The scientists who want to bring back mammoths now hope to revive the marsupial carnivore thylacine
The thylacine has long been an icon of human-caused extinction. In the 1800s and early 1900s, European colonizers in Tasmania wrongly blamed the dog-sized, tiger-striped, carnivorous marsupial for killing their sheep and chickens. The settlers slaughtered thylacines by the thousands, exchanging the animals’ scalps for a government bounty. The last known thylacine spent its days pacing a zoo cage in Hobart, Tasmania, and died of neglect in 1936.
Colossal Biosciences, co-founded by Harvard University geneticist George Church and tech entrepreneur Ben Lamm, is working with the University of Melbourne’s Andrew Pask, who has already sequenced most of the thylacine genome. The thylacine is the perfect candidate for de-extinction, Pask says, because it died out relatively recently, good-quality DNA is available, and its prey and parts of its natural habitat still exist.
To resurrect the woolly mammoth, Colossal’s researchers plan to introduce mammoth genes into the genome of the Asian elephant, its closest living relative. They will then try to create an embryo carrying that modified DNA that could gestate in an African elephant “surrogate” or an artificial uterus. The resulting creature would not be a mammoth per se but rather a cold-adapted “Artic elephant” with small ears, shaggy hair, a domed forehead and curved tusks, Lamm says.
Next the researchers will compare the genome of the thylacine to that of one of its closest living relatives: the fat-tailed dunnart, a mouse-sized marsupial that is relatively abundant and copes well in captivity. Using CRISPR gene-editing technology, the scientists will engineer the dunnart’s genome to more closely resemble the thylacine’s.
Collectively, these new marsupial reproductive technologies could become crucial tools for the conservation of extant species such as koalas or numbats, Pask says. “There is absolutely no way I would have the millions that I have now for marsupial conservation if I [wasn’t] trying to bring the Tasmanian tiger back,” he says.