Digging up the past
When Alan Cooper was a youth in New Zealand, exploring caves and using bones of the giant extinct moa bird to dig through rockfalls, he had little idea this would lead to an international career.
Twenty years down the track, the zoology professor heads a new world-leading research unit at the University of Adelaide, which hopes to answer some of Australia's most important evolutionary questions.
Professor Cooper has spent the past year establishing the Australian Centre for Ancient DNA, due to be officially opened on 24 July, 2006.
He was lured from Oxford University in early 2005 after winning a prestigious ARC Federation Fellowship and joining the University's School of Earth and Environmental Sciences.
The new hi-tech centre will provide a research facility for ancient DNA studies in the southern hemisphere, helping scientists to understand Australia's past and better manage its future.
To the layperson, ancient DNA is best described as genetic material from the past which has been preserved. It is DNA which has been left behind in bones, teeth, droppings and even dirt.
Australia's extreme heat, compared to Europe and North America, makes ancient DNA research much more difficult as it accelerates the degradation of genetic material.
Professor Cooper and his team hope to work with specimens in Australia dating back 60,000 years.
"Radiocarbon dating (a method used to obtain age estimates on organic materials) is only effective up to about 60,000 years," he said. "Even to get to this age, we'll need to focus on colder environments such as Tasmania, mountains in New Guinea, Antarctica of course, and possibly certain marine environments.
"A common mistake is to think that we're getting DNA from things like dinosaurs à la Jurassic Park, which died out over 65 million years ago.
Obviously we're not, and the upper limit for survival under ideal deep frozen conditions is probably only about half a million years. However, we can use the ancient genetic information to study much older events, by combining with the fossil record and extrapolating backwards."
Ancient DNA can be used to study how populations and species have changed over time in response to major environmental events, such as mass extinctions, climate change and human impact.
"There are a lot of physical measurements about past climatic conditions--from ice cores and deep sea sediments--but often we're more interested in the actual impact those changes had on species. Ancient DNA allows us to access that information.
"For example, our work on permafrost-preserved megafauna in Alaska and Canada showed the last glacial ice age around 22,000 years ago resulted in the decimation of the bison population and many other species."
But it's global warming that has scientists worried as the world enters the 21st century.
"Part of our research will involve analysing ancient DNA records to reveal the likely responses of species and populations to major climatic changes--in this case global warming."
Australia's climate makes it difficult to recover ancient DNA from the extinct giant marsupials of the mainland, but Professor Cooper believes Tasmania could still yield some fascinating discoveries.
"Tasmania has still got a lot of material buried in its caves. We are working with some of the cavers in the north-west of Tasmania and hope to recover DNA from some of the giant marsupials there."
The other area expected to provide evolutionary answers for Professor Cooper's team will come from dirt and the detritus--ecological dandruff --which it contains.
"Sediments tend to preserve genetic records. We'll be looking at the Coorong, river systems, lakes and deep sea sediments because everywhere we look there are preserved DNA records. These records can tell us a lot about past environmental changes and also provide information about pre-Aboriginal and pre-European environments.
"On a world scale, Australia's experience with ancient DNA is not high. But there are some very important evolutionary questions down here, involving issues such as climate change, the evolution of the unique Australian biota, and the origin of Aborigines.
"We are also studying the evolution and spread of humans around the world, as part of the National Geographic's Genographic Project. We're examining samples from Neandertals and the `hobbits' from Flores."
Professor Cooper said the Centre for Ancient DNA would provide world-leading technology, providing Australian and international scientists with techniques currently considered impossible to extract and study DNA from specimens.
"This facility will put Australia on the international map very quickly," he said. "It will train a new generation of scientists and provide access to the genetic past of our environment."
Story Candy Gibson