A genetically isolated dingo population in western Victoria, Australia, reveals greater structuring of the Australian dingo

The Australian dingo is a relatively recent anthropogenic addition to the
Australian fauna, which spread rapidly across the continent and has since
widely interbred with modern dogs. Genetic studies of dingoes have given
rise to speculation about their entry to the continent and subsequent
biogeographic effects, but few studies of their contemporary population
structure have been conducted. Here we investigated the dingo ancestry and
population structure of free-living dogs in western Victoria and
contrasted it with a wider southern Australian sample. We wished to
determine whether their geographic isolation was mirrored in genetic
isolation. To address this question, we analysed genetic data using
Bayesian clustering and discriminant analysis of principal components, and
summarised genetic diversity at the population and individual levels. Upon
finding low genetic diversity in western Victoria, we tested for a recent
genetic bottleneck. The broader southern Australia sample (n=1,138)
comprised mostly hybrid animals, with ~30% dingoes. All western Victorian
individuals (n= 59) appeared to be hybrids with high dingo ancestry. The
population showed no evidence of admixture with other populations and no
recent bottleneck. Based upon our characterisation of this unusual
mainland population, we sound caution for future studies assuming
homogeneity of dingoes across the continent.