Echoes of an ancient time in Australia

Exciting results published today in the international science journal Nature provide precious new insights into the arrival and movement of humans across Australia over a staggering 50,000 years. 

Sadly, many Aboriginal Australians no longer live where their ancestors had called home. So to better understand Australia’s history before the arrival of Europeans, a forward-thinking initiative called the Aboriginal Heritage Project was set up. Led by the University of Adelaide’s Australian Centre for Ancient DNA (ACAD) in partnership with the South Australian Museum and Aboriginal families and communities, the team – in which I was fortunate to play a small part – have uncovered some remarkable new findings. 

Headed by Alan Cooper and Ray Tobler, the ACAD group analysed over 100 hair samples collected with consent from Aboriginal people across the continent between the 1920s and 1970s. These samples were collected as part of a project where along with hair, detailed records of the individual, their family and culural heritage were documented by University of Adelaide researchers. 

The hair samples are truly precious, preserving mitochondrial DNA that is inherited through the mother back to the very founding Aboriginal population of Australia. The wonderful thing is the samples allow us to reconstruct a map of Aboriginal Australia before the arrival of Europeans. Crucially, over tens of thousands of years, the genetic code accumulates mutations at a fairly steady rate. This ‘molecular clock’ allows us to date the timing of arrival and migration across the continent. The genetic data revesals a story consistent with published archaeological evidence for human arrival some 50,000 years but give new insights into how the continent was settled over an almost unimaginable length of time.

The peopling of Australia. Genetic groups given by letters.
Ages shown as thousands of years ago (ka). Source: Tobler et al., Nature. 

The new results seem to show that the early population rapidly moved around the eastern and western fringes of Australia. Within just a couple of thousand years they had moved quickly enough  to meet on the other side of the country somewhere near the Eyre Peninsula, South Australia.  But the headline result is that in spite of all the climate and environmental extremes that followed, communities don’t appear to have moved much after this. Genetic differences are found in groups from specific geographic regions and don’t seem to have mixed much at all. Not when the mega-arid ice age occurred 20,000 years ago. Or when sea levels rose dramatically 14,000 years ago. Instead of mass migration, the data suggests communities may have only moved within the immediate region. The basic pattern of effectively held for 50,000 years. No wonder Aborigine communities speak so movingly of their links to country.

A central pillar of the Aboriginal Heritage Project is that Aboriginal families and communities have been closely involved with the project from its inception and that analyses are only conducted with their consent. Importantly, results are first discussed with the families to get Aboriginal perspectives before scientific publication. The research model was developed under the guidance of Aboriginal elders, the Genographic Project, and professional ethicists. This is the first phase of a decade-long project that will allow people with Aboriginal heritage to trace their regional ancestry and reconstruct family genealogical history, and will also assist with the repatriation of Aboriginal artefacts.

“Aboriginal people have always known that we have been on our land since the start of our time,” says Kaurna Elder Mr Lewis O’Brien, who is one of the original hair donors and has been on the advisory group for the study. “But it is important to have science show that to the rest of the world. This is an exciting project and we hope it will help assist those of our people from the Stolen Generation and others to reunite with their families.”

A video on the project and findings can be seen at https://youtu.be/R6LzbKszKhQ


The research article led by Alan Cooper and Ray Tobler is called ‘Aboriginal mitogenomes reveal 50,000 years of regionalism in Australia’ and published today in Nature. There's also a lovely piece by the team in The Conversation at http://theconversation.com/dna-reveals-aboriginal-people-had-a-long-and-settled-connection-to-country-73958. 

Comments

Post a Comment

Popular posts from this blog

The Tropics and the Furious Fifties

Image
There’s an old sailor’s expression: “Below 40 degrees south there is no law, below 50 degrees south there is no God.” Since the sixteenth century, sailors have spoken in awe of the violent westerly winds and seas they experienced fighting their way across the Southern Ocean. With few landmasses to slow them down, the winds found across 40 degrees latitude often reach speeds of twenty-five knots—about 40 percent stronger than their northern hemisphere counterparts—earning them the title the “roaring forties.” As shipping pushed farther south, explorers realized that these winds form part of a vast storm belt that includes the “furious fifties” and “screaming sixties,” names more reminiscent of terrible rock bands than a major part of our planet’s circulation system. The early hunters and traders didn’t understand it at the time, but these winds are created by a procession of low-pressure systems carried east by the jet stream, a river of cold air hurtling and twisting round the Antarct
Read more

Sydney declares a climate emergency – what does that mean in practice?

Sydney declares a climate emergency – what does that mean in practice? Chris Turney , UNSW Late on Monday night, the City of Sydney became the second state capital in Australia (after Hobart a week earlier ) to officially declare a climate emergency . With climate change considered a threat to human life, Sydney councillors unanimously supported a motion put forward by Lord Mayor Clover Moore to mobilise city resources to reduce carbon emissions and minimise the impact of future change. The decision sees Sydney join a variety of local and national governments around the world, in a movement that is increasingly gaining momentum . In total, some 658 local governments around the world have made the same declaration, with the UK and Canada committing their national governments to the global movement in just the past two months . An official declaration of climate emergency puts a government on a “wartime mobilisation” that places climate change at the centre of policy and plannin
Read more

Death of a colony

Image
Cape Denison holds a special place in the history of Antarctic exploration. A small outcrop of rocks on the remote East Antarctic coastline, Cape Denison is forever associated with one of the most spectacular and often forgotten tales of survival. A century ago it was the main base of operations for one of the great explorers of the south: the Australian scientist Sir Douglas Mawson . Privately funded, three bases and one research ship supported a science team that explored a region the size of the United States between 1911 and 1914. Mawson’s Australasian Antarctic Expedition, however, suffered terribly during their time at Cape Denison: a sudden turn of events led to tragedy on the ice, the death of two men, allegations of cannibalism and with the return of winter sea ice, an extended stay in Antarctica. But when they first came upon Cape Denison, Mawson was ecstatic. Greeted by squawking penguins: ‘ We were soon inside a beautiful, miniature harbour completely land-locked. The su
Read more