An SBS television documentary has used DNA to trace the ancestry of three high profile Australians, showing how important genetics is in understanding our past and our present.
DNA Nation was produced by Blackfella Films and features former Olympic champion Ian Thorpe, television personality Julia Zemiro and actor Ernie Dingo, who each gave a sample for analysis via a cheek swab.
As part of the program, a “DNA census” testing everyday Australians was also conducted. Australians from Greek, Anglo-Celtic, Indigenous, Chinese, Indian and Lebanese ethnic groups took part giving DNA samples in the first survey of its kind to be conducted in Australia.
There was distinct genetic diversity within these groups, despite their strong cultural identities. Interestingly the group where the least diversity was found was the Chinese Australians. For the past few thousand years there was little migration into China allowing their gene pool to remain isolated, unlike in Europe where immigration, and therefore the mixing of different genetic lines, was commonplace.
For Ian, Julia and Ernie, the analysis looked at the Y chromosome passed down from father to son, and their mitochondrial DNA, which is passed down the female line.
The program begins with the first finding from the participants’ mitochondrial DNA taking them to meet the Hadzabe people in Tanzania. These are hunter gatherer people and the area in which they live is thought to be possibly where the first woman – from whom all modern mitochondrial DNAs are descended – lived two hundred thousand years ago. She is known as “Mitochondrial Eve”.
The series consultant, Dr John Mitchell is an Associate Professor of Genetics and Anthropology at La Trobe University. Dr Mitchell guided the participants and the audience on this DNA journey.
“Not everyone would be aware that all human ancestry goes back to East Africa. These are the first people that we are all descended from,” he said.
The celebrities then travelled to Arabia using the route their ancestors took around 70,000 years ago, across the Red Sea from Africa. From here their journeys began to branch off; Ernie followed his mother’s line first to India and then Timor Leste before returning to Australia. Julia’s journey took in Turkey, Israel, Sardinia and England while Ian visited Turkey, Israel, Kyrgyzstan and Scotland.
In Timor Leste, Ernie was proud to discover that his ancestors made the first major sea crossing by humans of around 90 kilometres, from what is now Timor Leste to Australia, around 50,000 years ago.
After discovering that he had further seafaring heritage via Viking DNA from Scandinavian ancestors on his father’s side, Ernie returned to Australia to learn that he is descended through an unbroken female line on his mother’s side from a rare branch of the human DNA tree known as M15. Around 40,000 years ago a woman of the M15 line came to Western Australia and started a family; Ernie’s mother’s ancestors have lived there ever since.
In Turkey, Julia and Ian were able to visit a large archaeological dig and saw the bones of their ancestors, dated from around 400 generations ago, uncovered from where they were buried beneath the homes of their families.
Julia discovered that she is partly descended from the Phoenicians – “peaceful conquerors” that dominated the Mediterranean around 3,000 years ago. They were seafaring traders that invented the modern alphabet. Julia travelled to Sardinia where she took part in extracting a tooth from a 2,500-year-old skeleton discovered at a Phoenician settlement. The tooth would be used for DNA testing to find out more about these ancient people.
Ian and Julia were also able to visit their present day ‘genetic cousins’. On testing nucleotides found in Julia’s mitochondrial DNA (all 16,569 of them) Dr Mitchell discovered a sailmaker named Claire in Devon, England whose results were the same as Julia’s except for one nucleotide. The term ‘genetic cousins’ is used because these results show the two women share a common ancestor from possibly as recently as 300 years ago.
Ian learned that his ancestry on his father’s side goes back to the Russian Steppes and the Ukraine where it’s thought the Yamnaya people may have been responsible for domesticating horses and perhaps even inventing the wheel, enabling them to travel and migrate to Europe.
As part of the documentary, Ian was sent to Kyrgyzstan because this is the ideal place today to see and experience the life of his ancestors around 5000 years ago.
The horses the Yamnaya domesticated and used for agriculture and transport were also milked for food, and this is linked to an important genetic trait that was passed down to northern Europeans. That trait is the ability to digest milk as an adult.
Lactose intolerance is quite rare in infants but as humans grow we naturally produce less lactase. In many Europeans, however, the lactase activity continues into adulthood. There are certain inherited genetic variations that control lactase production and how well someone can digest dairy products. It’s thought that these variations could be traced back to the Yamnaya people.
Pathology testing is important for people experiencing gastro-intestinal symptoms that may be caused by lactose intolerance. A hydrogen breath test can be used to diagnose lactose malabsorption and further tests may be needed to rule out serious conditions with similar symptoms, for example coeliac disease or ulcerative colitis.
From Kygryzstan, Ian travelled to Scotland to meet his genetic cousin Anna.
Jacob Hickey of Blackfella Films, the producer of the series, said that the journey was absorbing for everyone involved.
“What was so enthralling about making the show was the opportunity to look at how much we share and how much common ground we have. It was so exciting to see science and history coming together; science was the key to the door of 200,000 years of history.
We spend so much time focusing on our differences, but this DNA journey really is the story of humankind – that is inside all of us.”
Dr Mitchell said, “We know quite a bit about human ancestry, we were able to trace a genetic journey for these celebrities, but it’s not their distinct journey – many people’s journey would be the same. I hope this comes across in the program.”