Three genetically modified wolf puppies, created to look like the extinct dire wolf, were recently born and are being closely watched at a secure U.S. facility, according to Colossal Biosciences. These puppies, now three to six months old, already weigh about 80 pounds and may grow up to 140 pounds. Dire wolves, which went extinct more than 10,000 years ago, were much larger than modern gray wolves. Scientists studied ancient DNA from fossils found in Ohio and Idaho to understand what dire wolves looked like. They then used CRISPR gene-editing technology to change 20 specific parts of gray wolf DNA and created embryos with these edits. These embryos were placed into domestic dogs, which gave birth to the new puppies.

This scientific achievement shows how advanced gene editing can help bring back features of extinct animals. However, experts say it is unlikely that a dire wolf can be completely recreated. Professor Vincent Lynch from the University at Buffalo explained that today’s science can only produce animals that look like dire wolves, not actual ones. Colossal also announced they have cloned four red wolves to help protect the species. Although the cloning process is less harmful than older methods, getting blood samples from wild wolves still presents difficulties. The U.S. Interior Department called the project a major step forward in science, with potential benefits for conservation worldwide.