“We have beaten the time barrier,” says evolutionary biologist Ludovic Orlando of the University of Copenhagen, who led the work with colleague Eske Willerslev. Noting that the oldest DNA sequenced before this came from a polar bear between 110,000 and 130,000 years old2, Orlando says: “All of a sudden, you have access to many more extinct species than you could have ever dreamed of sequencing before.”
Although Willerslev and Orlando say that it would theoretically be possible to resurrect the ancient horse by implanting a modern horse egg with the ancient DNA, they have no plans to do so. They say that it has been a formidable task just to assemble the genome from many small fragments of DNA. For now, they prefer to focus on further improving their techniques, before testing them on other samples.