Beth Shapiro, chief scientist for the mammoth de-extinction effort: “It’s the last chance for many species on the verge of disappearing.”

De-extincting species is no longer a fantasy. After decades of research by academic institutions, a US company valued at around €10 billion has managed to de-extinct an animal, although it hasn't convinced the scientific community. This year, Colossal has announced the creation of woolly mice with genes rescued from the mammoth, giant wolves with genes extinct for more than 10,000 years, and advances in assisted reproduction for birds to resurrect the dodo, the flightless bird that disappeared in the 17th century due to humans and their introduced animals. The next goal is to recover the woolly mammoth using the Asian elephant as a base.

Colossal's chief scientist is Beth Shapiro, a 49-year-old American zoologist. After starting her career as a journalist and later becoming a leading researcher in ancient DNA in academia, she has headed the various research teams working to de-extinct the aforementioned animals, as well as the Tasmanian tiger and the New Zealand moa .

For Shapiro, the giant wolves embody the first successful de-extinction in history. The three specimens were created from cells of modern gray wolves into which 20 genetic changes characteristic of the extinct Canis dirus were introduced. For their detractors, these animals are nothing more than gray wolves modified to be more robust, larger, and whiter; they resemble their extinct relatives, but they are not the same thing . The only way to resurrect an extinct species, many experts point out, would be by cloning animals from their entire genome, which is impossible. The Pyrenean ibex has the dubious honor of representing the only partial success in this field of cloning: the only pup died 10 minutes after birth, more than 20 years ago.

De-extinction, as understood by Colossal, is different, but it also involves numerous scientific challenges that have yet to be overcome: mass gene editing, cloning, and, above all, using elephants to gestate the offspring for 22 months without, as Shapiro acknowledges, anyone knowing if everything has worked until they are born.

The idea is that all this science will help conserve many living species that are on the verge of extinction. Colossal's founders are the charismatic Harvard geneticist George Church and entrepreneur Ben Lamm, who argue that their creatures can restore ecosystems degraded by climate change and human pressure.

Since its creation in 2021, the company has raised hundreds of millions of dollars from fortunes such as Paris Hilton, Peter Jackson, and Thomas Tull, one of the creators of Jurassic World.

The organization plans to raise its mammoths in Alaska and its dodos in Mauritius. The giant wolves remain healthy a year after being born in a secret-location reserve in the United States. Artificial intelligence and drones will be a key surveillance tool to prevent these animals from escaping, explains Shapiro and three other scientists from Colossal in a recently published study.

Many conservationists question this project, given that living species can still be preserved. They also argue that researching pigeon eggs is not the same as researching elephants. From the scientific community, leading geneticists point out that none of the genomes of extinct species that we have are complete, and that their natural behavior and habitat have also disappeared forever, so we cannot speak of de-extinction . Others see potential undeclared industrial applications, or even a pastime for jaded billionaires.

In a key decision, the International Union for Conservation of Nature has just rejected a moratorium on synthetic biology projects that modify the genome of wild species , a near-green light for Colossal's projects.

Shapiro has been the scientific director of Colossal since March of last year, having moved there from her paleogenomics lab at the University of California , Santa Cruz. Despite the controversy, she remains a respected scientist in her field and publishes top-level studies, such as the recent genetic rescue of bacteria that lived in mammoths more than a million years ago . The scientist answers EL PAÍS's questions via videoconference from her home in California.

Question: What did you feel the first time you saw the giant wolves?

Answer: I was terrified it wouldn't work. In this case, we didn't use a gene from giant wolves because it's associated with blindness and deafness. We used genes for white fur, characteristic of gray wolves. My first question when I saw them was whether they were white. And I thought: damn, we did it, it works! Now we're seeing that the other changes—larger size, more muscle, very dense fur—have also occurred. It's amazing to be at the forefront of developing these tools that can help prevent other species from going extinct.

Q. How similar are these wolves to animals that lived 10,000 years ago?

R. Giant wolves lived in habitats during ice ages and interglacial periods, which we humans have completely altered. But they were very adaptable animals, and I'm sure the place where we're raising them now is similar to where they lived at some point. I don't think we'll learn much about their behavior because they've been raised by caretakers. We have two males and one female. We haven't let them breed yet, but our idea is that in the future there will be groups of about six individuals, and that at some point they will live in the wild. As they become more feral, we'll probably see how their larger size, muscles, and other physical characteristics translate into special behaviors, for example, when hunting their prey.

Q. And the next target is the woolly mammoth?

R. Yes. Our mammoth team is making great progress. We're focusing on woolliness and cold adaptation. Elephants have far fewer hair follicles, so we're exploring how to increase their number and make them produce longer, more distinctive hair. We're also identifying genetic variants related to other mammoth characteristics: longer tusks and shorter ears and tails. The genomic engineering team is developing a new tool, multiplex, to make hundreds of genetic changes in a single elephant cell at once. With dire wolves, we only had to modify 20 genes, but this time we need to change hundreds.

