This was an exciting week for Pleistocene megafauna geeks. Monday, we learned of the de-extinction of maybe the greatest canine predator ever to roam Earth.
Yes, the dire wolf has returned.
Well, sort of. What’s been created is more a close approximation of a dire wolf, with genes that nearly match the real thing.
Colossal Biosciences, an American biotechnology and genetic engineering company based in Texas, used CRISPR, the gene-editing technology that helped create the COVID-19 vaccine, to de-extinct dire wolves. In 2021, a different group of scientists extracted complete DNA from dire wolf fossils. Following that genetic map, Colossal Biosciences used CRISPR to make 20 modifications to modern gray wolf DNA so that it would replicate the physical characteristics of dire wolves.
That edited DNA replaced the genetic coding in modern wolf embryos, and those embryos were implanted in large dogs. The result was three pups whose wolfiness seems more dire than gray.
Dire wolves were larger cousins of modern gray wolves. They were more robust as well, and the skeletal remains — especially their massive skulls — suggest they were built to prey on the largest megafauna of the Pleistocene era. When most of those animals went extinct dire wolves followed, blinking out about 10,000 years ago.
The three de-extinct dires are living in a 2,000-acre enclosure in an undisclosed location in the northern U.S. These wolves are white, with manes much thicker than that of modern wolves, and the two males and one female appear on track to be larger as well when fully grown.
While CRISPR and our understanding of DNA is a remarkable tool for de-extinction, these dires are not exact replicas. Some dire wolf DNA sequences cause defects such as blindness in gray wolves. For that, Colossal Biosciences used modern wolf DNA mutations that created similar dire characteristics, without the defects.
In addition to genetic differences, what makes a wolf a dire is the ecosystem in which it exists. Bison are the lone remaining megafauna mammal that dires were built to kill. Also absent are saber-toothed cats such as Smilodon that dire wolves competed with for food.
So these wolves can’t be true dires and should never freely roam the wilds of North America. They are destined to be glorified zoo creatures.
Colossal Biosciences initially set out to de-extinct one of the dire’s probable prey species, wooly mammoths. That project required using the mammoth’s closest living relative, Asian elephants, as surrogates. This proved challenging, however, so the company set its sights on a more doable project. Dogs are essentially domesticated gray wolves, and while dires broke off from the modern canid lineage 4-5 million years ago, they are still closely related. And there’s been a lot of genetic and reproductive work with dogs that lent itself to this project.
Maybe Colossal Biosciences will get back to wooly mammoths or possibly Smilodons or my Pleistocene white whale, Irish elk, now that the company has demonstrated the possibilities of its technology. If so, we may need to identify an isolated island in the temperate zone where we can create a Pleistocene Park.
A more practical benefit of this research will be saving and recovering extant species that are threatened or endangered. Colossal Biosciences is already involved in the recovery project for critically endangered red wolves native to the eastern United States. The possibilities here seem limitless.
Of course, I’m up for a safari in Pleistocene Park. I don’t want to hunt; my dream is to watch an Irish elk use its gigantic antlers to sweep aside a marauding pack of dires, despite these species never sharing the same continent in life.
Still, it’s in combating the modern extinction crisis, not fantasy wildlife amusement parks, where we will realize the true value of this work.
In the meantime, I’ve one request of Colossal Biosciences: we need to hear the howl of the dire wolf. Stat!