If you’ve been excitedly awaiting the return of the woolly mammoth, you’ll have to be patient a little longer.
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you → await → mammoth
It was in 2021 that the newly established, Dallas-based company Colossal Biosciences announced plans to use modern gene-editing technology and DNA harvested from mammoth remains to manufacture a mammoth embryo, implant it in the womb of an elephant surrogate, and bring the great, gentle, six-ton beast—which vanished from the planet more than 4,000 years ago—back into the modern world.
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which → establish → world
In a recent conversation with TIME, Colossal CEO and co-founder Ben Lamm concedes that those goal posts have moved more than a little.
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posts → concede → little
“We are thinking it will be in the early 2030s,” he says.
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he → think → 2030s
“We don’t have a hard date.
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We → have → date
In just the past year, Colossal has learned vastly more about both the mammoth and the elephant genomes than has ever been known before, not only improving the odds that the mammoth can be brought back to life, or de-extincted, but also unpacking basic genetic science that could one day have knock-on effects for humans—including potentially increasing resistance to cancer.
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that → learn → cancer
Bringing back the dire wolf
Colossal proved its de-extinction chops in the spring of 2025, when it announced that it had brought the extinct dire wolf back to life, editing the genome of the closely related gray wolf to replicate the features of its vanished cousin—including a white coat, larger size, more powerful shoulders, wider head, larger teeth and jaws, more-muscular legs, and characteristic vocalizations, especially howling and whining.
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it → bring → coat
To work that genetic magic, Colossal scientists collected dire wolf DNA from an ear bone and a tooth unearthed in two ancient samples, sequenced the genome, and compared it to that of the gray wolf.
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scientists → work → wolf
They then harvested cells from a living gray wolf and made 20 edits on 14 genes using the CRISPR-Cas9 gene-editing tool, which produced the critical dire wolf characteristics.
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which → harvest → characteristics
Finally, they extracted the nucleus of the edited cell, inserted it into a domestic dog ovum whose own nucleus had been removed, and implanted the resulting embryo into the womb of a domestic hound.
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nucleus → extract → hound
Nine weeks later, the dire wolves were born.
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wolves → bear → ?
Why woolly mammoths are so hard to de-extinct
To do something similar with the woolly mammoth, Colossal discovered that the work would be a heavier genetic lift than their research teams had originally expected.
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teams → de → mammoth
The initial estimate was that it would take edits to about 60 genes to turn an elephant nucleus into a mammoth nucleus that could then be used to create a mammoth embryo.
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that → take → embryo
Now that number is about 150—and rising.
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number → rise → ?
Among the genes and regulatory switches that have been discovered are ones that shrink the mammoth ear to about one-tenth the size of an elephant’s ear.
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that → discover → ear
In the hot climates in which Asian and African elephants live, large, heavily vascularized ears serve as heat dumps, cooling the blood and the body as a whole.
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ears → live → whole
That would not do for the mammoth, which made its home during the Ice Age and needed to husband all the heat it could.
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it → do → heat
Mammoth tails are shorter than those of elephants too— for the same heat-retention reason—and Colossal scientists have found the gene that expresses that as well.
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that → find → that
The genetics of the mammoth’s characteristic heavy coat have also been unpacked.
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genetics → unpack → coat
Nearly all hairy mammals—humans included—have oil-secreting glands known as sebaceous glands in the skin.
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mammals → include → skin
The oil keeps individual hairs supple and prevents them from drying and breaking.
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oil → keep → them
Elephants, which have a very sparse covering of bristly hair across their bodies, were thought to be an exception to this rule.
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which → have → rule
That made the job of engineering a mammoth from an elephant more difficult, since mammoths surely had sebaceous glands to sustain their extravagant coat.
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mammoths → make → coat
But Colossal researchers conducted dissection and close examination of samples of elephant skin and found that that earlier received wisdom was wrong—the skin does contain small, rudimentary sebaceous-like structures.
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skin → conduct → structures
The trick now is to isolate the genes that code for the glands and edit them to create the fully developed version the mammoth will need.
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mammoth → isolate → version
The researchers also analyzed the makeup of elephant hair and determined that 90% of every strand is composed of nine different proteins.
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% → analyze → proteins
They then tracked down which genes code for that protein production and govern hair developmental patterns, which typically include periods of growth, rest, and regrowth.
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which → track → growth
In March 2025, Colossal revealed that it had created a small brood of 38 woolly mice, engineered with mammoth coding for shaggy hair written into their genome.
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mammoth → reveal → genome
The mice have thrived and bred, passing on their long, coarse hair to their pups.
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mice → thrive → pups
That was a good start, but mice aren’t mammoths, and to study how effective the genetic editing is, researchers will need to work with a larger mammal.
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researchers → study → mammal
Colossal promises that a woolly pig is coming, though the company does not say when it will be revealed.
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it → promise → ?
Digging deeper into the genome of the mammoth, Colossal scientists have extracted bits of its regulatory DNA and inserted them into living elephant skin cells and watched as regulators turned the behavior of the genes up or down—critical work if you want to design other genes to order.
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you → dig → genes
“It’s a little weird and Frankensteiny,” says Lamm, “but we’ve done that.”
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we → ’ → that
Potential implications for humans
Colossal researchers are also exploring one of the elephant’s more remarkable features: its resistance to cancer.
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researchers → explore → cancer
As a large-bodied mammal, elephants ought to be highly susceptible to the disease, especially considering that an elephant's body contains 100 times more cells than a human’s, creating more opportunities for cancer to occur.
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cancer → consider → opportunities
But cancer accounts for less than 5% of elephant deaths, compared to 16% for humans.
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cancer → account → humans
Both human and elephant cells are now known to carry a tumor-suppressor gene labeled TP53.
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cells → know → gene
When DNA in a cell is damaged—by cancer or other means—the gene codes for the release of the p53 protein, which either halts the damaged cell’s growth cycle to allow for repair, or, if the DNA is too corrupted, kills the cell.
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DNA → damage → cell
Humans carry two copies of the TP53 gene, while elephants carry 20—making for much greater cancer resistance.
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elephants → carry → resistance
Additionally, elephants but not humans carry what is known as an LIF6 gene, which also produces a p53 protein, one that specifically targets the mitochondria—an energy-producing organelle located in the cellular cytoplasm—of damaged calls, killing them before they can divide and spread.
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they → carry → them
…and 8 more, not listed.
