The idea is not as crazy as it sounds. Already, scientists have been able to sequence much of the genome of the extinct Siberian mammoth. Previously, only tiny fragments of DNA had been extracted from woolly mammoths that were frozen in Siberia tens of thousands of years ago. Webb Miller and Stephan C. Schuster of Pennsylvania State Univ ersity did the impossible: extract 3 billion base pairs of DNA from the frozen carcasses of the mammoths. Previously, the record for sequencing the DNA of an extinct species was only 13 million base pairs, less than 1 percent of the animal’s genome. (This breakthrough was made possible by a new sequencing machine, called the high-throughput sequencing device, that allows one to scan thousands of genes at once, rather than individually.) Another trick was knowing where to look for ancient DNA. Miller and Schuster found that the hair follicle of the woolly mammoth, not the body itself, contained the best DNA.
The idea of resurrecting an extinct animal may now be biologically possible. “A year ago, I would have said this was science fiction,” Schuster said. But now, with so much of the mammoth genome sequenced, this is no longer out of the question. He even sketched how this might be done. He estimated that perhaps only 400,000 changes in the DNA of an Asian elephant could create an animal that had all the essential features of a woolly mammoth. It might be possible to genetically alter the elephant’s DNA to accommodate these changes, insert this into the nucleus of an elephant egg, and then implant the egg into a female elephant.