Q. What do you mean?

R. You and I have about three million differences in our genomes, but we are both equally human . If I can figure out which changes are responsible for each characteristic we are interested in recovering, the goal will be to make the fewest possible changes. We are working with an elephant genome, and every change carries an additional risk. It's not about reproducing the entire genome of a mammoth, but about introducing key characteristics of mammoths into current species.

Q. And will that first mammoth be born to an Asian elephant?

R. That's the plan, yes. At the same time, we're about to announce the creation of reprogrammed elephant stem cells, which could help us develop sperm and eggs so we don't have to extract them from live animals. Another team is working on cross-species cloning techniques to gain access to embryonic stem cells, and we're also refining techniques for extracting eggs from elephants, which have been very underdeveloped. We face a lot of scientific challenges, and we're tackling them all at once to make as much progress as possible.

Q. When do you expect the first animal to be born?

R. When the company was founded, Church and Lamm said 2028; and our genomic engineering team is on track to achieve that. But elephants have a very long gestation period, 22 months. This means we have to know everything about assisted reproduction in elephants before the end of 2026. I believe it's possible, but we don't want to take any risks. I think we're on the right track to de-extinct the mammoth in three years, but there's a lot of work to be done.

Q. Why do they specifically want to de-extinct these five animals?

R. Many environments are changing at a rate that natural selection cannot keep up with . In an ideal world, we would stop expanding and give species the chance they deserve. But it's too late for that. The human footprint is too large, so we need new tools; and this includes bringing back the interaction between extinct species and ecosystems, allowing them to become more resilient. Imagine if we could modify the DNA of the Hawaiian honeycreeper [a group of birds on the brink of extinction] to make it resistant to malaria, a disease that humans introduced through mosquitoes. Something similar happens with the black-footed ferret or the vaquita porpoise . That would allow them to continue living in their environment despite human activity. This selection of species—two placental mammals, a marsupial mammal, and a pair of birds—means that we can achieve tools applicable across the entire tree of animal life, in order to help species avoid extinction. In many cases, it is the last chance for many species on the verge of disappearing. We urgently need these tools to have a future in which biodiversity and human presence are not incompatible.

Q. What benefit would elephants modified with mammoth genes provide?

R. In the permafrost [the permanently frozen layer of soil in the regions surrounding the poles], they spread seeds and nutrients, aerate the soil, change the vegetation, and strengthen the ecosystem. In winter, when these animals search for food, they remove the snow, exposing patches of soil. In spring, different plants will grow in these areas, forming a mosaic where other plant species can thrive. Mammoths were the engineers of their ecosystems, just as elephants are today in theirs.

Q : What if something goes wrong, for example, if they escape?

R. I think we are capable of assessing risks. Since our existence, humans have influenced the evolutionary future of most of the species we have encountered. We have transformed the gray wolf into Chihuahuas and Great Danes; we have turned teosinte into all varieties of sweet corn. Now we decide where, how, and how many threatened species we allow to survive, and we call it conservation. It is important, of course. But we need to improve. Some people say that these new tools are dangerous, but they forget that not applying them will have consequences in a world where the extinction rate is the highest in all of history and the fossil record.

Q. There are leading experts in ancient DNA who deny that these are de-extinct species. What is your opinion?

R. We humans create the definitions of species, and then we disagree with them, but do you know who doesn't care about any of this? Ecosystems, which are missing the function these animals can play. Whether people want to call them giant wolves or wolves 2.0 doesn't really matter. For us, they will be wolves if they behave like wolves and fulfill their role.

Q. And what do you think of conservationists who say: first, let's save the current species?

R. It's not a dilemma. We can do both. We just want to create a new way to help certain species survive humans. We need more tools, not fewer.

Q. How will you make all this scientific effort profitable?

R. We're developing many interesting technologies that we'll donate for free to conservation. But we're also going to patent many of these advances, and I think most of the profit will come from selling them in the broader healthcare field. We have a team of 17 people developing an artificial womb to avoid using elephants, but it's obvious that such an advance will also have an impact on human reproduction and health. There are many ways to make money from all of this.

Q. Could this technology be applied to de-extinct human species, such as Neanderthals ?

R. That's the ethical line I don't want to cross. When you work with humans, there's one unique and fundamental requirement: informed consent from the patients. They must understand what the experiment involves and give their approval. We, Neanderthals, and Denisovans are all equally human, and I can't think of how to get their consent to bring them back to life. This question is fascinating from a theoretical point of view, but it's not something we're going to do.