Trying to Bring Mammoths Back to Life, Scientists Create a Strange New Creature

In a laboratory in Dallas, Texas, researchers at Colossal Biosciences have taken a striking step toward reviving one of the Earth’s most iconic lost creatures: the woolly mammoth. Using advanced gene-editing techniques, scientists have bred mice with long, woolly fur and unique metabolic traits modeled on the extinct mammoth, aiming to perfect a method that could ultimately bring back the species by 2028.

A Surprising Model for an Ancient Giant

The woolly mammoth, a massive relative of the modern elephant, vanished about 4,000 years ago. Its DNA has been remarkably preserved in permafrost across the Arctic, providing the genetic blueprint for de-extinction efforts. However, working directly with elephants raises serious ethical and practical issues. To overcome this, the team led by Colossal CEO Ben Lamm turned to mice, animals that reproduce quickly and whose genetics can be precisely altered with CRISPR technology.

The researchers focused on seven genes responsible for the mammoth’s distinctive shaggy coat — genes that affect hair length, texture, and color. Another gene they edited controls the animal’s accelerated lipid metabolism, a crucial adaptation that allowed mammoths to survive icy conditions. The result was a litter of mice sporting thick, golden fur reminiscent of their prehistoric inspiration.

Navigating the Complexities of Gene Editing

The process required extensive trial and error. Over five rounds of experiments, nearly 250 embryos were created, with fewer than half developing into viable 200 to 300 cell embryos. These were implanted into surrogate female mice, producing 38 pups that successfully expressed the woolly mammoth’s distinctive traits.

“The Colossal woolly mouse marks a watershed moment in our de-extinction mission,” Mr. Lamm said in a statement. “By engineering multiple cold-tolerant traits from mammoth evolutionary pathways into a living model species, we’ve proven our ability to recreate complex genetic combinations that took nature millions of years to create.”

Despite this breakthrough, the researchers stress that the mice are an initial proof of concept. Bringing back the mammoth itself involves editing dozens more genes related to blood vessels, fat distribution, and cold resistance. Each gene must be carefully studied and tested, initially in mice before any attempt with elephant embryos.

Aiming to Restore Lost Ecosystems

Colossal Biosciences sees its work not only as a scientific milestone but also as a potential tool for environmental restoration. The company hopes that reintroducing mammoths could help stabilize the Arctic permafrost, which plays a significant role in regulating global climate. The idea is that these giant grazers could reshape landscapes, slowing carbon release and combating climate change.

Alongside the mammoth, Colossal plans to pursue de-extinction projects involving the dodo and the Tasmanian tiger, known as the thylacine. Each species presents distinct scientific and ethical challenges, but together they represent a broad sweep of biodiversity that the company aims to recover.

Expanding the Frontiers of Conservation Technology

Beth Shapiro, chief science officer at Colossal, emphasized the broader implications of this research. “We do not argue that gene editing should be used instead of traditional approaches to conservation, but that this is a ‘both and’ situation,” she said. The technology may enhance efforts to protect endangered species by making them more resilient to rapidly changing environments.

While the woolly mice showcase the feasibility of complex genetic engineering, the path to a living mammoth remains fraught with challenges. The work involves not only scientific precision but also navigating ethical considerations about species revival. Still, the experiments have established a functional pipeline from gene editing to living organisms, a feat that many scientists regard as unprecedented.

The next stages will test whether these techniques can translate from small rodents to elephants, requiring long gestation periods and intricate care. For now, the woolly mouse stands as a symbol of what may be possible when modern biology meets ancient DNA.