An isolated population reveals greater genetic structuring of the Australian dingo

Abstract

The Australian dingo is a 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 34 microsatellite markers using Bayesian clustering and discriminant analysis of principal components, and summarised genetic diversity at the population and individual level. The broader southern Australia sample (n = 1138) comprised mostly hybrid animals, with 30% considered pure 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 low genetic diversity on all measures tested. Based upon our characterisation of this unusual mainland population, we advise against assuming homogeneity of dingoes across the continent.

Genome‐wide variant analyses reveal new patterns of admixture and population structure in Australian dingoes

“…We observed elevated homozygosity levels (median F het > 0.7) in the Big Desert compared to other dingo populations, suggesting the population is experiencing inbreeding (Figure 5). A recent microsatellite‐based study found the Big Desert dingo population to have genetic diversity levels up to 50% lower than other dingo populations (Stephens et al, 2022). While the absolute value of homozygosity measures calculated for dingoes in this study could be inflated due to ascertainment bias, whole genome data from a small number of captive and wild dingoes also reveal elevated homozygosity levels relative to domestic dogs (Field et al, 2022; Kumar et al, 2023; Zhang et al, 2020).…”

Stable dingo population structure and purity over 11 years of lethal management

“…In addition, populations of dingoes with documented isolation and decreased genetic diversity, such as those on K’gari/Fraser Island (Conroy et al . 2021) and in western Victoria (Stephens et al . 2022), currently persist without noticeable negative effects.…”

“…Although fragmenting populations can sometimes spur conservation concerns associated with low genetic diversity (Blanchet et al 2010), we believe this is unlikely to be a concern for dingoes in this instance; their large movement capabilities and rapid expansion across the continent since their relatively recent introduction from a small founder population indicates persistence and adaptability, despite relatively low genetic variation (Wilton et al 1999;Zhang et al 2020). In addition, populations of dingoes with documented isolation and decreased genetic diversity, such as those on K'gari/Fraser Island (Conroy et al 2021) and in western Victoria (Stephens et al 2022), currently persist without noticeable negative effects.…”

Activity of dingoes (Canis familiaris) and their use of anthropogenic resources in the Strzelecki Desert, South Australia

“…In accordance with animal ethics approval, morphological data were collected and a biopsy was collected from the ear with an Allflex sampling kit ® and analysed by an independent laboratory Zoological Genetics (South Australia) by using microsatellites (Wilton 2001;Stephens et al 2015). DNA analysis was undertaken to assess kin and subpopulation relationships within the population and elsewhere across Australia, so as to gain understanding of family relationships and lineage (Stephens et al 2022). A small, coloured ear tag was fitted into the biopsy hole to aid identification at a distance and a microchip was inserted into the nape.…”