5 DEADLY Extinct Animals Science Wants to Bring Back to LIFE

[00:00:00]On July 30th, 2003, in a lab in Spain, scientists watched an extinct animal take its first breath. A Pyrenean ibex, a wild mountain goat that had vanished from Earth 3 years earlier, was born again from a single frozen sliver of skin.

[00:00:18]For about 10 minutes, extinction ran backwards. Then the newborn's lungs failed, and the species went extinct a second time in the same hour it returned. But something had changed. The rule you were taught in school that extinct means gone, permanently, no exceptions, had just been broken for the first time in history. And today, it is not being broken by accident. It is being broken on purpose. Right now, in real labs, backed by more than half a billion dollars, scientists are not just racing to save the animals we are losing. They are trying to resurrect the ones we already lost. The giants. The hunters. The killers our ancestors once ran from.

[00:01:04]In this video, we are counting down five deadly extinct animals science is actively working to bring back to life.

[00:01:13]Let's start with number five.

[00:01:16]Number five isn't a dragon or a sea monster. It's a cow. But forget everything that word makes you picture.

[00:01:23]The aurochs was the wild ancestor of every cow alive today. And it was a completely different animal. The largest land mammal in all of Europe. A bull standing roughly 6 ft at the shoulder with horns that swept forward like spears. Our ancestors painted it on cave walls. The Greeks made it a god. The bull that carried off the princess Europa. And when Julius Caesar reached the forests of Germany, he wrote of a beast nearly the size of an elephant that in his words, spared neither man nor animal it caught sight of, and could never be tamed, even raised from a calf.

[00:01:59]This was not livestock. It was a monster that happened to be a cow. Then it lost.

[00:02:05]Habitat vanished, the hunting never stopped, and the last aurochs, a single female, died in 1627 in the Jaktorów Forest in Poland. One of the first extinctions humans ever recorded as it happened. But its DNA never fully disappeared. It's still scattered through the bloodlines of living cattle.

[00:02:25]A project called the Tauros Program is using that fact to breed the animal back. Crossing the most ancient aurochs-like breeds across [music] Europe, generation after generation, to rebuild the original beast from its own descendants. [music] But the result won't be a genetic clone.

[00:02:43]It'll be a stand-in. Built from scratch.

[00:02:46]So, if it has the size, the horns, the temper, and the role, [music] is it the aurochs returned, or just a convincing ghost wearing its shape? Back breeding is the slow road. Number four is what happens when scientists stop waiting on bloodlines and start rewriting the code itself.

[00:03:05]You know the woolly mammoth? 8 tons.

[00:03:08]12 ft at the shoulder. So large it weighed more than a dozen of those wild aurochs combined.

[00:03:15]What you might not know is how recently it was here. A final population survived on a remote Arctic island until about 4,000 years ago. The pyramids of Egypt were already standing while living mammoths still walked the earth. And a Dallas company called Colossal Biosciences, founded by entrepreneur Ben Lamm and Harvard geneticist George Church, intends to bring it back. Their tool is the Asian elephant, whose DNA is about 99.6% [music] identical to a mammoth's. The plan is to edit the differences, >> [music] >> the shaggy coat, the fat, the cold-resistant blood into elephant cells, [music] around 85 key genes in all. In 2025, they proved it could work on a smaller animal, a litter of gene-edited woolly mice born with thick, mammoth-like coats. The goal is a calf by the end of 2028 and not for a zoo.

[00:04:12]>> [music] >> They want to release herds into the Arctic, where the grazing could help slow the thawing permafrost. A resurrected animal brought back to fight climate change. The honest truth?

[00:04:25]What is born will not be a pure mammoth.

[00:04:28]It'll be a cold-adapted elephant carrying mammoth genes. Not every scientist believes 2028 is realistic.

[00:04:35]Some say a decade is closer. And there are 22 months of elephant pregnancy that as Colossal's own chief scientist admits are out of anyone's control. But if it works, a creature that vanished before recorded history walks again.

[00:04:51]Number three, never left living memory at all.

[00:04:55]Number three is the Tasmanian tiger, and unlike the mammoth, we have film of it.

[00:05:00]We watched the last one pace its enclosure.

[00:05:03]Officially the thylacine, it was Australia's only marsupial apex predator, a striped, dog-shaped hunter with a jaw that could yawn open almost 90°. The top predator of an entire continent, and we destroyed it on a lie.

[00:05:19]Farmers blamed it for killing sheep, a threat almost certainly exaggerated. And in 1888, the Tasmanian government put a bounty on its head. Over 21 years, more than 2,180 bounties were paid, and the population collapsed. The last known thylacine died on the 7th of September, 1936, in a Hobart zoo, locked out of its shelter overnight and dead from exposure. It had been granted legal protection just 2 months earlier.

[00:05:49]Too late. For almost 90 years, that was the end of it.

[00:05:53]Then, in 2022, scientists at the University of Melbourne's TIGRR Lab, led by Professor Andrew Pask, partnered with Colossal to undo it. Their breakthrough came from a 110-year-old thylacine head preserved in alcohol in a museum jar.

