A detailed picture of the origin of the Australian dingo, obtained from the study of mitochondrial DNA

Abstract

To determine the origin and time of arrival to Australia of the dingo, 582 bp of the mtDNA control region were analyzed in 211 Australian dingoes sampled in all states of Australia, 676 dogs from all continents, and 38 Eurasian wolves, and 263 bp were analyzed in 19 pre-European archaeological dog samples from Polynesia. We found that all mtDNA sequences among dingoes were either identical to or differing by a single substitution from a single mtDNA type, A29. This mtDNA type, which was present in >50% of the dingoes, was found also among domestic dogs, but only in dogs from East Asia and Arctic America, whereas 18 of the 19 other types were unique to dingoes. The mean genetic distance to A29 among the dingo mtDNA sequences indicates an origin approximately 5,000 years ago. From these results a detailed scenario of the origin and history of the dingo can be derived: dingoes have an origin from domesticated dogs coming from East Asia, possibly in connection with the Austronesian expansion into Island Southeast Asia. They were introduced from a small population of dogs, possibly at a single occasion, and have since lived isolated from other dog populations.

Fig. 1.

Genetic relationships between mtDNA control region sequences (582 bp) from dingoes, domestic dogs, and wolves. (A) Phylogenetic tree showing all dog, wolf, and dingo mtDNA types. Unlabeled leaves denote mtDNA types from domestic dogs, yellow circles denote types unique to dingoes, red circles denote types found in both dingo and dog, and squares denote wolf mtDNA types. The tree is rooted to coyote sequences. Dog clades A–F are indicated with letters. (B) Minimum-spanning network of the main dog clade (clade A). Sequence types (circles) and empty nodes (solid dots) are separated by one mutational step (substitutions; indels are not shown). The mtDNA type indicated by bold lines has four shortest links (with a length of three mutational steps) to other mtDNA types, but two of these are not shown to simplify the figure. Yellow, unique dingo mtDNA type; red, type found in both dingo and dog; blue, type found in dogs in Indonesia, the Philippines, or Malaysia; green, unique New Guinea type. Squares denote wolves. Areas of red and yellow circles are proportional to frequencies among dingoes, but the area of A29 is reduced by 50%.