A major step forward in bringing back the woolly mammoth has been taken by scientists at Harvard University who have inserted DNA from the extinct mammal into the genetic code of an elephant. Geneticists have studied DNA from mammoths which were preserved in Arctic permafrost looking for genes which separated them from elephants, such as hairiness and ear size. They then replicated the genes and spliced them into the genetic code of an elephant where they functioned normally. It is the first time that mammoth genes have been alive for more than 3,300 years - although so far it has only been done in the lab. George Church, professor of genetics at Harvard University, used a new technique which allows scientists to make precision edits to DNA, replacing sections of elephant DNA with the mammoth genes. "We prioritised genes associated with cold resistance including hairiness, ear size, subcutaneous fat and, especially," Prof Church told The Sunday Times. "We now have functioning elephant cells with mammoth DNA in them. We have not published it in a scientific journal because there is more work to do, but we plan to do so." Mammoths are closely related to Asian elephants but died out in the last Ice Age. The last of the species survived on Wrangel Island in the Arctic Ocean until about 3,300 years ago. It was these caracasses which provided the DNA used by the scientist at Harvard. There are at least three separate teams trying to reconstruct the whole mammoth genome and bring back the creature. In her new book, How To Clone a Mammoth, Beth Shapiro of the University of California, an expert on ancient DNA, said: "If we really want to bring mammoths back to life, then we're in luck, as far as DNA preservation goes. “Some mammoths lived in places where their bones and carcasses were buried in permafrost, like being stuck in a freezer for 30,000-plus years. "It's in pretty shoddy condition, so hard to piece together, but if we sort through these tiny pieces, finding where they fit along the elephant genome, then we can slowly build a lot of the mammoth genome." However some scientists believe that bringing back the mammoth would be unethical. Professor Alex Greenwood, an expert on ancient DNA, said: "We face the potential extinction of African and Asian elephants. Why bring back another elephantid from extinction when we cannot even keep the ones that are not extinct around? "What is the message? We can be as irresponsible with the environment as we want. Then we'll just clone things back? "Money would be better spent focusing on conserving what we do have than spending it on an animal that has been extinct for thousands of years." Source Reference to "Sexy Back" by JT in the title.