Oral histories help connect Australia's Aboriginal and Torres Strait Islander people with their ancestors, and with the past.

Today, these oral traditions are helping to shed light on how the Australian continent changed throughout major geological events.

Dr Karl explains how science and indigenous knowledge are coming together to better understand Australia's history.

Dr Karl: Many indigenous populations around the world did not have written languages — at least, as we understand them today. Instead, their knowledge was often passed down through generations by spoken, or oral tradition. But could they keep this knowledge intact over the generations? I mean it's hard enough to keep a story straight over a few days, let alone thousands of years!

Well, Australian Aboriginal people have accurately passed down information from one generation to the next, for over 10,000 years. That's partly because this knowledge is often embedded in songs and dances, which are harder to change than a spoken story. And how do we know their oral history has remained accurate? By comparing that history to known geological events.

Way back, at the end of the last Ice Age, we had a totally verifiable event that affected the entire Australian coastline. This "event" was the rising of ocean sea levels. A big flooding event easily makes it into the oral record because it's cataclysmic, and greatly impacts people's lives.

The first Australian Aboriginal people arrived on the continent about 60,000 years ago. Our most recent Ice Age reached its peak around 26,000 years ago. At that point, glaciers covered huge tracts of land around the world. The ice was about one kilometre thick over New York, and even the Great Dividing Range in Australia was capped with glaciers. The water for this ice came out of the oceans — and so during the Ice Age, the ocean level around the world dropped by about 120 metres. The world started warming out of this last Ice Age a bit over 20,000 years ago. As the ice on land melted, the ocean levels rose. We had peak ocean levels around 6-7,000 years ago. Since then they stabilized, and then fell slightly.

Thanks to geological records, we are very confident about the timing of the ocean level rises. And there are many Aboriginal oral traditions that describe this rise, and an associated loss of coastline. By matching both historical records, we can accurately time the big events mentioned in the stories.

For example, look at Rottnest Island in WA. It's about 18 kilometres offshore, west of Perth. But it wasn't always an island - one Aboriginal story says Rottnest Island, "once formed part of the mainland ... and the sea rushed in between, cutting off these islands from the mainland". The deepest part of the ocean floor between the mainland and Rottnest Island is about 7-8 metres. So, using geological data, we know this event must date to a time about 8000 years before the present.

Another example comes from the Spencer Gulf in South Australia. The Narungga people have a story saying that the gulf was previously a broad and flat floodplain with a line of fresh-water lagoons. The plain stretched inland from the ocean for nearly 200 km — but it was eventually flooded by incoming seawater from the rising ocean levels. Depending on how you define how the Spencer Gulf flooded, we can date this event to somewhere between 9,700 and 12,000 years ago.

There are similar oral histories all around the Australian coastline.

One tradition from Fitzroy Island off the coast of Cairns probably dates back to a time when the ocean was 65 metres lower — so using geological data we can assume that event occurred about 13,000 years ago. Another oral history refers to the water rising and separating Bathurst Island and Melville Island from mainland Northern Territory. For the islands to be connected, the sea level would have been 12-15 metres lower than today, so this oral history has to go back around 9000 years. In Victoria, numerous traditions refer to, what is now, Port Philip Bay as being a good place to catch many kangaroos and possums. So, it definitely wasn't a bay back then! In this case, the ocean level rise tells us that that land became a bay about 7,200 years ago.

It's important to realise that for indigenous societies around the world, oral histories are not fairy tales or just legends.

First, the words that are passed down through generations are ritually and deeply embedded in cultural practice. The stories carry with them explicit teachings of Laws, as well as responsibilities. These stories build in the principle of "unchangedness", to ensure successful transmission of traditions from one generation to the next. Oral traditions cover a broad range - from stories to help little children to go to sleep, to rules to live by, survival advice and yes, straight historical facts without any embellishments.

And the indigenous oral traditions of historical events can give us a better understanding of natural phenomena today. So, while the tides have ebbed and flowed, these stories have stayed the same.

Name _________________________ Aboriginal Memory

1. Explain “oral tradition.” (2 marks)

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2. How do we measure the accuracy of Aboriginal stories? (2 marks)

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3. When did Rottnest become an island? (3 marks)

4. How long ago did people hunt kangaroo in Port Philip Bay? (3 marks)

5. List two aspects of the oral tradition. (4 marks)

6. Summarise “Aboriginal Memory,” in your own words.(6 marks)

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