"Resurrecting Legends: The Genetic Revival of the Dire Wolf"

On April 7, a biotechnology company in Texas, U.S., named Colossal Biosciences announced that they had resurrected a dire wolf, a large dangerous predator that went extinct more than 10,000 years ago. In a paper uploaded by the company on April 11, Colossal Biosciences claimed that the genomes of the gray wolf and the dire wolf are 99.94% identical, implying that 2.445 billion of the 2.447 billion base pairs were in the same places in the two genomes.Scientists extracted DNA from ancient dire wolf fossils, including a 13,000-year-old tooth and a 72,000-year-old ear bone.They sequenced the dire wolf genome and identified 20 key genetic differences between dire wolves and their closest living relative, the gray wolf.It takes surprisingly few genetic changes to spell the difference between a living species and an extinct one. Like other canids, a wolf has about 19,000 genes. Creating the dire wolves called for making just 20 edits in 14 genes in the common gray wolf, but those tweaks gave rise to a host of differences.The dire wolf genome analyzed to determine what those changes were was extracted from two ancient samples—one a 13,000-year-old tooth, the other a 72,000-year-old ear bone.

The scientists produced 45 engineered ova, which were allowed to develop into embryos in the lab. Those embryos were inserted into the wombs of two surrogate hound mixes, chosen mostly for their overall health and for their size, since they’d be giving birth to large pups. In each mother, one embryo took hold and proceeded to a full-term pregnancy.On Oct. 1, 2024, the surrogates gave birth to Romulus and Remus.They both were male. A few months later, repeated the same procedure with another clutch of embryos and another surrogate mother. On Jan 30, 2025, that dog gave birth to Khaleesi a female.

Dire wolves are apex predators that fed on the beings around them . Standing 96.5 cm (38 inches) tall at the shoulder, many dire wolves grew up to 178 cm (70 inches) in length and weighed between 59 and 68 kg (roughly 130 and 150 pounds).The dire wolf differed from the modern gray wolf in several ways: it was larger and it had a more massive skull, a smaller brain, and larger teeth than modern wolves, with relatively light limbs.They Often took large prey.Horses were important prey; sloth, mastodon, bison and camel were less common prey. Fed on medium to large hooved animals. Ate both ruminants and non-ruminants A pack of dire wolves could even have preyed on adult bison. They may have also had supplemented diet with smaller prey species.

In a study of the general health of several Pleistocene animals (as revealed by x-rays of their bones), dire wolves' health appeared no different than that of modern healthy populations of carnivores. Bone x-rays can show lines where normal growth is halted and later resumed (called Harris lines). Broken teeth a feature of living carnivores that often crack large bones. Tooth breakage data in fossils must be combined with accurate estimates of an animal's age (so that estimates of breakage are independent of an animal's age) Dire wolf fossils from La Brea at 15,000 years ago show more tooth breakage than ones from 12,000 years ago. Perhaps this reflects more complete consumption of carcasses at 15,000 years ago and more competition with other predators than at 12,000 years ago when predator densities may have been lower.

They thrived in open grasslands and plains, forested mountain regions, and even tropical wetlands. Fossil remains have been discovered in diverse environments, including arid savannas in South America and the steppes of eastern Asia. The species was considerably widespread throughout North America and parts of western South America, and fossil remains have been found in Florida, the Mississippi River valley, the Valley of Mexico, Bolivia, Peru, and Venezuela.