University of Otago zoologist Prof Phil Seddon made the comments after Prof George Church said his team of Harvard University scientists was two years away from creating a hybrid embryo, in which woolly mammoth traits would be programmed into an Asian elephant.
Prof Church said the group would grow the hybrid animal in an artificial womb rather than using a surrogate.
Woolly mammoths became extinct about 4000 years ago because of human hunting and warming temperatures.
Prof Seddon said it was unrealistic to expect any hybrid form of mammoth to be introduced within two years.
``One obstacle to production of living hybrid elephants would relate to using an elephant surrogate, but the suggestion is to avoid this hurdle by growing a hybrid elephant in vitro - this seems a massive technical hurdle that has ethical implications at the very least.''
Prof Seddon said Prof Church's argument that creating a hybrid animal, which would not be a true mammoth, but instead a ``genetically modified elephant'', would help conservation efforts was ``not really defensible''.
``This won't seem to do much for elephant conservation - how will elephant populations benefit from having some GMO version around?
``There is not a strong justification for trying to re-create a lost ecosystem from 10,000 years ago, nor any certainty that this could even be done.''
The idea the animal could be released and help fight global warming by preventing the tundra from thawing was fraught with problems.
``Any elephant hybrid is not a lost species and has no former indigenous range. ``Also, the former range of the mammoth has changed in the last 10,000 years and is no longer habitat for mammoths, and anyway, no-one knows what the habitat requirements would be for a GMO elephant.''
The bottom line was there seemed to be ``an obsession with mammoths that leads some to propose solutions in search of problems''.
``Just because something might be technically feasible ... doesn't mean it is a good idea.
``I am yet to see any compelling case made that this type of high-tech project is worth the distraction from the real, tractable problems facing extant species and ecosystems.''
