If you think bringing extinct species, such as the moa, back to life is simply science fiction fantasy, think again.
Some scientists such as University of Otago zoologist Philip Seddon, say such questions are moving from the realm of science fiction into science fact.
Prof Seddon has co-authored an article on de-extinction in the ecological journal, Trends in Ecology and Evolution.
The article has already sparked considerable international attention, including a recent lengthy article on ''de-extinction'' in the New York Times, which refers to his research.
He says technological advances have raised the controversial prospect of resurrecting extinct species.
And Labour MP Trevor Mallard, perhaps inspired by this growing international interest, has recently spoken about his vision of 1.8m moa again roaming a forest park, in a ''snapshot of New Zealand as it once was before the arrival of the humans''.
Prof Seddon heads an international team developing policy on ''de-extinction'' for the United Nations-linked International Union for the Conservation of Nature (IUCN).
''I've assembled a team of 10 international conservation experts and we've started work. It feels like both a huge honour and a very great responsibility.''
He is well aware of the growing international interest in bringing extinct species back to life, and re-establishing them in a protected environment.
''The potential of de-extinction fires the imagination of everyone, scientists and the public alike,'' he says.
''How cool would it be to see a woolly mammoth?''Although some people had been critical of bringing back moa, the possibility of ''de-extincting'' some extinct animals was ''very real''.
And, he points out, ''it's already happened'' in the case of the ''de-extincting''of a European mountain goat.
Conservation authorities around the world were now taking this concept ''very seriously''.
Some people are horrified at talk of ''de-extinction', partly because they fear that if extinct species can be brought back to life, this will distract resources and attention from the more urgent task of saving endangered species from the imminent risk of extinction.
But there could be a positive side to some carefully-considered ''de-extinctions'', he says.
''The possibility of bringing back a species must raise questions about whether there is suitable habitat and could even be a major incentive for habitat restorations.
''And good habitat for mammoths, or moa or huia, will also be good habitat for a multitude of other native species.''
Overseas researchers recently cloned an extinct type of European mountain goat from tissue, using an egg cell of a domestic goat, which also acted as a surrogate mother. However, the kid died within a few minutes of birth.
Prof Seddon argues de-extinction ought to be more than a technical exercise.
If you want to resurrect a species, ''the idea is not to create something that's a curiosity in a zoo''.
It should be for some ecological gain- putting a species back into a suitable habitat to do the kind of things it used to do.
Teams of South Korean and Russian scientists are already working to reconstruct the DNA of Siberian mammoths, to possibly try to bring them back from extinction. And New Zealand has developed internationally recognised skills in reintroducing threatened animals, such as birds we have protected on offshore islands.
The New Zealand public will need to think ''very carefully'' about what it wants.
Bringing back the huia, a small wattle bird which was last confirmed seen in 1907, and a small species of moa are among the possibilities.
They could live in protected areas in national parks if New Zealanders wanted them to make a comeback, he says.
Born to New Zealand parents, in Newcastle-upon-Tyne, England, Prof Seddon returned to New Zealand at the age of 3, living first in Auckland for 10 years, then in Wellington.
He later moved to Dunedin, where he gained an MSc (Hons) degree in zoology and then a PhD at Otago University.
''I have always been interested in animals and animal behaviour, and was an early devourer of TV wildlife documentaries.
''I started out looking at the behaviour of penguins, the yellow-eyed penguin in New Zealand and then the African penguin in South Africa and Namibia.
''Because both these species were threatened and in decline, it sparked my interest in conservation biology, the management and protection of endangered species.''
When Prof Seddon is not at university, family is a ''major part'' of his life.
And he and his wife, fellow Otago academic Yolanda van Heezik, and their two boys (10) and (17) enjoy outdoor activities together, including ''tramping, snorkelling, surfing, and snowboarding''. He also holds a black belt in karate.
The New Zealand public ''needs a say in how we manage our cultural heritage'', he says.
Ultimately, the public should decide if de-extinction is a positive move, or if scarce conservation funding can be better spent saving what we still have.
Snapshot
Name: Phil Seddon (51)
Occupation: University of Otago zoologist
Qualifications: PhD in zoology
Where did you train: University of Otago
Work history: Cape Town University, and Saudi Arabia, working in protected areas, and on species restoration projects
Proudest: Member of international group writing guidelines for international species reintroductions
THE CHALLENGE:REINTRODUCING EXTINCT ANIMALS
What is it about? It is now technically possible to resurrect extinct species, but should we, and if we do, which ones?
Why is it important? The possibility of species de-extinction raises many challenges to the conservation of existing species. What if extinction is not forever?
Most interesting aspect? Appreciating the implications of new technology and ensuring it is applied for conservation benefits.
How the science works: DNA is obtained from bones or other remnants of extinct species, the DNA reconstructed, sometimes using related species, and a host animal helps bring the lost species back to life.
Reintroduction biology: Involves moving threatened species - for instance, plants or animals from a captive collection or wild population - back into suitable habitat in areas where they used to be.
