Opinion ‘De-extinction’: Has an American company brought the dire wolf back from the dead?

A month ago, this same company, which was valued at $10 billion in January, had announced the birth of “woolly mice” in an effort to bring back the woolly mammoth, which lived from the Middle Pleistocene to the Holocene epochs.

The dire wolf

Dire wolves (Aenocyon dirus) were large canines that dominated southern Canada and the US before they went extinct about 13,000 years ago. They resembled the grey/ gray wolves (Canis lupus) of today, but were larger, with white coats. A dire wolf could be 3.5 feet tall, more than 6 feet in length, and weigh up to 68 kg.

Dire wolves hunted horses, bison, and possibly mammoths. When many of those prey species became extinct — probably partly due to human hunters — the dire wolf may have also gone extinct.

In recent years, the species found widespread recognition because of HBO’s Game of Thrones and George R R Martin’s A Song of Ice and Fire series of fantasy novels, on which the TV show is based. (The dire wolf is the sigil, or mascot, of House Stark.)

Colossal claim

The company has reported the birth of three genetically modified grey wolf pups, which it claims are “functional copies of something that used to be alive”, that is, dire wolves.

Two male pups, Romulus and Remus, were born to surrogate dog mothers in October, and a female called Khaleesi — named after a character in Game of Thrones — was born in January.

Colossal has kept the wolves on a private 2,000-acre facility at an undisclosed location in the northern US, where they are being observed and cared for.

‘De-extinction’ process

Scientists at Colossal contacted museums and laboratories for dire wolf specimens and got access to a tooth thought to be about 13,000 years old, and a 72,000-year-old skull.

“Inside the skull is the petrous, or inner ear bone, which is a good source of well-preserved DNA,” Beth Shapiro, Colossal’s chief science officer, told USA Today.

From these two specimens, Shapiro and her team were able to recover enough DNA to create two dire wolf genomes — an organism’s complete set of genetic information. They then compared these genomes to those of other canid species, including coyotes, jackals, dholes, and other wolves.

“Using the genetic data, researchers could confirm the grey wolf as the closest living relative of the dire wolf — they share 99.5% of their DNA code,” the USA Today report said.

The scientists then used gene editing to make 20 unique edits to 14 genes in the grey wolf genome. Of those, 15 were meant to reproduce extinct dire wolf gene variants such as a light-coloured coat, hair length, coat patterning, body size and musculature.

Subsequently, fertilised “dire wolf” eggs were implanted into surrogate dog mothers.

Really dire wolves?

Colossal says the pups are not 100% the same as the now-extinct dire wolves. The question, then, is: Are these pups really dire wolves or just gene-edited grey wolves?

According to Colossal, grey wolves and dire wolves share 99.5% of their DNA. However, they are still very distinct from one another.

“Since the grey wolf genome is around 2.4 billion base pairs (the fundamental units of DNA) long, that still leaves room for millions of base pairs of differences,” a report in the New Scientist noted. Also, a 2021 study published in the journal Nature had reported that grey wolves and dire wolves, which were earlier thought to be very closely related, last shared a common ancestor around 6 million years ago. The two species only look similar.

According to Shapiro, the answer to the question has to do with how one defines a species.

“Species concepts are human classification systems, and everybody can disagree and everyone can be right… You can use the phylogenetic (evolutionary relationships) species concept to determine what you’re going to call a species… [but] we are using the morphological species concept and saying, if they look like this animal, then they are the animal,” she told New Scientist.

Uncertain return

Even if Colossal’s pups are indeed dire wolves, the species probably isn’t “reborn” yet. Romulus, Remus, and Khaleesi do not have parents, they have never met any other wolves, and they do not know how to hunt.

They are not allowed to breed, and Colossal expects to genetically engineer just three to five more of the animals.

Most likely, these “dire wolves” will become the second species on the planet to be brought back to life only to die again. The first was the bucardo, a mountain goat from the Pyrenees, Europe.