Of course, that's not the only obstacle. The mammoth nuclei will have to be implanted into an elephant's egg cell, creating an embryo with mammoth DNA which will then in turn have to be implanted into an elephant's uterus. Frozen cloning of any sort is only about 30% successful, and though genetically elephants and mammoths are very similar, there's no telling how difficult it will be to induce an elephant to give birth to a mammoth. But Iritani hopes to overcome the remaining obstacles within five or six years, after which they'll hopefully have a new mammoth to study. The team wants to use the cloned mammoth to figure out the precise reason for the extinction of the species--at the moment, there's debate on the subject, with some arguing for climate change (i.e. an Ice Age) and some arguing for hunting to extinction by, well, us.