Scientists have brought back to life the blood of ancient mammoths and hope to use the technique to study extinct Australian marsupials including the giant kangaroo.
The researchers used DNA preserved in bones from Siberian specimens 25,000 to 43,000 years old to bring the primary component of mammoth blood back to life, says one of the team, Adelaide University's Professor Alan Cooper.
It meant they could measure how mammoths functioned as if they were still alive.
Principle 'simple'
"No one has done that before, to actually bring back a complex protein and test it to see how it works," Prof Cooper told AAP.
"The principle is fairly simple, you could certainly do it on a variety of other species or other proteins, and you are able to access all sorts of these extinct species.
"It is not going to do dinosaurs or anything in the million years region ... but we are also looking at a lot of the extinct Australian marsupials, the big giant kangaroos and all sorts of weird and wonderful things."
Climate makes a difference
In cold climates the range could be a couple of hundred thousand years back but Australia is so hot they would probably only be able to do it for animals that became extinct in the past 30,000 to 40,000 years.
Prof Cooper, who is director of the Australian Centre for Ancient DNA, says the team - led by Professor Kevin Campbell of the University of Manitoba in Canada - began work more than seven years ago.
"At the time, I thought what a great idea - but it is never going to work," Prof Cooper said.
But it did.
"We chose haemoglobin because we figured that normally in animals it is quite sensitive to temperature," he said.
DNA inserted into E.coli
The team converted the mammoth haemoglobin DNA sequences into RNA (Ribonucleic acid) and inserted them into modern-day E. coli bacteria, which then manufactured the authentic mammoth protein.
The scientists say the resulting haemoglobin molecules were no different than going back in time and taking a blood sample from a real mammoth.
Using modern physiological tests and chemical modelling they then discovered how the mammoth survived the extreme Arctic cold - with changes to the protein sequence allowed the mammoth's blood to deliver cells even at very low temperatures.
The research is to be published on Monday in the journal Nature Genetics.
