Romulus and Remus, the gene-edited wolves created by Colossal Biosciences, have turned two, and the company says they have reached the size researchers predicted from dire wolf fossil records. Along with their younger sister, Khaleesi, the brothers are healthy and thriving under human care, giving scientists a rare opportunity to study how genetically engineered animals develop over time. The trio was introduced to the public in April 2025, when Colossal announced that it had edited gray wolf DNA to recreate selected traits of the extinct dire wolf, which disappeared more than 10,000 years ago. Although the animals resemble their ancient relatives, they are genetically edited gray wolves, not exact genetic copies of the extinct species.
These gene-edited wolves were created to bring back traits of a species extinct for over 10,000 years
