The last woolly mammoth to walk the Earth perished nearly 4000 years ago on Wrangel Island, a desolate and remote island off the coast of Russia in the Arctic ocean.
It was a member of a small, isolated community of mammoths that was the last vestige of a once-thriving species that could be found roaming the plains of the northern hemisphere from Alaska to Siberia. Scientists still debate what caused the mammoths to finally go extinct, but the general consensus is that it was a combination of human hunting, genetic defects from inbreeding, and natural climate change, which shrank suitable mammoth habitat by a factor of ten.
The death of the woolly mammoth was a slow process that occurred over the course of several millennia. But the disappearance of the woolly mammoth may turn out to be less of an extinction and more of a hiatus. In recent years, the development of sophisticated gene-editing technologies has opened up the possibility of bringing the woolly mammoth back to life and rewilding it in its former Siberian stomping grounds. It’s an idea straight out of science fiction that is rapidly becoming science fact due to the efforts of a new company called Colossal, which aims to revive the mammoth by the end of the decade.
“There are a lot of people raising the alarm about climate change, but not enough people are talking about the loss of biodiversity and the loss of species.”
Through his research, Lamm came across the work of George Church, a world-renowned geneticist at Harvard University and a leader of the nascent de-extinction movement. For the past decade, Church and a handful of renegade biologists have been exploring the possibility of bringing extinct species back from the dead. This is an old dream, most memorably rendered in Michael Crichton’s Jurassic Park, but the technology to turn it into reality didn’t exist until very recently.
The technological breakthrough at the core of the de-extinction movement is CRISPR, a gene-editing tool that has been under development since the turn of the new millennium but has only recently found practical applications. CRISPR is a tool that functions as genetic scissors. It uses a strand of RNA to target a portion of a genome and deploys a protein called Cas-9 to remove that genetic material. As the strand of DNA repairs itself, it can be edited to express new traits that wouldn’t have occurred naturally.
CRISPR has been successfully used in a wide variety of applications over the past decade. It has produced disease-resistant livestock, it’s regularly used to edit mice genes for scientific research, and can even be used to edit the DNA of sperm, eggs, and embryos to induce desirable traits or remove unwanted ones. In 2019, a rogue scientist in China used CRISPR to create the first gene-edited babies who were resistant to HIV and was subsequently jailed after an international outcry about the ethics of genetically editing human embryos with such a new technology.
Church was a key figure in the development of CRISPR technology and immediately understood its implication for species revival. Under the auspices of a nonprofit called Revive & Restore, founded by Steward Brand of The Whole Earth Catalog fame, Church and other de-extinction believers set out to use CRISPR to bring animals back from the dead.
“Previously, technology has been barely used to slow or prevent extinction, but not to reverse it,” says Church. “Using CRISPR for the purpose of de-extinction is a breakthrough, with impacts far-reaching for species diversification efforts.”
One of the earliest Revive & Restore projects focused on bringing back the passenger pigeon, a species of North American bird that once numbered in the billions before being hunted to extinction in the early 20th century. But Church had his sights set on an even bigger project: He wanted to revive a woolly mammoth.
The process of reviving an extinct species is long and complex. The first step is to reconstruct the animal’s genome. This in itself is no easy task. When an animal dies, its DNA begins to break down, which means that any samples collected by scientists will be incomplete. But by piecing together as much of the genomic fragments as possible and comparing the extinct animal’s genome to that of a close genetic relative, it’s possible to get a nearly complete genetic map of the species.
When Church set out to revive the mammoth, scientists had already sequenced some of its genome by sampling mammoth remains that had been preserved in the frozen Siberian tundra. Church then compared the incomplete mammoth genome to the genome from the modern Asian elephant, which shares 99.6% of the mammoth’s DNA. This comparison helped Church and his colleagues at Harvard identify genes that were responsible for many of the mammoth’s key traits such as its cold tolerance, its small ears, and its shaggy fur.
