The dire wolf is not back: what the "de-extinction" announcement really means and why the future matters more than the past

18 Junho 2025

Escrito por Francisco H. C. Felix

In April 2025, headlines around the world announced the supposed “de-extinction” of the dire wolf, a species extinct for thousands of years, following the release of a preprint and a statement from Colossal Biosciences. De-extinction: The concept of attempting to recreate or restore extinct species using biotechnological techniques such as cloning, genetic editing, or selective breeding. To date, no full de-extinction has been scientifically achieved. But what really happened? The answer is more complex and interesting than the hype suggests.

Artistic reconstruction of the dire wolf (Canis dirus). Illustration by Sergiodlarosa, published under Creative Commons Attribution 3.0 Unported license. Source: Wikimedia Commons Dire wolf (Canis dirus): A prehistoric wolf species that lived in the Americas during the Pleistocene and went extinct about 10,000 years ago. It was larger and more robust than modern wolves.

What was (and wasn’t) done

Colossal Biosciences used genetic material from modern gray wolves, not dogs. One of the major methodological advances was the use of cloning from endothelial progenitor cells, which are normally found in very small quantities in the inner lining of blood vessels. Unlike traditional cloning techniques, which rely on tissue samples obtained by biopsy (and can be contaminated by differentiated cells), this approach requires only a blood sample and the specific separation of these progenitor cells—something that until recently seemed like science fiction, as in the movie ‘The 6th Day.’ Cloning: An asexual reproduction technique that generates a genetically identical organism to the original. It can be done by nuclear transfer, as in the case of Dolly the sheep, or by other laboratory methods.

The DNA of the gray wolves was then genetically edited using a CRISPR-Cas9 based technique, allowing for the modification of 20 DNA nucleotide positions in the original genetic material. These 20 changes were enough to give the resulting animals the appearance of a dire wolf. However, the original dire wolves had millions of base pairs different from modern gray wolves—so the modification is superficial and limited. CRISPR: A genetic editing tool based on a natural bacterial defense system, allowing precise, fast, and relatively inexpensive modification of DNA in organisms. It has revolutionized biotechnology and medicine.

After the genetic editing, the nuclei of these modified cells were transferred into gray wolf eggs whose nuclei had been removed, a step similar to the classic cloning technique used in the famous Dolly the sheep. The resulting embryos, containing the edited genetic material, could then be implanted for development.

The genetically modified gray wolf embryos were implanted into domestic dogs, which gestated and gave birth to three pups. Therefore, these are not dire wolves, but gray wolves modified to look like dire wolves.

The controversy increased in May 2025, when Colossal’s chief scientist publicly admitted that the animals created are not dire wolves and that there was, in fact, no de-extinction. This admission, widely reported in the media, reinforced the media-driven nature of the announcement and highlighted the importance of precise and transparent scientific communication.

Scientists and outlets such as Science and the BBC were clear: there is no real de-extinction, nor evidence that dire wolves are back. The announcement was, for the most part, a media stunt, as also pointed out by Universidade de São Paulo - USP.

The real milestone: CRISPR and the future

Despite the media exaggeration, the work represents a remarkable advance in the application of genetic editing in mammals, especially using CRISPR to insert genetic modifications similar to extinct species into modern genomes. This opens doors for research in biotechnology, animal and human health, and even for the conservation of endangered species—but not for “resurrecting” the past.

The immediate practical impact for ecology or species protection is zero. There are no benefits for the environment or biodiversity at this time. What we do have is a technological leap that could, in the future, revolutionize medicine, making it possible to create animals (and perhaps humans) resistant to diseases or with optimized traits.

The ethical debate and a disruptive future

The most relevant—and underdiscussed—aspect is the potential of genetic editing to create living beings with unprecedented characteristics. The “dire wolf” is just a symbol: the real dilemma is how society will deal with the possibility of profoundly modifying humans and animals. CRISPR technology could, in the medium and long term, transform health, but it also brings enormous ethical challenges. Bioethics: An interdisciplinary field that discusses the ethical, social, and legal boundaries of biomedical interventions such as cloning, genetic editing, and de-extinction. Essential for guiding responsible decisions in science.

Conclusion

The news of the dire wolf’s “de-extinction” is, in fact, a milestone for the future, not the past. The most important thing is not what was recovered, but what could be created. The debate about the limits and uses of genetic editing is just beginning.

Sources: