Few realities of scientific advancement have excited our novelistic minds as much as the possibility of de-extinctating species . The option of bringing back to our present-day world the grandeur and spectacle of animals whose impressive fossils in museums give us goosebumps has been a dream many of us have had since childhood.

So much so that writers have exploited this idea for decades. Subsequently, cinema has incorporated them into scripts that, although somewhat childish, contain a healthy dose of fable and are imbued with lucrative drama, keeping us glued to the screen, contemplating the spectacular nature of these colossi brought back to life.

But is it really feasible to do this? And more importantly, should we do everything we could ?

The problems of de-extinction could be articulated on three levels: the laboratory, nature, and our consciences.

The problems of de-extinction begin in the laboratory

Although biotechnological protocols allow us to do quite spectacular things in genetic engineering, the starting point remains a difficult problem to overcome.

While it’s true that DNA preserved in the skeletal remains of extinct animals can be extracted without too much difficulty, it’s very difficult to find complete genomes. This means we don’t have all the information on how to biologically engineer that animal: the “instruction book” is often missing many pages, if not entire chapters.

The easiest solution is to “fill in the gaps” with DNA from living animals for which we do have complete genetic information. It’s clear, then, that we’re cheating. The new animal isn’t what it was: it’s a substitute. We can’t establish the consequences of its existence a priori, since it’s neither the extinct nor the living animal, but a new one.

Another option is the one recently implemented by Colossal Biosciences. With a lavish media hype, it has supposedly “resurrected” the dire wolf ( Aenocyon dirus ), extinct in the Americas some 10,000 years ago. But this claim is not true. In reality, they didn’t start from the DNA of the dire wolf (also known as this species that inspired the direwolf of House Stark in Game of Thrones ). What they did was edit the DNA of a modern gray wolf ( Canis lupus ) using the CRISPR-Cas9 system.

This astonishing technique allows specific DNA sequences to be modified in a targeted manner, at will, just as if they were a Word document. The system, which earned scientists Emmanuelle Charpentier and Jennifer Doudna the 2020 Nobel Prize in Chemistry , designs a guide RNA that locates and attaches itself to a specific area of ​​DNA that interests us for whatever reason. This marks the location where the Cas9 protein (a kind of molecular scissors) must cut both strands of DNA. When the cell activates its own system to repair the “broken” DNA, we take the opportunity to introduce the “new text” with the genetic modifications that suit us.

Thus, the genetic “letters” and “words” of the gray wolf are voluntarily altered, allowing it to do such spectacular things as, where it used to say “big teeth,” now spell “enormous teeth.” Similarly, the shape of its skull, its size, and its coat, among other characteristics, have been modified.

But beware! The result isn’t giant wolves. The three beautiful pups are, in fact, “tuned” gray wolves. Nevertheless, the result is still spectacular, and the technique is astonishing.

We can de-extinct species but not environments.

Exceptionally, it is possible to access the complete genome of an extinct species. This is possible when low temperatures have preserved the tissues (skeletal and soft tissue) of some extinct species. In fact, woolly mammoth specimens from 52,000 years ago have been found in the Siberian permafrost , as “fresh” as the steaks in your freezer.

In this case, its intact nuclear DNA could be replaced by that of the nucleus of an elephant zygote (something similar to what we biologists do in assisted fertilization laboratories) and the early embryo implanted in an elephant uterus. Except for the fact that the elephant would have to be immunosuppressed so that it would not reject the embryo due to histocompatibility problems , the pregnancy could be carried to term. However, a certain minimum number of individuals would be necessary for the population to overcome the problems of inbreeding depression, have the capacity to adapt, and be viable as a biological species .

But on the other hand, what about the ecological niche this species occupied? Does it still exist today? Consider that, often, the cause of extinction lies precisely in the change in the environmental conditions where these extinct species thrived.

If we resurrect a species, we would condemn it to live in a urn that recreated its lost natural conditions. Even worse would be if its niche were occupied by another species, creating an artificial and unnecessary struggle that could lead to the paradox of de-extinguishing the past to extinguish the present. Or, even worse, the consequences of interaction with other species in its new environment could cause an ecosystem disruption with unforeseeable consequences. It could be even more apocalyptic if the resurrected species acted as a reservoir of viability for new species of viruses that could generate diseases unknown to humanity.

Should we do everything we can do?

It’s clear that de-extinction isn’t just a technical problem. Nor is it just an ecological problem. Nor is it even a huge legal problem , as it’s hard to see how the biological, ecological, civil, and criminal liabilities of a non-natural biological species are regulated… The real problem, in my opinion, is fundamentally ethical in nature.

While there is unanimous agreement that pure science should be free from any restrictions, the same is not true of applied science and biotechnology . The practical development of scientific advances should not respond—or at least not solely—to criteria of economic profitability, much less to more or less spectacular circus whims. Strict understanding of the consequences of biological advances, combined with a deep ethical sense of experimental development, must prevail over individual and corporate interests.

From this perspective, I fear that de-extinctating species would not be the best option. Much more interesting than creating Jurassic Parks would be applying all this knowledge to preventing the extinction of species that, while still alive today, require rapid intervention if we want to keep them on the planet.

Author Bio: A. Victoria Andrés Fernández is Associate Professor in the Department of Animal Biology at the University of Malaga