In 2015, Church and a team of scientists at Harvard successfully copied genes from the Woolly Mammoth into the Asian elephant genome using CRISPR. It was a start, but a long way from a living, breathing mammoth. The next step would be to move from these fibroblast models— a generic cell found in connective tissue—to more specialized cells such as blood or liver cells to see how they’re affected by the genetic changes. After that, the team would be ready to move onto mammoth embryos, which could be grown in artificial wombs or carried by female Asian elephants.
The result wouldn’t be an exact replica of the woolly mammoth, but a hybrid of a mammoth and an Asian elephant. Still, it would be a functional woolly mammoth with all its hallmark traits and would mark the first time that a mammoth’s distinctive genes have been found in a living animal in more than 4,000 years.
When Lamm heard about Church’s work at Harvard and Revive & Restore, it immediately caught his interest. He’s always been drawn to paradigm shifting technologies and was intrigued by the possibility of using genetic engineering to slow the progress of climate change as well as the rapid extinction of species around the globe. It’s a concept that Lamm refers to as “thoughtful disruptive conservation.”
When Lamm reached out to Church in 2019, the duo hit it off and agreed to cofound Colossal to advance Church’s mammoth revival efforts. They began recruiting some of the world’s brightest geneticists, including Eriona Hysolli, who led the development of genome engineering techniques for mammoth de-extinction at Church’s Harvard lab.
“I think there’s a huge opportunity to leverage these technologies not just to bring back the mammoth, but to protect critically endangered species on Earth today,” says Lamm. “It’s not necessarily a new concept, but I feel like we have the right team, the right investors, the right partners to help bring this together in a way that we can ensure success.”
Lamm saw reviving and rewilding the woolly mammoth as a natural starting place for Colossal for several reasons. Megafauna like the woolly mammoth and modern elephants play a big role in shaping their natural environment. There’s evidence that suggests the woolly mammoth played an important role in sequestering carbon and other greenhouse gases by trampling on the tundra and exposing the arctic permafrost under the snow, which exposed the permafrost to the cold air that keeps its deepest layers frozen. But without the mammoths to kick up snow, cold temperatures can’t penetrate the deep permafrost, which means it melts faster in the summer and releases greenhouse gases that have been trapped for centuries.
By reintroducing the woolly mammoth to its natural habitat, it could provide a mitigating influence to global warming by helping keep greenhouse gases trapped in the permafrost.
There are also practical considerations to reviving the woolly mammoth. For starters, it’s easy to keep track of an animal that’s bigger than a truck. This is particularly important for studying and managing them once they’re reintroduced to the wild, which would be more difficult with smaller animals like insects or birds. Mammoths are also undeniably cool. This is key to drumming up public support for Colossal’s project and increasing awareness about the role that de-extinction can play in combating climate change.
In the future, Lamm says he can even envision tourists coming to check out woolly mammoths on a nature preserve. It’s an idea that’s also been explored by another revivalist, Sergey Zimov, who purchased 50 square miles of land in the Siberian Arctic and founded Pleistocene Park, where he’s been reintroducing modern species for nearly 3 decades to restore the grasslands.
“I think that ecotourism is a great way to increase awareness,” says Lamm. “My vision is to ensure not just the successful de-extinction of woolly mammoths, but ensuring Arctic rewilding. So in that process, if we people can go see these species in their natural habitat then I think that that's a huge win. But it’s not going to happen tomorrow.”
Lamm says he hopes Colossal can produce a woolly mammoth-elephant hybrid within four to six years. And while his vision for Colossal begins with the mammoth, reviving and rewilding this iconic species is just the starting point for a far more ambitious mission. He hopes one day to extend the technologies developed in the context of mammoth de-extinction to extend the presence of currently existing species in danger of extinction. He envisions creating a database of genomes for all endangered species, a library of life, that can stave off extinction events.
And with an estimated 150 species going extinct every day, it’s an innovation that simply can’t come fast enough.