Reviving extinct species: Can we? Should we?
Fourth graders inspect a model of a dodo bird at the American Museum of Natural History in New York, in 2016. Researchers at Colossal Biosciences, a biotechnology company, have hatched a plan to revive the extinct species.
Mary Altaffer/AP/File
The 1993 film “Jurassic Park” amazed moviegoers with a glimpse into a world that no longer exists – when dinosaurs roamed the Earth. The idea of being able to see and interact with these long-gone creatures was awe-inspiring, but also scary when the electric fences lost power.
Today some of the same ethical questions raised by that fictional story – about our relationship with the natural world and the consequences of “playing God” – are gaining real-world relevance due to advances in bioengineering.
De-extinction is the idea of bringing extinct species back to life. Advanced genetic engineering techniques are opening the door to doing just that, some scientists say. Efforts now underway to bring back species like the woolly mammoth and the dodo are stirring a blend of wonder, investment, curiosity, and criticism.
Why We Wrote This
Righting a wrong? Or playing God? Emerging efforts to revive species that have been hunted to extinction are raising questions about the promise – and ethics – of bioengineering.
However it plays out, some bioethicists see a larger lesson about the interconnections between political, economic, and ecological concerns.
“What biotechnology ought to do is to teach us to pay attention to interdependency and the interrelationship of all forms of life on the planet,” says Bruce Jennings, a senior fellow at the Center for Humans and Nature. If ecosystems and animals “can flourish and can adapt to the changing weather, that’s beneficial for human beings. If we think about ourselves only, we’re not thinking about ourselves well.”
What is de-extinction?
Over time, scientists have been exploring several approaches to reviving extinct species. “Backbreeding” is a form of selective breeding, aiming to revive specific ancestral characteristics. Cloning is another option, growing a new embryo (within a species closely related to the extinct one) using a preserved cell nucleus. The recent focus has shifted to a third option: extracting DNA from the remains of an extinct species to create a genetic blueprint that can be inserted into the DNA of a living organism.
All of these methods have challenges that cause some scientists to question whether true de-extinction is even possible.
The company at the forefront of new efforts in this field is Colossal Biosciences, based in Austin, Texas. Founded in 2021, the company first made headlines for its ambition to de-extinct the woolly mammoth within a few years. Most recently, it announced a new project aimed at bringing back the dodo, a bird endemic to the island of Mauritius in the Indian Ocean, that was famously hunted to extinction by humans in the 17th century.
By using gene editing to influence the offspring of modern-day Asian elephants, Colossal expects to produce not a true woolly mammoth but a hybrid species that possesses key woolly mammoth traits.
“What we’re looking at are the core genes that make a mammoth a mammoth and engineering those into existing genes in the Asian elephant genome,” says Beth Shapiro, lead paleogeneticist at Colossal.
Will it work?
Colossal is optimistic. “We haven’t set any timeline on the dodo because applying some of the technologies from our work in mammalian cells to avian just hasn’t been done before,” says CEO and founder Ben Lamm. “We have set a goal for 2028 for our first mammoth calves, and we’re making steady progress on it. There’s no reason to think that we won’t hit those timelines now.”
To skeptics, this won’t really be de-extinction.
“I have a lot of respect for people like Beth Shapiro. She’s done amazing work,” says Corey Bradshaw, professor of global ecology at Flinders University of Adelaide, Australia. “But … I don’t think it will ever be achieved technologically speaking. You have to be able to get every part of the genomic sequence to produce a healthy organism, and you can’t gain every single component of an entire genome without making a mistake in the translation.”
Dr. Bradshaw adds that the population of a revived species won’t be able to expand successfully without adequate genetic diversity, for the same reason that inbreeding carries deleterious effects on offspring in existing species.
Scientists also question whether a revived species will be able to rebuild its population without the former social culture (with their own species) and ecosystems they once relied on.
What values are behind the efforts?
At a basic level, some proponents point to the sense of wonder and appreciation of nature that could grow from the return of a creature like the dodo.
Some see a moral obligation, too: When possible, why not try to revive a species if humans played a key role in its extinction?
Backers also say de-extinction holds a range of potential benefits from expanding biodiversity to protecting or reviving certain ecosystems, which helps humans too.
“Unfortunately, biodiversity loss is a major thing that [humans] are contributing to,” says Colossal’s Mr. Lamm. “What we know is that modern conservation works. It just doesn’t work as fast as humans change the environment or eradicate the species or pollute the environment. And so for us, one of the core values is that we want to ensure that all the technologies that we develop have an application to humans. And giving those technologies to the world to help the biodiversity crisis, we also are looking to bring awareness through these high-profile projects to these issues.”
He says his firm aims to collaborate with stakeholders such as local governments and Indigenous people – including providing its technologies to conservation groups for species preservation, “as well as apply some of those technologies to human health care. That is our goal and our vision.”
Supporters of de-extinction say their efforts can work in tandem with, rather than detract from, ongoing conservation efforts.
What are the objections?
Some say money and scientific muscle could be better used for more traditional efforts to preserve today’s biodiversity. A related concern is that commercial interests could dominate decision-making, amid inadequate public oversight. That could add to the risk of unintended consequences.
In a survey published in 2019 by the Journal of Responsible Innovation, experts generally “indicated de-extinction was more likely to induce hazards, not benefits,” according to a summary of the results.
Dr. Bradshaw, the ecologist in Australia, notes the bigger context: “We’re losing species faster than we have at any point in human history and even geological time,” so the paramount focus should be on saving the biodiversity that currently exists.
“I’m not saying that it’s obviously unethical, case closed” to pursue de-extinction, says Mr. Jennings, who teaches at Vanderbilt University in Nashville, Tennessee. “But I do think that part of ethics is not just the logic of your argument and your conclusions, but it’s also the way you carefully define the problem and the goals. I don’t think the problem of the North [where mammoths may have once helped maintain permafrost] is the absence of mammals. I think the problem of the North is the warming [climate].”
That view echoes other experts who don’t necessarily rule out de-extinction but also see its justifiable use as limited.
In the end, what unites many on both sides is a respect for nature and the goal of stemming a massive decline in biodiversity that is currently underway. Where the critics of de-extinction urge using precious dollars to preserve existing ecosystems, proponents say the emerging technologies may play a positive role alongside those other efforts.