New DNA evidence shows dingoes are almost 90% pure – and fall into eight distinct groups
- Written by The Conversation
Dingoes have roamed Australia for at least 3,000 years. These clever canines are the mainland’s only native apex predator on land. They also hold deep cultural and spiritual meaning for many First Nations groups.
When European colonists arrived, they brought domestic dogs. These have sporadically bred with some dingo populations and introduced their genes.
Dingoes evolved as a unique canine branch for thousands of years, and have developed a distinct genetic arsenal to adapt to Australian environments.
At present, authorities generally manage free-roaming canines under the broad label “wild dogs”. This term can include dingoes, stray domestic dogs and dingo-dog hybrids.
The genetic tests used to quantify the amount of dog ancestry in dingoes so far have given conflicting results, leaving agencies unsure which estimates to trust.
So how much genetic influence have domestic dogs had? In our new research, we build on our earlier work on ancient dingo DNA to develop a more accurate test for dingo ancestry.
Our tests of over 300 free-roaming canines around Australia shows most carry overwhelmingly dingo ancestry. On average, these canines are 88.3% dingo and just 11.7% domestic dog.
The missing piece: a true ancestral reference
In recent years, researchers have expanded our knowledge of dingoes.
Major steps include genome-wide studies using nearly 200,000 DNA markers, rather than the small number of markers used in some older tests.
But all earlier approaches have a common limitation: the use of living dingoes as the genetic reference. These animals were assumed to be free of dog ancestry.
The problem is that if these dingoes had any dog ancestry, the statistical methods used would then mistakenly identify dog ancestry as “dingo”.
In a previous study, we extracted DNA from dingo remains estimated at up to 2,746 years old. These ancient genomes give us a true baseline. They predate European arrival – and the introduction of European dogs – by thousands of years.
Using this ancient dingo DNA gives us a sharper, clearer picture of more recent changes to dingo genetics.
Ancient DNA lets us tease apart two questions often difficult to answer with modern DNA alone. How much domestic dog ancestry does a given animal have? And how much dingo-specific genetic diversity remains in an individual?
Both questions are important for their conservation and management.
Geography and human settlement shape gene flows
Our research shows dingoes living closer to towns, cities and farms tend to show more dog ancestry. Away from these areas, dog ancestry is much lower.
The influence of domestic dogs was highest in southeastern Australia, especially Victoria and New South Wales.
This supports recent work showing the influence of dogs on dingoes peaked in the 1960s and has since fallen. That decade saw rapid human population growth in southeastern Australia, and farming intensification after the Second World War.
Dingoes are not a single genetic population
In our earlier study, we showed dingoes split into eastern and western groups long before Europeans arrived. The Great Dividing Range marks the divide.
Our new research on over 300 individual animals allows us to drill down much deeper. There aren’t just two distinct groups of dingoes – there are eight. Further sampling might uncover more groups.
Two of these groups were not previously known to be distinct – those in northern and central Australia.
Several dingo groups carry very low levels of dog ancestry, with standouts being North (~2.9%), West (~2.9%), Central (~5.6%) and K'gari (~1.3%).
Could domestic dog genes be useful to dingoes?
Our findings that dingoes average almost 90% dingo genes has a hidden benefit.
Some dingo populations, such as the Mallee group in Western Victoria, are in drastic decline. When numbers fall, so does the group’s genetic diversity.
Healthy animal populations have high genetic diversity, meaning they have more raw material to respond to new pressures when their environment changes. It improves the odds they can cope with future challenges.
For dingo groups on the edge, dog genes boost genetic diversity and could even help reduce the effects of drastic population decline. But it’s not certain – we don’t know whether the benefits of increased genetic diversity outweigh the replacement of dingo ancestry.
Southeastern dingoes face genetic challenges
We found the dingoes of Australia’s southeast had much lower dingo-specific genetic diversity, especially Mallee dingoes in Victoria’s Big Desert national park.
This means dog ancestry isn’t simply “good” or “bad”. Flows of dog genes can boost diversity in inbred or declining dingo populations. But too much reliance would mean losing what makes dingoes distinct.
Authorities face a difficult task when it comes to managing dingoes.
Our research can help accurately estimating the level of ancestral dingo genes carried by current dingo populations. This data can help guide conservation and management decisions, though it should not be used as a single threshold of “dingo-ness”.
Wild dogs are dingoes
It can be convenient for farmers and wildlife agencies to dub an animal a “wild dog” if it’s attacking sheep. But it’s very unlikely to be the right term.
Australia’s free-roaming canines are vastly more dingo than they are domestic dog, as our genetic work shows.
But there are important regional differences. Future efforts to manage these animals should be done by region, working alongside First Nations communities.
