, such as loss-of-function or missense variants. These findings suggest that selection has not purged harmful variants. Moreover, the San Nicolas Island fox exhibits what the authors call 'genomic flatlining', that is, a near absence of genetic variation, except in a few genes known to have high levels of ancestral variation, for example, olfactory receptor genes.