Should We Bring Species Back From Extinction?

Yes!

If you had a chance to save a species from extinction, would you take it? I would—and I am.1

There are numerous arguments in favor of de-extinction science, but I want to focus on the most pressing one: conservation. Experts predict that the earth could soon lose at least 40 percent of its biodiversity. My colleagues and I often cite a stat from the Harvard biologist E.O. Wilson: that around 30,000 species are disappearing every year, or nearly three per hour. And yet we have the capacity not only to stop extinction but to reverse it. To save the planet’s biodiversity, de-extinction must become Conservation 2.0.2

My team and I at Colossal, a de-extinction company and lab, are establishing protocols, partnerships, and programs to create reproducible, affordable, and efficient processes to bring back marsupial, mammal, and avian species. To do this, we have built relationships with researchers with expertise in genomics, artificial intelligence, stem cell and assisted reproductive technologies, ex-utero development, animal wellness programs, and rewilding models. Together we are learning how to protect species from permanent extinction.3

In the future, our processes could be used to track threatened species in the wild, build a biobank of their cells, and then transport and store those cells. The procedures that we’re developing will allow scientists to turn the cells into animals using genomics, ex-utero gestation, genome editing, and trait engineering. From there, we can introduce these animals into the environment. This will not happen overnight, but we are making progress on every step.4

Until recently, conservation efforts have been our best approach to protecting biodiversity. And with some species, conservationists have been successful. They have raised awareness about species loss, developed captive breeding and release programs, and created species and habitat protections. They have stabilized the population of the American alligator, bald eagle, gray wolf, panda, and more. We should celebrate these victories, but we must also acknowledge that there are even more conservation failures.5

The current efforts of conservation organizations are not enough. In 2019, 70 academics, professionals, and researchers at the Luc Hoffmann Institute, a research body set up by the World Wildlife Foundation, concluded that a new generation of conservation techniques is needed to address the mounting challenges.6

De-extinction is that new generation of science that will prove to be the greatest ally of conservation. And it is already happening. In our efforts to de-extinct the woolly mammoth, we have brought together prominent conservation experts, committed funding to end a deadly elephant herpes virus, and supported assisted reproductive technologies for species outside of our immediate purview. The development of a de-extinction pipeline brings with it other scientific advancements that further help conservation. We believe conservation and de-extinction are inseparable.7

De-extinction is not at odds with conservationism; rather, it is turbocharging the field. When our efforts succeed, we will be able to rewild ecosystems as a way to help reverse climate change, combat invasive species, mitigate diseases, and bring back habitats. The woolly mammoth, for example, used to be vital in sustaining the Arctic steppe. In the past 40 years, the Arctic has warmed four times faster than the rest of the globe. Reintroducing woolly mammoths can help bring back a similar ecosystem, trapping more organic matter in the permafrost and thus reducing the release of greenhouse gases. We are providing the conservation world with a suite of tools and technologies that will allow us to move conversation from preservation to restoration.8

Standing idly by in the face of human-driven extinction is the wrong strategy. Why the urgency? When keystone species disappear, ecosystems may diminish or disappear too. Rapid climate change can also wipe out habitats. When that happens, bringing back a species becomes more challenging: The environment is not welcoming for the species to thrive.9

We must also contend with finite resources: time, capital, labor hours. It is essential to capture genomic diversity, biobank the results, and use healthy surrogates to maintain reproductive fitness. Healthy surrogates, for example, are missing from the rescue project for the northern white rhino, and scientists are exploring using reproductive technologies in related species instead. It will work, but it will take longer and require more resources.10

Finally, to de-extinct a species, we need DNA. And it is easiest and best to gather that DNA from a living species. The longer we wait, the harder it will be to get the genomic material needed to bring back species.11

We must take advantage of innovations. We cannot settle for an out-of-date philosophy of protecting what remains; we must begin to restore what’s been lost. Today, we’re doing that by developing processes to bring species back from extinction. My biggest worry is that we’re not doing it fast enough.12

Eriona Hysolli13

No!

