Howls pierce the air. Wolves are telling each other food is near. But these aren’t just any wolves. Their large size and white fur are features of an animal that became extinct 10,000 years ago—the dire wolf!

In 2024, a company called Colossal Biosciences bred three pups that look similar to ancient dire wolves. Could the technology these scientists used be a new way to combat extinction?

Howls fill the air. Wolves are telling each other food is near. But these aren’t just any wolves. They are huge and have white fur. They look like an animal that went extinct 10,000 years ago. It was called the dire wolf!

A company called Colossal Biosciences bred three pups in 2024. They look like ancient dire wolves. Could this science stop other animals from going extinct?

Extinction, or the dying out of a species, can cause harm to entire ecosystems. For example, beavers build dams that slow the flow of rivers. If beavers went extinct, rivers would flood more often, killing plants and animals.

Colossal’s mission is to prevent this type of ecosystem damage—by making sure species aren’t lost for good! To do this, Colossal scientists are trying to bring back  inherited traits of extinct animals to their living relatives. The company calls this effort “de-extinction.”

When a species becomes extinct, it dies out in the wild. This can cause harm to entire ecosystems. For example, beavers build dams. Dams slow the flow of rivers. What if beavers went extinct? Rivers would flood more often. The flooding would kill plants and animals.

Colossal’s mission is to make sure species aren’t lost for good! This could help save their ecosystems. Colossal scientists give inherited traits of extinct animals to living relatives. The company aims to re-create lost species. It calls this effort “de-extinction.”

To test their technology, Colossal scientists turned to the ancient dire wolf. Dire wolf DNA, or inherited material, is similar to the DNA of modern gray wolves and dogs. That made it easier to work with.

First, scientists analyzed DNA from preserved dire wolf bones. Then they compared it to the DNA of a gray wolf.

Next, the scientists used a technology called CRISPR to change the DNA in a few cells from a living gray wolf. Parts of DNA control how an animal looks. Colossal changed some of these parts in the gray wolf cells’ DNA to match the ancient dire wolf DNA.

Colossal scientists wanted to test their science. So they turned to the ancient dire wolf. They looked at dire wolf DNA, or inherited material. It’s like the DNA of modern gray wolves and dogs. That made it easier to work with.

First, scientists studied DNA from preserved dire wolf bones. Then they compared it with the DNA of a gray wolf.

Next, the scientists used a technology called CRISPR. It changed the DNA in a few cells from a living gray wolf. Parts of DNA control how an animal looks. Colossal changed some of these to match the ancient dire wolf DNA.

Finally, the scientists placed the changed cells inside a female dog. That dog gave birth to three pups: Romulus, Remus, and Khaleesi. The pups tackle each other and howl together like gray wolves do. But they have the large paws, wide skulls, and the thick white fur of dire wolves.

Does that mean dire wolves are no longer extinct?

Nope! “These are gray wolves that look slightly different,” says Anders Bergström. He’s a scientist who studies how traits are passed down at the University of East Anglia in the United Kingdom. There are many more differences between gray wolf and dire wolf DNA than what Colossal scientists changed.

Plus, the pups probably don’t behave exactly like their ancestors. There are no adult dire wolves to teach them how! “An animal is more than what’s written in its DNA,” says Beth Shapiro, the lead scientist at Colossal.

Finally, the scientists placed the changed cells inside a female dog. That dog gave birth to three pups. Their names are Romulus, Remus, and Khaleesi. The pups tackle each other. They howl like gray wolves do. But they have the large paws, wide skulls, and the thick white fur of dire wolves.

Does that mean dire wolves are no longer extinct?

Nope! “These are gray wolves that look slightly different,” says Anders Bergström. He’s a scientist at the University of East Anglia. It’s in the United Kingdom. He studies how traits are passed down. Colossal scientists only changed a few bits of DNA. Gray wolves and dire wolves have many more differences.

Plus, the pups probably don’t act exactly like their ancestors. There are no adult dire wolves to teach them how! “An animal is more than what’s written in its DNA,” says Beth Shapiro. She’s the lead scientist at Colossal.

We may never bring extinct species back. But Colossal’s technology may be useful in preventing more extinctions.

Today 47,000 species—from tigers to turtles— are at risk of dying out. Often, human activities such as cutting down forests are to blame.

Colossal scientists plan to use their process of changing DNA to protect vulnerable species and their ecosystems. The goal: Prevent the loss of one species from triggering the loss of others.

“I have hope for how we can use these tools,” says Colossal scientist Matt James.

We may never bring extinct species back. But Colossal’s science may be useful in stopping more extinctions.

Today 47,000 species are at risk of dying out. They include animals from tigers to turtles. Often, human activities like cutting down forests are to blame.

Colossal scientists plan to use their process of changing DNA. They want to protect species and ecosystems under threat. The goal is to stop the loss of one species causing the loss of others.

“I have hope for how we can use these tools,” says Colossal scientist Matt James.