Dr Alan Wilton of the School of Biotechnology and Biomolecular Sciences, University of New South Wales.
Date: Wednesday, 3rd August, 2005
Time: 6:30 for 7:00 pm
Venue: Conference Room 1, Darlington Centre, City Road
When dingoes arrived in Australia 5,000 years ago they were the domestic dog of the day. Only a limited number of related animals can have been introduced as all current dingoes have very similar DNA types for the mitochondria. The dingo is an example of the early stages of the domestic dog and is more closely related to the Asian dog breeds of today than European domestic dogs.
We have exploited this to identify genetic markers, similar to those used in DNA fingerprinting, that can differentiate dingoes from European dogs. The dingo is an Australian icon that is under threat and disappearing from the wild where it is being replaced by hybrids with domestic dogs. The close relationship of dingoes and dogs means that there are no barriers to interbreeding. The process is difficult to stop and is well advanced along the east coast where most populations contain ~80% hybrids. Isolated populations like the dingoes on Fraser Island may be the only way to preserve the dingo. But first we have to ensure that any population of dingoes we conserve is genetically pure.
Enquiries: Prof. P.A. Williams
or phone the Society - details on Introduction page.
Alan Wilton was born in Sydney in 1953. He got his BSc (Hons) at Sydney Uni in 1976 and PhD in population genetics on Drosophila in 1980 also at Sydney University. He did 5 Postdocs over 11 years in North Carolina State, UC Davis, Univ WA, Adelaide and Macquarie during which time he moved to doing human molecular genetics and disease gene mapping. He has been at University of New South Wales since 1991 and is a Senior Lecturer in genetics in the School of Biotechnology and Biomolecular Sciences. His current research is in disease gene mapping in humans, gestational diabetes and pre-eclampsia. He collaborates with researchers in Norway, Sweden and the US. He has used the information from the dog genome project to identify the genetic cause of a nerve degenerative disease in Border Collies, patented it, and set up DNA testing for the disease allele. He is also working on other dog diseases. His dog disease work has led him to do research into the plight of wild dingoes and the origins of these unique, wild Australian dogs. In 2004 he was awarded the Unsung Hero of Australian Science by the Australian Science Communicators for his work on dingoes. He is Patron of the Border Collie Club of NSW; the Australian Dingo Conservation Association; and the Dingo Sanctuary. He is a member of one of the UNSW Human Ethics Committees. He has 45 scientific publications.
REPORT ON THE GENERAL MONTHLY MEETING
by Jak Kelly
Dr Alan Wilton in his talk "Tails of Dingoes" at the 1137th OGM, described how he and his colleagues at UNSW used gene mapping to find the genetic cause of a nerve degenerative disease in Border Collie dogs and how this led him to study the origin of dingoes, which has been a matter of dispute for decades. Are they wild dogs or once domestic dogs that have gone wild? When and how did they arrive in Australia? Did they walk here over a land bridge, float in on logs, or come in boats? The oldest dated dingo remains are about 3500 years old but bones with characteristic dingo teeth marks on them go back to about 4000 years. There are none in Tasmania so they were not here 12000 years ago. In New Guinea evidence for dogs goes back only 2000 years but it is difficult finding such evidence in tropical forests. Most present day dingoes are dog dingo hybrids but it has been difficult to determine from morphological measurements the degree to which this has occurred in particular cases. Genetic analysis by Dr Wilton and his associates has solved this problem.
The dingo has been both a national icon and an agricultural pest with a price on its head. Fortunately, unlike the Tasmanian thylacine, it has not been driven to extinction and it is now realised that poisoning and trapping the dingo can be a retrograde step for farmers. The social structure of dingoes allows only the dominant female in a pack to breed - thus limiting population growth. Random killing of dingoes breaks down their social structure and the dingoes then breed with any dogs that come along. An intact dingo social structure minimises this and they also kill foxes and feral cats and dogs that enter their territory. This is much better for native wildlife and even farm animals. Dingoes have a large territory which they hunt in sequence and thus do less damage to wildlife than feral cats and dogs that tend to kill indiscriminately.
A kangaroo parasite has been found on dingoes and Asian paria dogs, which suggests dingoes moved back and forth between Australia and Asia on boats as domestic pets and reserve food supplies. Many Asian paria dogs look like dingoes, further reinforcing the idea that they were originally Asian domestic dogs which went wild here after arriving on Asian boats.
Genetic analysis, in particular, on a section of mitochondria which can mutate without damaging the body, as it does not make a protein, can be used for dating. The larger the number of mutations the older it is. Amplification of selected sections of DNA, to make millions of copies, enables DNA sequencing which shows relationships between species. For example, it has shown that whales come from cows. It the case of dingoes it shows that they are more closely related to domestic dogs than to wolves and closer to Asian dogs than European dogs. These results also indicate that dogs were domesticated in Asia at an earlier time than they were in Europe.
Because of cross breeding with domestic dogs, few pure breed dingoes are left, particularly along the east coast. The UNSW team have used genetic markers, like those used in paternity checks, to find that there is not much genetic variation between all dingoes, thus indicating that they are all descended from a small number of ancestors who probably escaped from the boats of Asian traders about 5000 years ago.
In making efforts to conserve the dingo, we should be sure we are saving the pure bred strain. Everywhere they are becoming less afraid of man and indeed attracted to parks and resorts as a food source. One of the few remaining pure groups is on Fraser Island, as genetic analysis confirms but how long they will remain so is a matter of concern.