De-extinction is not conservation. It does not heal the wounds of the present, and it is not the way to steward the future. In some ways, it’s an appealing idea: Who hasn’t dreamed of meeting a species from the past? Imagine watching a pterodactyl soar, a saber-toothed cat hunt, or a terror bird run. How cool would that be?14

But here’s the thing about species: They are the product of a particular time and place. Species coevolve and are entwined with their living and nonliving habitats—whether that’s the Cretaceous swamp, the mosaic Pleistocene steppe, or the flooded Sahara. The environment builds and sustains species—until it doesn’t. And when those habitats disappear, so do the species that relied on them.15

Over the last 4.5 billion years, countless species have come and gone. The habitats that made them are gone, too. Even now-extinct species that were with us a century ago would find today’s world a very different place. But biotechnology may soon allow us to bring look-alikes of long-vanished species into the present. Proponents of de-extinction argue that tinkering with the genomes of these chimeras can be done in service to the conservation of today’s imperiled species. Or that a particular resurrected species, such as the woolly mammoth, could serve as an ecosystem engineer to help re-create old habitats, increase carbon capture, and mitigate climate change. These are false promises.16

Not surprisingly, charismatic animals are the seductive marketing hook for de-extinction enthusiasts—think of the dodo, the Tasmanian tiger, or the passenger pigeon. But even if we could replicate such species and find a potentially suitable habitat to release one, 10, or 10,000 of them, we can’t bring back the accumulated millennia of their learned behaviors, diets, predators, or microbiomes that made these species what they were and allowed them to be part of a complex ecosystem.17

So beyond the “gee whiz” factor, what is the real purpose and benefit of de-extinction? What are its costs and consequences? And are we prepared for the myriad ethical and practical challenges posed by unleashing these living technologies from the laboratory?18

The answer to this last question is a resounding “no.” The technology is far ahead of any regulatory framework that could provide the guardrails to minimize unintended consequences. Our smattering of federal and state laws on this are targeted to address specific present-day concerns, such as preventing the import of agricultural pests or the trade in body parts like ivory tusks or pangolin scales. They do not provide a structure for managing the introduction of untested simulations of extinct wildlife. And given our political gridlock, we can’t count on lawmakers to take up these issues in a timely way, let alone find consensus. That leaves us relying on the integrity of individual scientists and, perhaps more important, the businesses that fund de-extinction work.19

Legal questions abound: Will we classify these new “old” species as “endangered” and try to protect them, or are they destined to supply us with food and curiosities? Will they be owned by the companies that created them, and who will benefit from their revival? And if the goal is “reintroduction” to some place, how do we decide which place and why? Who is responsible for whatever impacts emerge from their introduction? And the impacts would be dramatic: Witness the controversies over wild horses in North America’s Great Basin, a prime example of a species returned to a place it evolved in after an absence of 10,000 years.20

Even more fundamental are an array of ethical questions. Foundational to our responsibility as scientists and citizens is the ethical treatment of other beings. What do we owe to those individuals we conjure up to live without the ecological bonds that nurtured them? And what do we owe to existing life in the ecosystems into which we would introduce them? Extinct species are pieces that do not fit into the puzzle of life today.21

There is a reason we don’t shuffle species around the planet: We know that such introductions often result in cascading ecological consequences. Conservation biologists do not advocate transporting penguins to the Arctic or polar bears to Antarctica. We don’t hear calls for introducing imperiled tigers to the Amazon. Why? Because we know from long experience that even the best-intentioned introductions can disrupt delicately balanced ecosystems. What hubris makes us think we would do any better introducing the woolly mammoth where it has not walked for more than 10,000 years, in a place that in no way resembles what it was at that time?22

We are woefully unprepared—legally, morally, and scientifically—to “play God” by resurrecting extinct species. Although the “gee whiz” factor (and the financial incentives) might push us in that direction, the better use of society’s resources would be to work on saving what we still have.23

Elizabeth A. Hadly and Deborah A. Sivas24