An extraordinary report was made public by a group of scientists from Japan. It is for the first time in human history that the tissue of a 16 year-old frozen mouse was successfully used in a cloning process.

The tissue was used to produce four healthy mice, spawning many theories about the countless possibilities brought by this bio-tech breakthrough. A similar scenario was used for the Jurassic Park movie, with prehistoric animals brought back to life, but at the time such a procedure was considered unrealistic. Now, many believe that it won’t be long until prehistoric mammals located in the arctic tundra will provide all the needed elements to bring back some of the animals we’ve lost during Earth’s evolution.

The study was presented in the journal Proceedings of the National Academy of Sciences and was conducted by Sayaka Wakayama of the Center for Developmental Biology in Kobe.

“It’s not the first time that dead animals have been resurrected,” said George E. Seidel Jr. of Colorado State University in Fort Collins, editor of the study. “But previously they were stored much colder than these temperatures and they were generally treated in a special way.” The focus will now be turned on the possibility of bringing back animals such as the woolly mammoth, a huge creature that weighed as much as 6 tons, which originated in Eurasia more than 250,000 years ago and disappeared by the end of the Pleistocene era about 10,000 B.C.

"It would be very difficult, but our work suggests that it is no longer science fiction," team leader Teruhiko Wakayama of the RIKEN Center for Developmental Biology in Kobe, Japan, said during an interview with New Scientist magazine.

The news immediately started many debates, as there are several scientists who believe that such experiments can only be taken so far, considering it impossible to clone extinct species. They say that there are no live cells available on the body and that whatever piece of genetic material might be found is very likely to be degraded and unusable. Still, the same nuclear transfer techniques could be used on extinct species. The study notes that "techniques could be used to 'resurrect' animals or maintain valuable genomic stocks from tissues frozen for prolonged periods without any cryopreservation."

Mr. Seidel explained that an attempt to reproduce a woolly mammoth is unlikely to happen over the next decade, as there are many aspects that need to be considered: the cells are expected to die once they are thawed out and also, at this point there are no live eggs – with the only possibility being to use an elephant egg to host the woolly mammoth clone. “It’s a long shot, but it’s evidence along the lines that that might be possible,” Seidel concluded during a telephone interview.

It is indeed a huge break-through which is expected to also lead to many others as the possibility of resurrecting some of the lost species represented up until recently only a distant dream for many scientists.