Colossal Biosciences Creates Woolly Mouse in Quest to Revive the Woolly Mammoth by 2028

Colossal Biosciences, a biotech company aiming to bring back extinct species, has taken a major step toward its goal of reviving the woolly mammoth. The company recently announced the successful creation of a genetically modified mouse with mammoth-like fur, a breakthrough that could pave the way for large-scale de-extinction efforts. Using CRISPR gene-editing technology, scientists engineered these “woolly mice” by introducing mammoth genes into their DNA. While this achievement is significant, experts warn that resurrecting a full-sized woolly mammoth is still a long way off.

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How Colossal Biosciences is Using Genetic Engineering for De-Extinction

Colossal Biosciences’ mission revolves around using cutting-edge genetic engineering to revive long-extinct species. The company has set an ambitious goal to recreate the woolly mammoth by 2028. While this sounds like science fiction, the company has already secured hundreds of millions in funding to develop the necessary technology.

Mapping the Woolly Mammoth Genome

To bring back the woolly mammoth, scientists first mapped its entire genome by analyzing preserved DNA from fossils. They then compared this genetic data with the DNA of the mammoth’s closest living relative, the Asian elephant. By identifying the key genes that allowed mammoths to survive in extreme cold—such as those responsible for thick fur and fat storage—researchers developed a strategy to reintroduce these traits into living animals.

Why a Woolly Mouse?

Instead of jumping straight into elephant-sized genetic experiments, Colossal Biosciences chose to test its methods on mice. Mice reproduce quickly, are easy to study, and provide a controlled environment for observing genetic changes. By successfully creating a woolly mouse with fur resembling that of a mammoth, the company demonstrated that mammoth genes can be expressed in a living animal.

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How the Woolly Mouse Was Created Using CRISPR Technology

The development of the woolly mouse relied on CRISPR gene-editing technology, a revolutionary tool that allows scientists to make precise modifications to DNA.

The Genetic Editing Process

1. Identifying Key Mammoth Genes – Scientists located mouse equivalents of the genes responsible for mammoth fur.
2. Editing Mouse Embryos – Using CRISPR, researchers introduced these mammoth-like genes into mouse embryos.
3. Implanting the Embryos – The modified embryos were implanted into surrogate mouse mothers, who later gave birth to the woolly mice.

The Woolly Mouse’s Traits

The genetically engineered mice displayed thick, textured fur resembling that of a woolly mammoth. This suggests that the inserted mammoth genes functioned as expected, producing traits adapted for cold environments. However, further testing is needed to confirm whether these mice have improved cold resistance.

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Testing Cold Adaptation in Woolly Mice

While the woolly mouse represents a significant step in genetic engineering, its ability to withstand cold temperatures remains untested.

Cold Tolerance Experiments

Colossal Biosciences plans to study the mice in colder environments to determine if their modified fur provides better insulation. These experiments must first be approved by the Institutional Animal Care and Use Committee (IACUC), which oversees ethical animal research. If approved, the woolly mice could provide crucial insights into how mammoth genes function in a living organism.

Why This Matters for the Woolly Mammoth Revival

If the woolly mouse proves successful in cold environments, it could provide evidence that these genes would help a future woolly mammoth survive in arctic conditions. This would be a critical milestone toward reintroducing mammoth-like elephants into the wild.

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Colossal Biosciences’ Funding and Expanding Ambitions

Colossal Biosciences has quickly become a major player in the field of genetic engineering.

A $10.2 Billion Valuation and Massive Investment

In January 2025, the company announced a $200 million funding round, bringing its total valuation to $10.2 billion. Investors have been impressed with the rapid progress of its de-extinction technology, fueling confidence in its long-term goals.

Beyond Mammoths: The Return of Other Extinct Species

Colossal Biosciences isn’t stopping with the woolly mammoth. The company is also working on de-extincting:

• The Tasmanian Tiger – A carnivorous marsupial that disappeared in the 20th century.
• The Dodo Bird – An iconic flightless bird that vanished in the 1600s.

By applying its gene-editing techniques to multiple species, the company hopes to establish a framework for bringing back extinct animals and even preserving endangered species.

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Challenges in Reviving the Woolly Mammoth

Despite the excitement, experts warn that creating a fully functional woolly mammoth is significantly more complex than modifying a mouse.

Genetic Differences Between Elephants and Mammoths

David Gold, a paleobiology professor at UC Davis, points out that while producing mammoth-like fur in mice is exciting, there are hundreds of genetic differences between mammoths and elephants. Overcoming these differences will require significant advancements in genetic engineering.

Technical and Ethical Challenges

1. Modifying an Elephant Embryo – Unlike mice, elephants have much longer reproductive cycles, making experiments slow and expensive.
2. Creating a Viable Hybrid – Scientists need to ensure that modified elephant embryos can develop into healthy animals.
3. Ethical Concerns – Some argue that resources should be focused on protecting existing species rather than reviving extinct ones.

While Colossal Biosciences is optimistic, these challenges highlight the long road ahead before a true woolly mammoth can be brought back.

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Colossal Biosciences Calls the Woolly Mouse a “Watershed Moment”

Despite the hurdles, Colossal Biosciences sees the woolly mouse as a major proof of concept.

A Breakthrough in De-Extinction Science

Co-founder and CEO Ben Lamm called the woolly mouse a “watershed moment” for the company’s mission. He emphasized that the genetically modified mice were born healthy and displayed the exact traits scientists had predicted.

A Step Closer to De-Extinction

Lamm also noted an unexpected result: the woolly mice were much cuter than expected. While that may not be a scientific metric, it underscores the excitement surrounding the project. With this breakthrough, Colossal Biosciences moves one step closer to proving that de-extinction is possible.

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What’s Next?

The successful creation of a woolly mouse marks a major milestone in the quest to bring back the woolly mammoth. While significant challenges remain, this experiment shows that mammoth genes can be successfully introduced into living animals.

The coming years will determine whether Colossal Biosciences can scale this technology to larger animals like elephants. If successful, the dream of seeing a woolly mammoth roam the Earth once again could become a reality. Until then, the woolly mouse serves as a small but fascinating glimpse into the future of genetic science.