De-Extinct Dire Wolves Reach Breeding Age at Biotech Preserve

Three dire wolf pups brought back from extinction using ancient DNA are now healthy and at breeding age, the biotechnology company responsible for the project said. The animals, created last year, continue to thrive on a 2,000-acre secure ecological preserve in an undisclosed location in the northern United States.

They are fed a diet of beef, deer, horse meat and specially formulated dried pet food. The company intends to create additional pups before the end of the year to broaden the genetic diversity of the group. The long-term goal is to establish a self-sustaining population that can breed naturally without ongoing human intervention.

Scientists compared the DNA of grey wolves, the dire wolf's closest living relative, with genetic material recovered from a 72,000-year-old skull found in Idaho and a 13,000-year-old tooth discovered in Ohio. They identified 20 key genetic differences and made targeted edits to the grey wolf genome.

The modifications introduced traits including a white coat, larger teeth, a more muscular build and a distinctive howl. The edited cells were inserted into egg cells from domestic dogs, which were then implanted into surrogate dogs. The pups were delivered by caesarean section to reduce risks during birth.

Dire wolves became extinct about 12,000 years ago toward the end of the last ice age as the climate warmed and prey animals declined. During the Pleistocene Epoch, from 2.58 million to roughly 11,700 years ago, they roamed the plains of what are now North and South America.

The species gained modern recognition after appearing in George R.R. Martin's best-selling fantasy novels, which were adapted into the television series Game of Thrones. The three pups were named Romulus and Remus, after the legendary founders of Rome, and Khaleesi, in reference to a character from the books.

The company has described the project as creating the world's first de-extincted species. It has acknowledged that the animals are not 100 per cent genetically identical to the ancient dire wolves but represent a close approximation through gene editing.

It has already created rodents with mammoth traits, dubbed "woolly mice," as a step toward reviving the woolly mammoth. Additional targets include the thylacine, also known as the Tasmanian tiger, which became extinct in 1936, the moa, a 3.6-metre-tall bird that once lived in New Zealand and disappeared between the 13th and 15th centuries, and the bluebuck, a rare antelope from southern Africa driven to extinction within 40 years of its scientific description.

Some scientists have criticised the approach, arguing that the resulting animals are genetically altered hybrids rather than true revivals of extinct species.

“The dire wolves are doing great. The three dire wolves live on a 2000-acre secure, expansive ecological preserve that allows us to monitor and manage them while providing them a semi-wild habitat to thrive in.”