Clone Chaos: Colossal’s Adorable New Wolves – But Do They Spell Trouble?
In addition to placing dire wolves more firmly within the Canidae family tree (they are slightly closer to jackals than to gray wolves, but more than 99.9% identical to both at a genetic level) and determining when dire wolves split from the pack (around 4 million years ago), the team identified approximately 80 genes where dire wolves appeared to significantly differ. This would serve as a foundational list if one sought to transform a gray wolf into a dire wolf.
Crying wolf
Colossal then initiated a process utilizing base editing, a modern evolution of the CRISPR gene-modification technique, to introduce some of those specific DNA variations into the blood cells of a gray wolf housed in their labs. The company hoped that each additional edit would incrementally make the animal more dire-wolf-like, even if it meant altering just a single letter in a gene.
Shapiro states that all edits involve “genetic enhancers,” segments of DNA that govern how intensely certain genes are expressed. These can affect the growth size of animals as well as alter the shapes of their ears, faces, and skulls. This approach is less dramatic than intervening directly within a gene, which would alter the protein produced. Instead, it is considered a lower-risk strategy—more like adjusting knobs on an unfamiliar radio than cutting wires and swapping circuits.
This allowed the scientists to engineer what could become the standout trait—the striking white fur. Shapiro mentions that the genomic data suggested that dire wolves might have exhibited lighter coats. However, the specific pigment genes involved carry risks of albinism, deafness, and blindness, which the team sought to avoid.
At this point, Colossal chose a more straightforward approach. Rather than attempting to reproduce the precise DNA variants found in dire wolves, they opted to disable two genes entirely. In dogs and other species, the absence of these genes is associated with lighter fur.
The decision to give the wolves white fur did lead to striking images of the animals. “It’s the most notable feature about them,” remarks Mairin Balisi, a paleontologist who studies dire wolf fossils. However, she expresses skepticism regarding its accuracy: “A white coat might be suitable for snowy environments, but one of the primary habitats of dire wolves was around Los Angeles and the tar pits, which were not snowy, even during the Ice Age. If you observe mammals in this region today, they are not white. I find the claim that dire wolves are back to be perplexing.”
Bergström shares similar doubts, asserting that the edits may not suffice to classify the animal as a dire wolf. “I question whether 20 changes are adequate to convert a gray wolf into a dire wolf. It likely requires hundreds or thousands of changes—no one truly knows,” he states. “This remains an unresolved question in biology. Debates persist regarding the extent to which numerous minor differences establish a species as distinct, versus a limited number of major-effect variations. The consensus is unclear, but I lean toward the ‘many small differences’ perspective.”
Some genes exhibit significant, visible effects—altering a single gene can render a dog hairless, for example. Yet, it may be many smaller changes that contribute to the size and appearance disparities between breeds, such as a Great Dane and a Chihuahua. Furthermore, Bergström notes that science has limited insights into which changes would influence behavior—even if we could deduce an extinct animal’s behavior from its genome, which remains unattainable.
