Mammoths, a close relative of Asian elephants, roamed four continents before being were driven to extinction around 5,000 years ago. He said: "Our aim is to produce a hybrid elephant-mammoth embryo".
There are also a number of ethical concerns needing to be addressed, such as ensuring the hybrids are accepted into elephant communities, as elephants are known to be social animals. "We're not there yet, but it could happen in a couple of years", added Prof Church, speaking at the American Association for the Advancement of Science annual meeting in Boston.
The project is still a long way off of creating a living mammophant, but birthing a hybrid animal could be achieved via an artificial womb, bypassing ethical concerns about experimenting on elephant surrogates and forcing them into hard pregnancies. The scientists only took genes that are not found in modern Asian elephants, such as the shaggy coat, big ears, and antifreeze blood.
If we've learned anything from sci-fi movies, it's that plans to bring animals back from extinction can sometimes go terribly, horribly wrong.
Since starting the ambitious project in 2015, the scientists have increased the number of "edits" where mammoth DNA has been spliced into the elephant genome from 15 to 45. This is because they help prevent tundra permafrost from melting and releasing huge amounts of the methane greenhouse gases trapped below into the atmosphere. "In the summer they knock down trees and help the grass grow". Genes and gene clusters responsible for key differences between mammoths and elephants have been identified, and a team at Harvard University has started inserting them into living elephant cells.
That sort of development is still in the works and may be for many years to come.
Previous research has suggested that reintroducing mammoths in Siberia could cause temperatures to drop by up to 20C. Mammoths can survive in cold environments inhospitable to humans, and Church believes the hybrids could flourish there as well. Nuclei from the reprogrammed cells would be placed into elephant egg cells whose own genetic material has been removed.
Experts then intend to grow the hybrid creature using an artificial womb. It would be unreasonable to put female reproduction at risk in an endangered species. There are experiments in the literature from the 1980s but there hasn't been much interest for a while.