Scientists think they could 'de-extinct' the Christmas Island rat. But ...

"A lot of them have evolved to work with other ones and when one gene changes, another gene changes at the same time."In other words, the unrecoverable parts of the Christmas Island rat genome could make it so that the rodents have immune systems that aren't properly adapted to their habitats or are unable to process smells the way they were when the species was alive.These issues could have significant ethical implications for the resurrected animals, said Ross MacPhee, a senior curator at the American Museum of Natural History and a co-author of the study."The science of de-extinction is fantastically interesting, but the proposition that we've lost species and so we'll just bring them back is not thinking it through with respect to animal welfare," he said.Rather than reviving long-extinct animals such as woolly mammoths, MacPhee said CRISPR could instead be a valuable tool to make genetic tweaks to vulnerable living species in order to help them survive better in the wild.