[00:06:11]From it, the team reconstructed a genome more than 99.9% accurate, the most complete ancient genome ever assembled for any species.

[00:06:20]Now, they are rewriting the genome of its closest living relative, a tiny carnivorous marsupial called the fat-tailed dunnart. With more than 300 edits already made to a single cell, the most edited animal cell on record.

[00:06:35]No thylacine has been born yet, and the work still needs full peer review. But, think about it. We spent a fortune to wipe this animal out, and now we are spending far more to bring it back. And if it returns, do you release an apex predator into a world that moved on without it 90 years ago?

[00:06:53]Number two is a predator scientists want even more, and the one they cannot have.

[00:07:00]Number two is the face of prehistoric death itself, the saber-tooth cat, Smilodon, armed with curved canine teeth up to 7 in long, set in a skull with jaws that could gape a full 120°.

[00:07:15]More than enough to drive those fangs into something the size of a young mammoth.

[00:07:20]The largest weighed up to 800 lb, heavier and more powerfully built than any lion or tiger alive.

[00:07:28]And it did not hunt alone.

[00:07:30]The thousands found together at the La Brea Tar Pits, more than 166,000 bones, suggested hunted in packs.

[00:07:38]It ruled North America until about 10,000 years ago.

[00:07:42]This is the predator de-extinction scientists talk about wanting most, the poster animal, and it's the one they cannot build. Here's why. The dire wolf, the mammoth, the thylacine, each has a close living relative to edit from.

[00:07:58]The saber-tooth does not. Smilodon split off from every living cat around 20 million years ago.

[00:08:05]To put that in perspective, a gray wolf is practically a sibling of the dire wolf. While the house cat on your couch is the saber-tooth's impossibly distant cousin, separated by an ocean of time.

[00:08:18]There is no near complete genome, no funded program, no surrogate alive close enough to carry it. So, the saber-tooth stays exactly where it is, wanted, imagined, and 20 million years out of reach, which makes what's already happened with number one almost impossible to believe.

[00:08:39]Number one is not a maybe. Number one already happened.

[00:08:44]The dire wolf was a real Ice Age apex predator, bigger and more powerfully built than the gray wolf, a pack hunter that brought down the largest prey of its world before vanishing roughly 12,500 years ago.

[00:08:59]For most of us, it lived only in fantasy, a creature out of Game of Thrones, except it wasn't fiction.

[00:09:05]And in 2024, it came back.

[00:09:08]Colossal Biosciences recovered ancient DNA from a 13,000-year-old dire wolf tooth and a 72,000-year-old skull, read its genome, then rewrote the key genes of a common gray wolf to match around 20 precise edits, 15 of them drawn straight from the extinct animal's own code. Dog surrogates carried the pregnancies. Two males, Romulus and Remus, were born in October 2024.

[00:09:35]A female, Khaleesi, in January 2025.

[00:09:40]The company revealed them that April.

[00:09:42]By 6 months old, the males already topped 90 lb, white-coated and broad skulled, the way their ancestors were.

[00:09:50]Today, they live on a secured preserve whose location is kept secret.

[00:09:55]But, here's the question the entire [music] scientific world is now fighting over.

[00:09:59]No ancient dire wolf DNA was >> [music] >> ever spliced into these animals. They're gray wolves with around 20 edits inside a genome that differs from a true dire wolf by potentially thousands of genes. Critics say, "That doesn't make a dire wolf. It makes a gray wolf sculpted to look like one."

[00:10:20]So, which is it? The first animal ever truly pulled back from extinction or the most convincing imitation a lab has ever produced?

[00:10:29]And there's a second question, quieter and stranger.

[00:10:33]If just 20 edits could put a living, breathing Ice Age predator on the ground in our lifetime, what's stopping them from doing it again?

[00:10:42]So, there you have it. Five deadly animals written out of existence, and five reasons that word might not mean what it used to.

[00:10:50]A wild bull rebuilt from its own descendants.

[00:10:54]A mammoth coded back to life inside an elephant. A striped predator reassembled from a head in a jar. A saber-tooth science aches for but can't yet touch.

[00:11:06]And a dire wolf already breathing on a private [music] preserve right now, at this very moment.

[00:11:12]Here's what makes this different from every monster story you've heard.

[00:11:16]The science isn't the unknown anymore.

[00:11:18]It's real. It's funded. One of these companies alone is worth more than $10 billion, and it's moving faster than the ethics or the public can keep up with.

[00:11:29]What's unknown is everything that comes after. Should we do this at all? What happens when an animal built for a vanished world wakes up in ours? Nobody has that answer yet. So, I want to hear from you.

[00:11:41]Of these five, which one should science actually bring back? And which should it leave dead and buried? And if you don't believe the dire wolf counts, tell me exactly why.

[00:11:51]Because the next creature we look into is the one researchers are most afraid to revive.

[00:11:58]Extinction used to be the end of the story.

[00:12:01]Not anymore.