Colossal Bioscience—the same company that claimed to “de-extinct” the dire wolf and touted a “woolly mouse” bearing mammoth genes—announced the development of an “artificial egg” that it says is a step toward “resurrecting” extinct birds including New Zealand’s giant moa and Mauritius’ famous dodo.Many scientists disagree with the entire notion of “de-extinction.”“Nothing will ever bring back a mammoth; nothing will ever bring back a dodo,” says Victoria Herridge, an evolutionary biologist at Sheffield University in the U.K. “Extinction really is forever.”On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.But Colossal’s “artificial egg” technology is intriguing. In past work in mammals, scientists have proposed using closely related, still existent species to impregnate with lab-created embryos carrying the genetic material of an extinct species. That isn’t possible for birds, however. Instead, something replicating the environment inside an egg is needed, and while scientists have tried to develop egg-free incubation systems, these have had minimal success.According to a Colossal Biosciences press release, its scientists developed “a semi-permeable silicone-based membrane housed inside a rigid hexagonal support cup,”—an artificial environment designed to keep moisture inside the embryo while delivering oxygen and keeping out contaminants.Colossal says the system will work for any size of egg, whether it hatches a hummingbird or a moa, and that it had successfully hatched 26 chickens. But the release offered no detail on how many embryos were originally made or how many were loaded into the facility, how long the chicks survived, or anything that speaks to their health. Colossal Biosciences did not respond to a request for comment.The company also says that it has “not released a peer-reviewed paper or publicly available dataset accompanying the artificial egg results. Independent scientists have not yet evaluated the methodology.”Previously, scientists have come up with artificial casings that can enable chicken or quail embryos implanted inside to grow into full-fledged chicks, the hatching rate for those systems remains low, making them inefficient and unpredictable, says Mike McGrew, a professor specializing in embryology at the University of Edinburgh. “If Colossal’s hatch rate is higher, then that would be useful,” he says, adding that the tech would be particularly helpful to conservation efforts if it can be expanded to species with larger eggs, such as emus and ducks.Nic Rawlence, an evolutionary geneticist at the University of Otago, New Zealand, told Nature that he could see the artificial eggs potentially supporting breeding of the flightless kākāpō (Strigops habroptilus) parrot, which is endangered on New Zealand. “That’s what Colossal should be focusing on rather than bringing in the whole de-extinction angle,” he said.Some experts are more skeptical of the practicality of Colossal’s system. Chris Elphick, an ornithologist at the University of Connecticut, says that as it stands, Colossal’s technique seems to involve pouring the contents of a natural chicken egg into an artificial shell. “You could just leave the embryo in the egg that it’s already in for any existing species,” he says.Certainly, many existing captive breeding programs, such as those in place for the critically endangered ‘akikiki in Hawaii, are leading to growing population numbers without artificial eggs, says Michael Parr, president of the American Bird Conservancy. Using artificial eggs may be a more expensive way of reaching the same results.“A lot of these species, it's not so much the breeding that’s not working, it’s what happens when you reintroduce them to the wild, and what were the conditions that caused them to become rare or near extinction in the first place,” he says.Elphick says that the same hurdles would exist should technology ever actually make possible the de-extinction of moas. “Apart from the technical issues, there’s the practical issues,” he says. “Where you going to put them? (Humans) destroyed their habitat, there’s a reason they're extinct.’Herridge agrees that the priority should be conservation, arguing against “de-extinction” as a way of framing Colossal’s projects. “They’re synthetic biology experiments at the moment,” she says. “They’re actually about creating novel organisms, something completely new.”The company says that they might be able to match specific traits associated with a lost species. “We want to create functional versions of extinct species,” Beth Shapiro, Colossal’s chief science officer, told Scientific American when the company announced three “dire wolf pups,” which are actually gray wolves sporting 20 genetic edits. “We don’t have to have something that is 100 percent genetically identical.” The company also announced a program targeting the extirpated bluebuck antelope.Herridge argues that scientists don’t know enough about the ecology of lost species to replicate even a single aspect of an animal. And the work allows us to dream of mammoth herds, rather than wrestle with the challenges of elephant conservation on a crowded, warming planet, she adds.“It doesn’t deal with any of the underlying problems that are currently facing our wild places and biodiversity today,” she says.It’s Time to Stand Up for ScienceIf you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. 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