First revival of extinct species attempted
As part of the aptly named "Lazarus Project", scientists are attempting to revive the extinct gastric-brooding frog, R. silus.
The frogs inhabited creeks in a fairly small area of tropical forest in Queensland, Australia. Discovered in 1973, the species had already disappeared by the mid-1980s. Habitat degradation, pollution and disease are thought to have contributed to their extinction.
A few specimens of the gastric-brooding frogs are preserved in museums, which led scientists to consider the possibility of reviving the species.
Scientists have used cloning technology to implant a "dead" cell nucleus into an egg from a distantly related frog species, the great barred frog.
During repeated experiments over five years, the scientists have managed to get some of the eggs to spontaneously divide and grow into early embryos.
Whilst none of the embryos have survived more than a few days, genetic tests have confirmed that the dividing cells contain genetic material from the extinct frog.
Project leader Mike Archer said: "We're all very optimistic that we're going to get this frog hopping, glad to be back in the world."