Colossal’s first gene-edited wolves turn 2 as company reports on healthConnor McCroryThu, October 15, 2026 at 11:25 PM UTC
Colossal Biosciences says its first gene-edited wolves are healthy and displaying pack behavior -Credit:Instagram (Instagram)Colossal Biosciences says its first gene-edited wolves are healthy and displaying pack behavior as Romulus and Remus turn 2
Every animal on Earth eventually gets a field guide, the dog-eared book that tells you how big it grows, what it eats, and how it treats its own kind.
The dire wolf’s was left unfinished more than 10,000 years ago, with nothing but bones to fill the pages. Now Colossal Biosciences is writing the rest. Its famous pack, brothers Romulus and Remus, who turned two on October 1, and their sister Khaleesi, born four months later, have reached adulthood.
Now, the company is sharing its fullest picture yet of what living dire wolves are actually like.
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When the snow-white pups were unveiled in 2025, the questions came as fast as the headlines. Would animals raised by people grow into the real thing? Would they be healthy? Would they act like wolves? Two years in, the answers arrive with numbers attached. Romulus weighs 134 pounds, Remus 132. Their growth plates are closed, and their furry white bodies are indeed in ideal condition.
Each wolf has now had two complete veterinary workups a year apart, from whole-body CT scans to heart ultrasounds and bloodwork, building a health record no animal from an extinct lineage has ever had.
“Our dire wolf pack is tracking directly with the morphometrics documented in the ancient dire wolf fossil record,” says Colossal CEO Ben Lamm, “offering further validation of our de-extinction process.”
But the most telling chapter in this new field guide isn’t about size; it’s about behavior.
Some scientists predicted that wolves raised under human care, with no elders to learn from, would not ever truly live as a pack.
Instead, these three built one themselves. Remus leads. Romulus and Khaleesi defer to him and consult with him; their only real squabbles come at feeding time.
They hunt cooperatively across a wide, naturalistic enclosure. They gorge after a big meal and fast in between, the same feast-and-famine rhythm wild canids live by. Nobody had to teach them that.
After, came the entry nobody expected to write. Khaleesi, it turns out, is chromosomally XY, the genetic signature of a male.
But her Y chromosome never switched on, and she developed as an entirely normal female, an outcome documented before in cloned dogs, naturally bred dogs, and wild wolves. Her recent planned spay, the first and only surgery any of the three has needed, confirmed it.
Lamm is clearly enjoying the twist. “Colossal got an early ‘life finds a way’ moment,” he says, “which should make all the Ian Malcolm meme creators happy.”
Two years ago, the dire wolf lived only in museum drawers and on fantasy television.
Today it has weight, a pecking order, a hunting style, and a medical chart; the first new pages added to its story since the Ice Age ended. For the first time, the wolves themselves hold the pen.
Source: Nature