Did Scientists Actually Revive Dire Wolves, An Extinct Species?

One of the three dire wolves Colossal Biosciences had made.

Dire wolves, scientifically known as the Aenocyon dirus, roamed the Americas for about 200,000 years during the Pleistocene epoch and disappeared around 11,700 years ago. You may have seen them while watching Game of Thrones, or you might have seen three “dire wolf” pups on your social media feed recently.

Using the advanced gene editing technology CRISPR, Colossal Biosciences created a modern version of the original dire wolf through pieces of their DNA from fossils found throughout the Americas. Dire wolves have been gone for quite a while, so scientists needed to find special instructions to understand how dire wolves grew and evolved while they were on Earth. Part of the special instructions is DNA, or deoxyribonucleic acid, which tells scientists the exact steps of how dire wolves evolved and developed during their time. DNA is what tells the cells in all living things how to work together to grow. To provide a simple and brief overview of CRISPR, think of it as a pair of tweezers that can delete, insert, or change parts of our genome. The genome is the complete genetic information of any being; it determines our uniqueness, which includes everything: our height, hair color, blood type, etc.

Anyway, what is a dire wolf? First, dire wolves have prominent sagittal crests on their skulls, which are the bones connecting to their large jaw muscles. Second, the teeth of dire wolves are typically larger, sharper, and stronger than those of a modern wolf. Lastly, they have a larger skeleton.

So, to our next question, are dire wolves back? The short answer is no. The longer answer is perhaps not just yet. Colossal Biosciences' dire wolves are just modified versions of our gray wolves, even if they look like what we think dire wolves looked like back then (based on their fossils). The three pups made by Colossal Biosciences—Romulus, Remus, and Khaleesi—have snow-white fur, bigger bones than normal wolves, and seriously sharp teeth. These characteristics are similar to a dire wolf, but they aren’t a perfect match.

Here’s the truth: no scientist can build a complete genome map from just bits and pieces. DNA breaks down over time from the Earth's natural environment and chemicals, so scientists only have a few pieces of the puzzle to work with.

Basically, even with advanced gene-editing technology, bringing back a dire wolf or any extinct animal is impossible. One reason is, as previously mentioned, the way genetic material decays over time. Another substantial reason is the present limitations of gene-editing technology. As a fun fact, Colossal Biosciences made only around 20 changes across 14 genes in the “dire wolves,” so 99.9% of the dire wolves' genome is exactly the same as any modern-day gray wolf.

The same family environment that allowed dire wolves to evolve from their ancestors is extremely hard, if not impossible, to recreate. While the modern gray wolf is their closest relative, it is still not a precise match of the species from which dire wolves descended from. Therefore, our modern gray wolves cannot replicate the behaviors snd characteristics that gave rise to dire wolves. Differences in nutrient transfers and hormonal balances between a surrogate gray wolf, as in the case of Colossal Biosciences, and a baby “dire wolf” also play a role. You might think that these differences are not that important, but scientifically, all of this can affect a lot of things, especially when it comes to stuff like brain development and organ formation.

The early life stages of a real dire wolf were also different from those of a modern gray wolf. The fossils of dire wolves were typically found close to each other, as evidenced by the Talara site in Peru, where scientists found 4,500 dire wolf fossils. This suggests that dire wolves lived in social groups, somewhat similar to modern wolves. So, while we can partially recreate this aspect of the dire wolves’ social life, what we cannot do is fully replicate other aspects because the environment in which these dire wolves lived in is long gone due to human influences such as deforestation, pollution, and hunting.

Different wolf species exhibit varied behaviors, making it uncertain whether dire wolves acted like modern wolves or their other relatives. For instance, gray wolves (Canis lupus) follow a hierarchy led by alpha males and females, guiding the pack in hunting and traveling. In contrast, red wolves (Canis rufus) form smaller packs of five to eight due to physical differences and habitat factors. Red wolves inhabit southeastern and south-central North America, where prey is scarce, partly because early settlers hunted much of it. Smaller packs reduce competition for food. Conversely, gray wolves live in forests and grasslands with abundant prey and vast areas to cover, necessitating larger packs to hunt and collaborate effectively.

In the end, although this innovative project using CRISPR has achieved modified wolves that exhibit some physical traits of the dire wolves, these genetically modified wolves are not real dire wolves. Ultimately, while the scientific and technological innovation in these projects is exciting, they remind us of how difficult it is to revive a species. The intersection of genetics, developmental biology, and ecology reveals that reviving an extinct species is a technical challenge and a meaningful exploration into what truly defines an organism. Perhaps, future breakthroughs or innovations in gene editing will result in a real resurrection of dire wolves. Until then, we can only continue trying to complete the puzzle with the pieces we have.